1 enero 2009

JANUARY 2009

Serving the hydro industry for 60 years: 1949-2009

Developments in dam safety

Highlighting hydro potential

RebuildingTaum SaukConstructing a new RCC dam at the US pumped storage scheme

0

28-29th April, Vancouver, BC, Canada

For further information on theevent, please contact:

Dorothee ArchambaultHead of Production, VIBevents

Tel: +44 (0)20 7753 4246Email: [email protected]

Assessing the resource• New estimates of micro (less than

100kW), mini (100kW-1MW) andsmall hydro (1MW-50MW)

• Identifying new locations

• Developing projects at existingstructures

• Training for engineers

• International perspectives

Local issues• Developing local operation and

management

• Operating experience

• Quick routes to licensing

• Assessing and minimisingenvironmental effects

Issues to be addressed at the event include:

Small Hydro 2009

New developmentmechanisms• Government funding initiatives

• Prospects for private funding

• Risk assessment and allocation

• Working with NGOs

• Experience exchange: casestudies on financing

• Public acceptance

• CDM certified projects

Steps in technology• Improving technology to increase

efficiency

• Refurbishing and uprating

• New equipment

• Software developments

• Micro to mini – keeping pacewith development

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Sponsorship & PromotionalOpportunitiesSponsorship is a good way of increasing brandawareness, which will help to generate preferenceand to foster brand loyalty. The Sponsorshipopportunities at Small Hydro 2009 will enable yourorganisation to reinforce awareness among keydecision makers in the international power industry.

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I N T E R N A T I O N A L

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© 2008 Progressive Media Markets Ltd.Printed by Williams Press Ltd.

CONTENTS

COVER: Rebuild work is currentlybeing carried out on the TaumSauk project in Missouri, US,following a catastrophic failure ofthe scheme’s upper reservoirin December 2005. See p28 formore details

39

42

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DAMENGINEERING

ModernPowerSystemsCOMMUNICATING POWER TECHNOLOGY WORLDWIDE

INTERNATIONAL WATER POWER & DAM CONSTRUCTION • ISSN 0306-400X Volume 61 Number 1 • JANUARY 2009 3

46 PROFESSIONAL DIRECTORY48 WORLD MARKETPLACE

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R E G U L A R S

4 WORLD NEWS10 DIARY

F E A T U R E S

INSIGHT12 A welcome return for hydro

A new study has established hydro’s important role inhelping Scotland meet its targets for renewable generation

15 Expanding research in IndiaA new research centre has been set up in India to tapinto the immense hydro market

SEISMIC ANALYSIS16 Fighting the fear of failure

Seismic risk at Toktogul hydro project in central Asia isthe focus of a NATO funded project

18 Analysing dam behaviourBosko J Guzina aims to help facilitate early discoveryand identification of tectonic activities at dams

PROJECT DEVELOPMENT23 Playing a jumbo role

Six tunnelling jumbos are being used to excavate thetunnels at La Confluencia project, Chile

24 The lowdown on RCCDelegates gathered in Australia for a structured trainingseminar on specialist RCC dam techniques

REFURBISHMENT28 Rebuilding Taum Sauk

Details on the rebuild work being carried out at TaumSauk pumped storage project in the US

34 Dam safety, emergency action plans and water alarm systemsMartin Wieland and Rudolf Mueller discuss the integralsafety concept for large dams

39 Back on the mendEssential remedial works – including rock injectiongrouting – are being carried out at Lower Carno dam

40 Sounding out fatigue cracksWe provide details on the use of the acoustic emissiontechnique to detect crack signals on turbine blades

SOFTWARE42 Getting to the bottom of it

Nick Forrest describes the development of Hydrobot – anew approach to hydro site identification

The paper used in this magazine is obtainedfrom manufacturers who operate withininternationally recognised standards.The paper is made from Elementary ChlorineFree (ECF) pulp, which is sourced fromsustainable, properly managed forestation.

15

WORLD NEWS

4 JANUARY 2009 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

WORLDNEWS

WORLDNEWS

www.waterpowermagazine.com

BRAZIL HAS SAID THATEcuador has resumed pay-ments to its national develop-

ment bank, BNDES, following monthsof argument over the performance of,and liability for, the San Franciscohydro power project.

Ecuador resumes paymentsfor San Francisco to Brazil

The Brazilian Government said thatpayments due to BNDES last monthwere received. It added that followingtalks in late November there should bethe return of its ambassador toEcuador shortly.

The row erupted in the middle oflast year following technical prob-lems with the San Francisco plant,which led to the Ecuadorian govern-ment clamping down on Braziliancontractor Odebrecht, which helpedbuild the plant and was heavily activein further infrastructure ventures inthe country.

Alleging poor per formance andboth financial costs and economicimpacts due to the technical prob-lems at the plant, the Governmenttook possession of the San Franciscoplant – as well as the Toachi-Pilaton

and Baba hydro projects andCarrizal-Chone water transfer project– and wanted money back fromOdebrecht.

The San Francisco plant (2 x115MW) began to generate commer-cially in the second quarter of 2007,and annually is to produce1,426GWh/year – or approximately12% of the country's electricity supply.

The run-of-river project began con-struction in 2003 under a 30-year con-cession and is upstream of the156MW Agoyan plant.

The concession was awarded bythe state electricity authority Conelecto the Hidropastaza consortium, com-prising Odebrecht as junior partnerand state-owned Hidro Agoyan.

The work at San Francisco was car-ried out on an engineering, procure-

ment and construction (EPC) basis byOdebrecht, Alstom and VA Tech Hydro.Detailed design was carried out byCaminosca and PCE Engenharia.

BNDES signed an agreement worthapproximately US$243M in 2000 withHidropastaza for the export ofBrazilian goods and services for theproject. The plant became operationalin 2007 and Odebrecht’s stake wastransferred to the Ecuadorian govern-ment.

The bank noted that Ecuador is thesecond biggest recipient of goods andservices exports it financed over 1997to August last year, and cited a totalof US$693M of funding.

The Brazilian Government said itwould continue to monitor the stateprogress of its economic relationshipwith Ecuador.

Ukraine interested in completing Rogun scheme

BILATERAL CO-OPERATIONTALKS have raised the possi-bility of Ukraine participating in

the completion of the Rogun projectin Tajikistan.

Following talks, the leaders of bothcountries said a priority for them wasto boost co-operation in hydro power,and noted that Ukraine had previous-ly supplied much of the equipment tothe sector in Tajikistan.

They added that further co-opera-tion in the construction of the Rogunproject was of interest to Ukraine, andthat a deal worth several hundred mil-lion US dollars was being considered.

The 2400MW project is underdevelopment on the Vakhsh river aspart of a hydro power cascade in thePamir-Altai Mountains. Work startedduring the Soviet era then stoppedwhen it ended.

Being designed by consultantLahmeyer International, the Rogunproject is planned to be completed intwo stages with initial and final damheights of 235m and 285m, respec-tively. It has also introduced a plan fora 175m high start-up dam that wouldbe integrated with the main structure.The benefit of the dam would be toallow earlier power generation.

At Stage 1, three of the plants600MW units would be installed butworking with only partial load. Thefourth unit would be added after Stage2 to complete the project.

The proposed layout – comprisingthe rockfill embankment dam and anunderground powerhouse, is gener-ally similar to the original design of1978, except for design and layoutchanges at spillways, mid-level outletand tailrace tunnels. A number of thepreviously built structures need to bedemolished and some unused tun-nels backfilled and sealed with con-crete plugs.

The consultant was hired by Rusal,the Russian aluminium conglomerate,acting as agent body on behalf of theRussian state in its co-operation withthe Government of Tajikistan to com-plete the project.

Plants on the meltwater-fed Vakhshcascade include Nurek (3000MW),Baipaza (600MW), Golovnaya(240MW), Perepadnaya (30MW) andCentralnaya (15MW).

Under construction on the river isthe 670MW Sangtuda-1(Sangtudinskaya-1) plant, and the220MW Sangtuda-2 project is beingdeveloped.

Tacoma Power in Cushman settlement dealAONE-TIME CASH PAYMENT, A

share of electric output and landtransfers have been agreed as

key parts of major claims settlementbetween US utility Tacoma Power andSkokomish Tribal Nation as part ofrelicensing the Cushman hydro powerscheme in Washington state.

To settle the US$5.8B damagesclaim, the parties agreed to TacomaPower making a US$12.6M one-timecash payment, providing a 7.25% shareof output from the Cushman No2 plant,and transfer of land valued at US$23M,including the Camp Cushman on LakeCushman, the 500-acre Nalley Ranch

and Saltwater Park on Hood Canal.Key further aspects of the licensing

agreement settlement include riverrestoration, in-stream flows, fisheriesand recreation.

The settlement will licence theCushman facilities for another 40 years,subject to approval by the FederalEnergy Regulatory Commission (FERC).Tacoma Power will also have the oppor-tunity to construct an additional gener-ator to capture some of the energy fromthe restoration flows being released intothe North Fork Skokomish River.

The Cushman scheme on theSkokomish river, in Mason County, com-

prises to dams and powerhouses: No1Dam, which is 339m long, impoundsLake Cushman, was completed in 1926and generates approximately 127GWhof electricity annually; the No2 Dam,which is 175m long, impounds LakeKokanee, was finished in 1930 and pro-duces 233GWh per year.

The original, 50-year federal licencefor the scheme expired in 1974 and until1998 the utility has operated the facili-ties under short-term licences. A broad-er licence was issued in 1998 and thenew settlement will modify the licence.

Mediation was used to start talkstowards a settlement, and both state

and federal agencies joined the nego-tiations a year and a half ago. Lastmonth, Tacoma Public Utilities Boardauthorised the proposed licensing set-tlement, and Tacoma City Councilauthorised the proposed damagessettlement.

Settlement agreement signersinclude Tacoma Power, SkokomishTribal Nation, Bureau of IndianAffairs, National Marine FisheriesService, United States ForestService, United States Fish & WildlifeService, Washington Department ofFish and Wildlife and WashingtonDepartment of Ecology.

WORLD NEWS

WWW.WATERPOWERMAGAZINE.COM JANUARY 2009 5

IWP&DCturns 60This year InternationalWater Power & DamConstruction celebrates its60th birthday – and whata 60 years it’s been!

Launched as a bi-monthlytitle in January 1949, thejournal has continuallybeen at the forefront ofdevelopments within thehydroelectric and damconstruction industry.

The very first issue ofIWP&DC contained anumber of informativepapers, including a reviewof power resources inEurope, a detailed reporton new hydro in Scotland,new developments inintake works and surgetanks, as well as a write-upon several large projects inCanada. This eclectic mixshowed how importanthydro was throughout theworld – and it is nodifferent today. This issue,for example, highlightshydro news from aroundthe globe, while detailingschemes in the US,Scotland and Asia.

The May 2009 edition ofthe journal however willbe our special anniversaryissue. Here we’ll look backthrough the years at someof the most importantdevelopments that haveshaped the face of theindustry. We’ll be high-lighting some interestingnews from the last sixdecades, while offering aninsight into future issues.We’ll also be featuringinterviews with industrystalwarts who willpinpoint the most impor-tant projects anddevelopments from thelast 60 years.

FERC approves first hydrokineticplant at existing hydro facility

THE FIRST HYDROKINETIC PLANTto be attached to an existinghydro power facility has won

approval from the US Federal EnergyRegulatory Commission (FERC).

Two hydrokinetic units are to beinstalled below a floating barge in thetailrace of the US Army Corps ofEngineers' Lock & Dam No2 on theMississippi river in Hastings,Minnesota. Each has a capacity of

35kW, said FERC, and the units areexpected to generate an average of364MWh of electricity per year.

The units are being supplied byHydro Green Energy, which said eachhas a nameplate capacity of 100kW.One was installed in Dec with thesecond due in April. The Corpsapproved the project last November.

FERC, in a statement, noted theimportance of the step because it

combined new technology with a con-ventional hydro power dam.

The existing hydro power facility atLock & Dam No2 has an installedcapacity of 4.4MW.

FERC's approval of the hydrokineticproject was welcomed by the NationalHydropower Association (NHA), whichsaid the decision was a major mile-stone in the development of hydro-electric power in the US.

Water development pledge for AfricaAPLEDGE TO PUSH WATER

development in Africa to boostirrigation and energy has been

issued by governments at a confer-ence on tackling climate change,said the UN Food and AgricultureOrganization (FAO).

The conference brought togetherministers from 53 countries and akey part of the final declaration wassupport for hydro power develop-

ment. They backed clean energy pro-duction and strengthening regionalpower pools.

Strategically, they advocated theimplementation of integrated devel-opment of water, agriculture andenergy programmes to enhance sus-tainable development. Specifically,they also sought accelerated invest-ment in water resources for agricul-ture and energy.

The mid-December conference,held in Libya, noted that Africa waslikely to suffer severely from theimpact of climate change. Concernswere raised especially about thediminishing size of Lake Chad.

The ministers agreed to pushresearch and development of renew-able energy and agriculture as part ofthe measures to mitigate the mostexcessive impacts of climate change.

PPL CORPORATION HAS WITH-DRAWN an application filed ayear ago with the US Federal

Energy Regulatory Commission(FERC) to expand its Holtwood hydro-electric plant on the SusquehannaRiver in Pennsylvania, stating that theproject was no longer economicallyjustifiable.

William H. Spence, executive vicepresident and chief operating officerof PPL Corporation, said the companyhad evaluated the project in light ofcurrent economic conditions and pro-jections of future energy prices, andconcluded that it would not be eco-nomical to pursue the scheme, whose

STUCKY HAS ENTERED INTO Astrategic hydro developmentpact with US firm Doheny

Global Group for projects to be builtin Georgia, central Asia.

At the end of last year, Dohenyannounced it was planning to investup to US$175M in hydro schemes inGeorgia. It anticipates building four tosix plants with combined installed

PPL withdraws application toexpand Holtwood hydro plant

costs had grown to an estimatedUS$440M.

The expansion at Holtwood hadbeen included in PPL's capital budget.Construction was expected to begin in2009, assuming receipt of necessaryapprovals and permits. The expectedin-service date was 2012.

Spence noted that even prior tothe decision to cancel the Holtwoodproject, PPL had reduced plannedcapital spending by more than$200M for 2009 in the face of theworldwide financial crisis and theincreased cost of financing. PPL willcontinue other generation expansionprojects that are already under con-

struction at other facilities.The expansion at Holtwood would

have included construction of two addi-tional hydroelectric turbine-generatorswith a combined capacity of 125MW.The existing Holtwood hydroelectricplant has a generating capacity of108MW and has been operating since1910.

PPL will continue, subject to neces-sary regulatory approvals, with itsplans to transfer certain company-owned lands in Lancaster and Yorkcounties to the Lancaster CountyConservancy as part of a broad public-private initiative to preserve land alongthe Susquehanna River for public use.

Stucky in Georgia hydro pact with Dohenycapacity of at least 100MW.

The Switzerland-based consultant isto work with Doheny on developing therun-of-river projects, and the partiesare liaising with the Ministry of Energy.Doheny said that its hydro power devel-opment plans are strongly backed bythe government of Georgia and the US.

In a statement, Stucky said: 'Thesynergy that will be created by com-

bining the extensive knowledge,expertise and abilities of our two com-panies will allow us to execute signif-icant new projects and demonstratecontinued commitment to Georgia.'

Georgia has said hydro powerdevelopment is an economic priority,and Doheny's plans were announcedfollowing a US trade mission to thecountry in late October.

WORLD NEWS


ONTARIO POWER GENERATION(OPG) and the Lac Seul FirstNation have formed an historic

partnership that will see the FirstNation own 25% of the Lac Seulhydroelectric generating station, locat-ed near Ear Falls, Ontario, Canada.

This is first such partnership forOPG and paves the way forward for anew way of doing business accordingto OPG Chairman Jake Epp. '[We've]made history. OPG will use thisapproach to develop similar projectswith other First Nations and we've cre-ated a new way of growing our busi-ness. We're moving towards a future

EVN HAS ENTERED INTO A JOINTventure with Statkraft to developa hydro power scheme on the

Devoll River in Albania.The move comes almost a year after

EVN entered exclusive negotiations tobuild three peak-power plants on theriver. The Austrian utility had won aninternational tender competition thatwas launched after it had earlier sub-mitted an unsolicited proposal to devel-op hydro power resources on theDevoll River.

Concession negotiations have beenunderway for most of this year andhave been concluded with Statkraftnow involved in the venture.

The plants were initially conceivedwith a combined capacity of 400MWbut are now planned to be 340MW intotal. The hydro power scheme has adevelopment budget of Euro950M(US$1.33B), and construction periodof approximately eight years.

Owned equally by EVN and theNorwegian utility, the JV will see thembuild on their respective experience inthe region and use their combined

ALUMINIUM PRODUCER ALCOAhas struck a new power supplyagreement with Hydro-Quebec

through to 2040.The deal follows a Memorandum

of Understanding (MoU) signed earli-er this year with the provincial gov-ernment. Under the arrangement,there would be agreement for addi-tional power as well as renewal ofexisting supply contracts.

Alcoa said the deals would cover

ACONSORTIUM LED BY ALSTOMHydro, and including VoithSiemens and Andritz Hydro, has

been awarded a major equipmentsupply contract for a share ofthe 3300MW Jirau project underconstruction in the state ofRondonia, Brazil.

A total of 28 bulb turbine-genera-tors, each 75MW capacity, are to besupplied by the consortium. The plantwill have 44 units when completed,and the first units are to be commis-sioned from 2012.

Alstom Hydro said its contractwas worth more that Euro300M(US$420M), and was awarded by theGDF Suez-led project developer. It isto supply 10 turbines, 17 generatorsand all of the associated governorsfor the 28 units.

The project developer, known asEnergia Sustentavel do Brasil, is led byGDF Suez (50.1%) and includes Chesf(20%), Eletrosul (20%) and CamargoCorrea (9.9%).

A few months ago, Alstom Hydroannounced separately the value of

OPG and First Nation in energy partnershipwhere development of clean, renew-able hydroelectric projects proceedsin way that is fair to all parties and isbased on trust and respect,' he said.

'This is a proud time for my people,and myself,' added Chief Clifford Bullof the Lac Seul First Nation. 'It marksthe end of an era when our rights andour history were ignored and launchesan era where we're treated as equals.'

George Smitherman, Deputy Premierand Minister of Energy andInfrastructure, agreed that the partner-ship is a significant step forward toensuring Ontario's First Nations can fullyparticipate in responsibly developing the

province's shared resources. 'In addi-tion to providing clean, green power forour province, this new generating sta-tion will benefit the Lac Seul First Nationthrough revenues that will help toenhance the future sustainability of theircommunity,' Smitherman noted. 'I lookforward to a future where First Nationspartnerships with energy generators areconsidered the norm and not historic.'

The partnership stemmed from apast grievance settlement reached in2006. The settlement addressed theimpact of hydroelectric facilities thatwere built on traditional lands of the LacSeul First Nation on the English River

system between 1930 and 1948.The equity partnership will see the

Lac Seul First Nation purchase a 25%share of the 12.5MW station, whichwill be in service early this year. Thestation will generate enough electrici-ty to meet the annual needs of 5000homes. All future profits and risks willbe shared by OPG and the First Nation.

The new station, adjacent to the EarFalls Generating Station, will have dualnames, also being known by theOjibway title ObishikokaangWaasiganikewigamig, which translatesas White Pine Narrows electricity gen-erating building.

Jirau contract for Alstom,Voith and Andritz

its contract to supply electro-mechanical equipment and hydro-mechanical equipment on Jirau'ssister project – the 3150MW SantoAntonio project on the 6450MWMadeira scheme under constructionin western Brazil.

The contract is worth approximate-ly Euro500M (US$700M). The con-cessionaire joint venture is led byOdebrecht, which awarded the engi-neering, procurement and construction(EPC) contract. Alstom Hydro is amember of the concession JV and pre-viously said it would supply 19 turbinesand 22 generators to the SantoAntonio project which, like Jirau, willhave 44 units.

Alstom Hydro is a JV of French com-panies Alstom and Bouygues.

Separately, Andritz announced theaward of a contract to supply a shareof the bulb turbine-generators andother equipment for Santo Antonio. Itsaid the contract was valued atapproximately Euro250M (US$350M)and would see it supply 12 units plus24 voltage regulating systems.

Statkraft teams withEVN for Albania venture

knowledge in the planning, construc-tion and operation of the scheme. Theutilities noted that the Devoll initiativeis one of Europe's largest hydroschemes at present.

The Devoll scheme follows anenergy development pact signed nearlytwo years ago by the Government ofAlbania, the federal province of LowerAustria, and EVN. Feasibility studieswere undertaken in 2007. The schemewill boost the country's hydro produc-tion by about a fifth.

About three months ago EVN andanother Austrian utility, Verbund, wereawarded a concession to build the48MW Ashta project in Albania. The JVhas a 35-year concession, includingthe construction period to 2012, andthe Straflo Matrix units are being sup-plied by Andritz for the project.

Almost a year ago Statkraft signeda deal to help develop four hydro powerplants in Bosnia and Herzegovina. Theplants are to be built on the lowerVrbas river in the Republic of Srpska,and are expected to have a combinedinstalled capacity of 75MW.

Alcoa and Hydro-Quebec in power agreement dealsupplies for its three smelters in theCanadian province and provided for theupgrade and expansion of one facility.In total, the power supply agreementsare for just over a quarter of the com-pany's aluminium production.

The agreements cover approxi-mately 1.1M tonne/year, and the threesmelters (Baie Comeau, Becancourand Deschambault) are to be suppliedwith a total of 2.1GW through to theend of 2040. The capacity of the Baie

Comeau smelter is to be expanded by111,000 tonne/year by 2014 andhave greenhouse gas (GHG) emissionscut by 40%.

In recent months, Alcoa has sepa-rately signed power supply deals forsmelters in Washington state. It madean agreement with Bonneville PowerAdministration (BPA) for the Intalcosmelter, and Chelan County PublicUtility District (PUD) for its Wenatcheesmelter. Under the BPA deal, up to an

average of 240MW is to be providedfor the first 10 years of the contract,which is scheduled to commence inOctober 2011. For a further sevenyears the utility would supply 160MW.

Last year, the company's progresswith plans for a 340, 000tonne/year smelter in Iceland led toNorsk Hydro bowing out with its ownconcept. It already has supplies fromthe recently built Karahnjukar hydro-electric plant.

WORLD NEWS


In BriefA GRANT OF US$12.5Mhas been approved by theInter-AmericanDevelopment Bank(IADB) to refurbish thePeligre hydro power plantin Haiti. Output from the54MW plant is half of itspotential due to the age ofthe equipment and reser-voir sedimentationreducing the volume ofwater available for hydropower. IADB said that thegrant was for the firstphase of a US$40Mrehabilitation programme.The five-year long rehabil-itation programme will bein three phases – one foreach of the plant's threeturbines. The followingtwo phases are to be fundedby IADB and the OPECFund for InternationalDevelopment.

ENEL HAS SET UP ENELGreen Power to hold itshydro and other assets inthe group's renewablesportfolio and to developfurther resources, includ-ing run-of-river projects inEurope and the Americas.The new unit has morethan 270 mini-hydroplants in Italy, and theircombined installed capaci-ty is 1507MW. Elsewhere,the unit has approximately1GW of hydro powerassets. Its strategy is toboth increase efficiency atexisting plants and tofocus on run-of-riverdevelopments. OutsideItaly, breakdown of thehydro power assets is26MW in Spain, 314MWin North America and640MW in Latin America.At present, Enel GreenPower has almost 4.3GWof installed capacitygenerating more than17TWh.

SN Power reviews health andsafety at Allain DuhanganNORWEGIAN HYDRO DEVELOP-

ER SN Power is reviewing thehealth and safety data on the

Allain Duhangan project under con-struction in India after learning ofunder-reporting of fatal accidents.

The company said that it hadlearned of two fatalities among sub-contractors that were not reported atits partly-owned project being built inthe state of Himachal Pradesh.

It added that the total number ofdeaths on the run-of-river project is 11since construction began in 2006, and

ADEAL BETWEEN AVISTA ANDthe Coeur d'Alene Tribe hastaken forward the US utility's

relicensing efforts for its plants onthe Spokane River, which runsthrough Washington and Idahostates.

Under the comprehensive settle-ment that covers past and future useof tribal land and water for theSpokane River plants, the utility andtribe have also agreed to the reli-censing bids for 50-year terms, main-taining water levels, transmissionline corridors and future storage pay-ments related to Post Falls reservoir.

An investment package worth upto US$150M is planned for environ-mental measures at Coeur d'AleneLake and compensation to the tribe.The level of compensation for pastuse of storage water is US$39M,and payments are to be made overthree years.

For future storage the partiesagreed to compensation of US$0.4Mannually for the first 20 years of anew licence, and US$0.7M each yearfor the remainder of the term.

In addition, Avista has agreed toestablish a resource protection trustfund to help it and the tribe collabo-rate on erosion control, wetlandmanagement, monitoring, weed man-agement and protection of culturalresources. Funding of US$100M willbe contributed by the utility over theterm of the 50-year licence.• Want to read more news? Why notsign up for our email newsletter atwww.waterpowermagazine.com.

THE ENERGY SECTOR OF THEKyrgyz Republic is continuing tosuffer poor hydrology and knock-

on impacts, which have brought finan-cial help from multilateral agencies,but in bilateral talks its Governmenthas agreed with Iran to expand co-operation in dam construction.

The World Bank said that the hydropower-dependent Central Asian coun-try was experiencing a dry hydrologicalcycle made worse by a severe winter,resulting in uncertain power productionfrom its generating assets.

There are 3.4GW of hydro assets inthe country, and the portfolio is domi-nated by the Naryn cascade which isregulated by the Toktogul reservoir.

A key step for the Bank is to supportthe thermal power plants at Bishkekand Osh, which supply power as wellas heat to major cities but are down in

NAMIBIA POWER IS FINALISINGan MoU for mini-hydro develop-ment on the Orange River and

has launched studies for the devel-opment of the Baynes hydroelectricpower project.

The state utility is finalising a MoUwith South Africa-based ClarksonPower, which has already conductedmost of the studies for the project.Under the deal, the companies wouldjointly develop mini-hydro plants alongthe Orange River.

NamPower has board approval tocontribute N$7.2M (US$700,000)

there have been 81 personal injuriesrequiring treatment at hospital or anout-patient clinic.

The 192MW hydro power project isbeing developed by the joint venturecompany Malana Power, in which SNPower has a 43% stake. The principalshareholder is NLJ Bhilwara Group(45%) and the balance is owned by theInternational Finance Corporation (IFC).

The underreporting of fatalitiesemerged from an audit in mid-November. SN Power said it had notbeen given full and complete informa-

tion from the project company.Allain Duhangan has an under-

ground powerhouse at the confluenceof the Allain and Duhangan rivers,which are tributaries of the Beas river.The design head is 833m and thepowerhouse holds two 96MW verticalaxis Pelton turbines. The projectbudget is US$220M.

SN Power is equally ownedby Statkraft and Norfund, an invest-ment body.

There is agreement in place for theutility to raise its holding to 60%.

Kyrgyz Republic suffers weakhydrology, gets funding boost

production capacity from 700MW to200MW. Funds of US$11M have beenprovided under an emergency assis-tance project to finance equipment,material and spare parts for the plantswith the work expected to take almosta year and a half to complete.

Further funding has been given bythe International Monetary Fund (IMF)- which also noted the drop in hydropower output - to help the countrytackle the same as well as more wide-spread energy and economic prob-lems. Over 18 months the IMF will giveabout US$100M.

However, despite the ongoing hydro-logical difficulties, earlier this monththe bilateral talks between the Kyrgyzand Iranian governments highlighted anumber of areas of proposed eco-nomic and infrastructure co-operation,including dam construction.

Avista progresson relicensingSpokane plants

Namibia Power moves onOrange River, studies Baynes

towards the cost of the feasibilitystudy.

Separately, the utility has launchedenvironmental and techno-economicfeasibility studies for the Baynes hydropower scheme, which is a joint initia-tive of the governments of Namibiaand Angola. The studies are expectedto take about 18 months.

The project, on the Kunene river inAngola, was previously estimated tohave a potential installed capacity of360MW. The Angolan side of the devel-opment is being handled by power util-ity ENE.

WORLD NEWS


Brookfield applies to LIHIBROOKFIELD RENEWABLE POWER has applied for certification for itsTwin Cities plant, in Minnesota, to the US Low Impact HydropowerInstitute (LIHI).Brookfield closed its acquisition of the 17.9MW plant in 2008 afteragreeing a deal with the previous owner, Ford Motor Co, in mid-2007. Itgenerates approximately 97GWh of electricity annually.The plant, on the Mississippi river, holds four Francis turbines in thepowerhouse that is integral with a US Corps of Engineers dam, whichconsists of twin lock chambers and a central concrete spillway. It isoperated in run-of-river mode.LIHI said no further works were planned at the plant. Brookfield has plansfor another plant downstream of Twin Cities, and it is expected to have aninstalled capacity of 10MW.Deadline for comment to LIHI on the application was 30 January 2009.The company's Black River scheme was certified previously by LIHI, whichhas noted that Brookfield is its most active client.Separately, in October 2008, LIHI re-certified Hydro Energy DevelopmentCorp's Black Creek plant, near Seattle, Washington state. The plant hasan installed capacity of 3.7MW and average annual generation is 10GWh.

THE 14GW ITAIPU PLANT ON THEborder of Brazil and Paraguaylast year produced its highest

ever annual output, reported thebinational plant operator.

Itaipu generated almost94,685GWh of electricity in 2008,which is 1.3% higher than the previ-ous highest output, achieved in2000. However, the plant had 20generating units installed last yearto take advantage of good hydrologyon the Parana river compared to only18 units in 2000.

Itaipu operated with 18 unitsbetween it commencing operations in

Itaipu output highest ever in 20081991 to the third quarter of 2006when the 19th turbine-generator wasinstalled. The last unit was added inmid-2007. Typically, the plant is oper-ated with all but two of the 715MW ver-tical Francis units running.

Output in recent years was averag-ing about 90,000GWh, rising from2006 and the plant operator nowexpects production to be able to aver-age approximately 95,000GWh.

The output last year delivered a 19%share in the Brazilian market, whichwas no change on 2007. However, theshare is down on the 26% shareenjoyed in 1995 and 1996, shortly

after the plant became operational. In2000 Itaipu held a quarter of theBrazilian market.

In the third quarter last year, Brazillooked to further binational co-opera-tion through a pact with Argentina toinvestigate additional hydroelectricschemes on the Uruguai river in theborder region, especially for the Garabischeme.

Also on the Parana river in the1990s, Argentina developed the3200MW Yacyreta project withParaguay. Argentina also has a bina-tional project with Uruguay – the1890MW Salto Grande scheme.

In BriefAT THE END OF 2008,Scottish and SouthernEnergy (SSE) generatedfirst power over 24 hoursin commissioning work atthe 100MW Glendoeplant in Scotland – thebiggest conventionalhydro power project to bebuilt in the UK for half acentury. Constructionwork began on site beganalmost three years ago.The project is being builtby the Hochtief GlendoeJV, a joint venture led byHochtief. The designer isPoyry Energy and genera-tion plant is supplied byAndritz Hydro.

A WAVE ENERGYdevelopment deal has beensigned by Ocean PowerTechnologies and theLeighton constructiongroup to build plants offthe coast of Australia. Thepartners are to identifyand assess potential sitesfor wave energy projectsoff the east and south costsof Australia. The pact hasbeen signed by subsidiariesof the businesses - OceanPower Technologies(Australasia) and LeightonContractors.

GDF SUEZ HAS COM-PLETED the mainconstruction work for SaoSalvador hydro powerproject in northern Brazil.The project has been builton the river Tocantins, onthe border of the states ofTocantins and Goias. Lastyear Brazilian nationalenvironmental regulator,Ibama, issued its approvalfor the 241MW plant tobe operated. The plant isdue to be operational from2011. Ibama said thelicence to begin operationswas valid for four years.

US COMPANY SYMBIOTICSEnergy has submitted furtherdevelopment plans for the

700MW North Eden pumped storageproject in Utah to the Federal EnergyRegulatory Commission (FERC).

Symbiotics received a preliminarypermit for the project from FERC in lateDecember. It is developing the projectthrough North Eden Hydro LLC, whichhas submitted a notification of intent(NoI) and pre-application document(PAD).

The preliminary permit covers stud-ies for a potential pumped storage proj-ect in North Eden Canyon off BearLake in Rich County, Utah, close to theborder with Idaho.

Work on the PAD began in the thirdquarter of 2007.

It is envisaged that the project willhave two dams and reservoirs plus asurface powerhouse fitted with seven100MW pump turbines, a surface pen-stock and tailrace tunnel. The devel-oper aims to produce approximately2027GWh annually from the plant.

Company spokesman Justin Barkertold IWP&DC that a conservative devel-opment budget of approximatelyUS$700M has been set for the proj-ect, which it is hoped will become oper-ational around 2011-12. He said thetiming was related to the constructionof the Gateway West transmission linkto which the project would connect.

Symbiotics' earlier attempt to devel-op a hydro power project at Bear Lake– in Hook Canyon – was a 1120MWscheme covering territory over Utahand Idaho but was dropped due toopposition.

IBAMA, THE BRAZILIAN ENVIRON-MENTAL regulator, has fined thebuilder of the 3150MW Santo

Antonio project over fish fatalitiescaused by construction-related work.

The agency found 11 tonnes of fishkilled by the construction-related workon the river Madeira, in the westernstate of Rondonia. A fine of US$7.7Mwas set against the builder, MadeiraEnergia Consortium (Mesa).

Ibama said that the fine was calcu-lated from one law which sets a valueof US$500 per kilo of fish killed, whichbrought the basic cost to US$5.5M.However, the sum was increasedthrough allowance in another law,which resulted in the fine beingincreased by 40%.

Costs incurred by the builder willalso include remedial works to count-er the damage caused to fisheries.

Fish fatalities fine at Brazil'sSanto Antonio hydro project

The fine follows a site visit to theproject on 10 December 2008 by thestate representative of Ibama. Theteam gave technical guidance on help-ing to minimise fisheries impacts.

Santo Antonio is being constructedon the Madeira rapids, approximately6km upstream of Porto Velho and Vilade Abuna on the Brazilian and Bolivianborders, respectively.

Mesa is a consortium led byBrazilian electricity utility Furnas andconstruction group Odebrecht. The JVwas awarded a 30-year concession tobuild, operate, manage and market theoutput of the hydro project at the endof 2007.

Construction work on Santo Antoniostarted in the third quarter of 2008.The plant will have 44 units and firstpower is scheduled to be produced inthe third quarter of 2012.

Symbioticssubmits NorthEden plans


DIARY

Let IWP&DC’s readers know about your forthcoming conferences and events.For publication in a future issue, send your diary dates to: Carrieann Stocks, IWP&DC, Progressive Media Markets Ltd, Progressive House,

2 Maidstone Road, Foots Cray, Sidcup, Kent, DA14 5HZ, UK. Alternatively, email: [email protected].

DIARY OF EVENTS

May

13-15 MaySecond National Symposium onDam SafetyEskisehir, Turkey

CONTACT: Eskisehir OsmangaziUniversity, Earthquake ResearchCenter, 26480 Bah Meselik,Eskishehir, Turkey.Email: [email protected];[email protected].

17-21 MayWorld Environmental & WaterResources CongressKansas City, Missouri, US

CONTACT: Adele C. Dicken,CMP, Conference Manager, ASCEWorld Headquarters, 1801Alexander Bell Drive, Reston,Virginia 20191-4400, US.Email: [email protected].

24-29 May23rd ICOLD CongressBrasilia

CONTACT: Brazilian Committeeon Dams, Rua Real Grandeza 219,Bloco C S/1007 Botafogo, Rio deJaniero, Brazil.Tel: (055 21) 25285320.Fax: (055 21) 25285959.www.cbdb.org.br.

June

24-26 JuneIHA Congress 2009Reykjavik, Iceland

CONTACT: InternationalHydropower Association, FifthFloor West, Nine Sutton CourtRoad, Sutton, Surrey. UnitedKingdom, SM1 4SZ.Tel: +44 20 8652 5290.Fax: +44 20 8770 1744.Email: [email protected].

April

20-22 April2nd Int. Conference on Hydro-power Technology & EquipmentBeijing, China

CONTACT: Wang Yu, Lei Dingyan,Sun Zhuo, Rm. 431, Main Building,No.1 Lane 2 Baiguang Rd. XuanwuDist, Bejing 100761, China.Tel: 86 10 63414390; 63414391;63414394.Fax: 86 10 63547632.E-mail:[email protected]/ichte/en/index.jsp.

28-29 AprilSmall Hydro 2009Vancouver, Canada

CONTACT: Carrieann Stocks,Editor, International Water Power& Dam Construction, 2 MaidstoneRoad, Foots Cray, Sidcup, KentDA14 5HZ, UK.Tel: +44 (0) 208 269 7777.Fax: +44 208 269 [email protected]/smallhydro2009.

February

8-10 February

Middle East Electricity 2009Dubai, United Arab Emirates

CONTACT: IIR Middle East,Dubai, United Arab Emirates.Tel: 971 4 407 2422.www.middleeastelectricity.com.

25-27 FebruaryGeosynthetics 2009Utah, US

CONTACT: Industrial FabricsAssociation International (IFAI)Geosynthetic Materials Association(GMA), 1801 County Road B WRoseville, MN 55114-4061 US.Tel: +1 651 222 2508.Fax: +1 651 631 9334.www.geoshow.info.

March

3-5 MarchUnderwater Intervention 2009New Orleans, US

CONTACT: Rebecca Roberts,5206 FM 1960 West, Suite 202,Houston, TX 77069 US.Tel: +1 281 893 8539.Email: [email protected].

10-12 MarchRenewable Energy WorldConference & ExpoLas Vegas, US

CONTACT: Jan Simpson,Conference Manager.Tel: +1 918 831 9736.Fax: +1 918 831 [email protected].

12-13 MarchWater Power & Climate Change –Annual Conference on HydraulicEngineeringDresden, Germany

CONTACT: Prof Dr-Ing habil R.Pohl, Institut Fur Wasserbau undTechnische Hydromechanik,Technische Universitat Dresden, D-01602 Dresden, Germany.Tel: +49 351 463 33837.

Fax: +49 351 463 [email protected].

16-22 March5th World Water ForumIstanbul, Turkey

CONTACT: 5th Forum Secretariat,DSI, Libadiye Caddesi No.54,Küçükçamlica - Üsküdar, 34696Istanbul, Turkey.Tel: +90 216 325 49 92.Fax: +90 216 428 09 [email protected].

30-31 MarchArabian Power & Water Summit2009Abu Dhabi, United Arab Emirates

CONTACT: Middle East BusinessIntelligence, Dubai Media City, POBox 25960, Al Thuraya Tower 1,20th Floor, Dubai, United ArabEmirates.Fax: +971 4 368 8025.www.meed.com.

July

27-30 JulyWaterpower XVISpokane, Washington, US

CONTACT: HCI Publications,410 Archibald Street, Kansas City,

October

27 September – 1 OctoberDam Safety 2009Florida, US

CONTACT: Association of StateDam Safety Officials (ASDSO),450 Old Vine Street, LexingtonKY 40507, US.Tel: +1 859 257 5140.Fax: +1 859 323 1958.Email: [email protected]://www.damsafety.org.

3-8 OctoberCanadian Dam AssociationAnnual ConferenceBritish Columbia, Canada

CONTACT: Canadian DamAssociation, PO Box 4490, SouthEdmonton Postal Station,Edmonton, Alberta, Canada T6E4X7.Tel: +1 780 432 7236.http://www.cda.ca.

26-28 OctoberHydro 2009Lyon, France

CONTACT: Hydropower &Dams Editorial Office,Aqua~Media International Ltd,123 Westmead Road, Sutton,Surrey SM1 4JH, UK.Tel: +44 20 8643 [email protected].

August

10-14 AugustInternational Association ofHydraulic Engineering & Research33rd Biennial CongressVancouver, BC, Canada

CONTACT: Stacey Ann P.Gardiner, CMP, CongressManager, ASCE WorldHeadquarters, 1801 AlexanderBell Drive, Reston, Virginia 20191-4400, [email protected]

MO 64111, US.Tel: +1 816 931 1311.Fax: +1 816 931-2015.Email: [email protected].

The IHA Congress takes place on 23-26 June 2009 in Reykjavik, Iceland.Contact us today to find out more about this extraordinary event.

Tel: +44 20 8652 5290 Email: [email protected] www.hydropower.org

Advancing Sustainable Hydropower


INSIGHT

HYDRO power is back. And it’sback in a big way in Scotland.These were the words of ScottishFirst Minister Alex Salmond fol-

lowing publication of the ScottishHydropower Resource Study in September2008. Energy Minister Jim Mather echoedhis colleague’s sentiments. ‘We are desper-ately enthusiastic about hydro,’ he said.

So how did this hydro study prompt suchan accolade from the Scottish government?As David Williams, chief executive of theBritish Hydropower Association admitted,hydro power has long been the ‘quiet’renewable. The success behind this study is

that it has proved the vital role which hydrocan play in the Scottish drive for renewableenergy generation. Furthermore, Williamsbelieves that the study will stimulate devel-opment of new projects of all sizes, in acountry which has already firmly embracedhydro technology.

HUGE IMPORTANCE

The Scottish Hydropower Resource Studywas carried out for the Forum forRenewable Energy Development in Scotland(FREDS). A partnership between industry,academia and government, FREDS has a

role to play in helping Scotland meet its2020 target of generating 50% of electricityfrom renewables. Prior to this in 2011, amilestone target has also been set at 31% –equivalent to approximately 5GW ofinstalled capacity.

As Energy Minister Jim Mather said, theserenewables targets will enable the govern-ment to capitalise on the country’s hugerenewable energy resource, securing signifi-cant economic development. ‘In makingScotland the green energy capital of Europe,we want to utilise the rich mix of our diverserenewables potential,’ he stated. ‘Hydroremains a hugely important part of that mix.’

A welcome return for hydroThe Scottish government is working hard to claim the title as the green energycapital of Europe. In recent years the pace of hydroelectric development has slowed,but publication of a new study has established hydro’s important role in fulfilling thisambition. There is now tremendous enthusiasm to ensure that Scotland’s hydropower legacy lives on. Suzanne Pritchard reports

very quiet in recent years. Aside from themarket, the study showed that the cost oflicences is less influential than might havebeen thought, while planning restrictions inenvironmentally sensitive areas have a verystrong reducing effect on the national total.’

The study strongly recommends that pro-cedural change is worthy of immediateattention and states: ‘It is now evident thatfactors such as natural heritage designationsand business rates will dictate how much ofa contribution hydro power will make inpractice. Therefore, there is justification toscrutinise the hydro planning process forunnecessary delays and restrictions, partic-ularly where the impacts are weaker anddefensible with simple mitigation measures,without sacrificing an appropriate level ofenvironmental conservation.’

The areas highlighted as being in need offurther research include:• The effect of natural heritage land desig-

nations upon the success rate and size ofhydro schemes.

• Inter-catchment diversions.• The impact of offsetting local consumption.• A detailed survey of existing weirs across

Scotland.

INSIGHT


With the above thought in mind, thehydro resource study was commissioned toprovide an assessment of potential hydropower development within Scotland. It wasalso to provide an estimate of the theoreti-cal potential for expanding hydro. All ofthis, Mather added, would help to ensurethat this form of energy continues to con-tribute to Scotland’s renewables targets.

‘One reason why we set up the study wasto emphasise and give confidence to peoplethat hydro still has a big part to play,’ FirstMinister Alex Salmond said. ‘The reportindicates that small scale hydro projectstaken together could light up to a quarter ofScottish homes. What is so exciting is thatthese small and micro hydro projects couldcommit half as much again of the enormouscontribution that hydro already makes inthis country. We can say that hydro is backin a big way in Scotland.’

Installed hydroelectric capacity inScotland stands at 1379MW. The study hasshown that there are still 657MW of finan-cially viable hydro schemes to exploit. Usingexpected load factors of 40% for run-of-river schemes and close to 100% for storageschemes, the total number of additionalhomes that could be powered by hydroelec-tricity is close to 600,000. The equivalentoutput would be 2.98TWh/yr. However,grid and environmental constraints meanthat only some of this could be connected.

‘This study has shown that the availableand economical hydro resource in Scotlandcan play a significant role in reaching ourrenewable energy targets,’ Mather said. ‘Weare keen to get a better alignment betweencommunities, statutory bodies and develop-ers. This report will help us to do that.’

REMOVING BARRIERS

Co-author of the study, Nick Forrest,explained that its purpose was not just toquantify the remaining potential for hydroin Scotland, but to identify the main barri-ers to development. ‘Our approach to modelhydro schemes remotely, using a geograph-ical information system called Hydrobot [seep42], allowed us to examine how the totalpotential varied in response to key factors,’he said. ‘It takes months to analyse thewhole of Scotland, but with the Hydrobotmodel it can be repeated as often as you likein a fraction of the time.’

‘There are many issues which peopleregard as holding up the hydro developmentprocess,’ Forrest said. ‘Unsurprisingly,market factors such as the cost of electricityare a fundamental influence – this is onereason why hydro development has been

Hydro studiesThe Scottish Hydropower Resource Study wascarried out on behalf of the Scottish governmentto assist the hydro sub group for the Forum forRenewable Energy Development in Scotland(FREDS). It was carried out by Nick ForrestAssociates in close co-operation with theScottish Institute of Sustainable Technology andBlack & Veatch. It was funded by thegovernment’s renewables policy team.

The Scottish Hydropower Resource Study isavailable online at:http://www.scotland.gov.uk/Topics/Business-Industry/Energy/19185/FREDSHydroResStudy

Table 1: Total and financially viable potential hydropower schemes in Scotland,using HydroBot’s baseline scenario (source: Scottish Hydropower Resource Study 2008)

Total number Total potential Total potential annual Financially Financially viable Financially viable annual New damsof schemes power (kW) energy (MWh) viable schemes power (KW) energy (MWh)

36,252 2,593,317 10,644,403 1019 657,259 2,766,682 128

Full stream ahead forsmall hydroSmall hydro is the way ahead for the future,according to Iain Wotherspoon, head of GreenHighland, a specialist in small scale hydroschemes. He says that the advantages are soattractive that there are now a total of sevenseparate small hydro schemes being proposedin Glenlyon, in the heart of Perthshire, Scotland.

Wotherspoon inherited a 1930s hydro schemewhen he bought Glenlyon House five years ago.The scheme has a miniature dam high abovethe valley and a 2.4km iron pipe leading to asmall generator house. The scheme is hardlynoticeable in the impressive Highland sceneryand has no impact on the River Lyon.Wotherspoon put in a modern system, assumingthat the scheme would pay for itself within fiveyears. In fact, the new 900kW system costaround £750,000 (US$1.1M) but the paybackperiod was only three years and the schemenow earns revenue of around £300,000(US$447,000) a year in sales of power toScottish and Southern Electricity.

After experiencing first hand how beneficialrenewable energy technology can be,Wotherspoon set up his own renewable energycompany in early 2008. Caledon Green is aspecialist in renewable energy for the landmanagement and property sectors, and GreenHighland is the subsidiary now working topromote small scale hydro in Scotland.

For more information log ontowww.greenhighland.co.uk

As IWP&DC went to press the Scottishgovernment announced the go ahead for twomore Scottish hydro schemes:

The 3.5MW Black Rock scheme is located nearEvanton in Ross-shire and was proposed by RWENpower in December 2006.

The 2.5MW scheme on the Allt Coire Chaorach,near Crianlarich was proposed in March 2007 byScottish and Southern Energy.

The two new projects will be capable of providingpower for over 3500 homes.The new study was commissioned to provide an

assessment of potential hydro power in Scotland


INSIGHT

‘Previously,’ Forrest added, ‘it may havebeen hard to justify spending time andresources changing the planning frameworkwhen the benefits are unclear. We are hope-ful now that the results of the study willencourage local and central government tofurther improve the planning process.’

Steps have already been taken in the rightdirection. The Scottish government has com-mitted to process planning applicationswithin nine months where there is no needfor a public enquiry. ‘However,’ Forrest cau-tioned, ‘we hope that the nine month targetwill not be achieved by simply shifting thepoint at which an application is declared“received”, rather than speeding up theplanner’s own processes.’

Energy Minister Jim Mather added thatthe FREDS hydro sub group is looking atfurther opportunities and barriers facingthe sector. It will be making recommenda-tions to the Scottish government within the

early part of this year. Forrest hopes thatthese will include one important recom-mendation to ensure the future success ofnew hydro development. ‘We must pressthe government to develop a transmissionand distribution network that can handlethe renewable energy that Scotland is readyto produce,’ he said.

ECONOMIC GROWTH

From recent calculations it appears, helpedby hydro, that Scotland is more than readyto meet its renewable energy targets. ‘I cansafely say that our first ambitious renew-ables target will be met,’ First Minister AlexSalmond said recently.

Thirty six renewable project applica-tions, totalling 2.5GW, are currently beforethe Scottish government’s energy consentsunit. Nine of these are for a total of 25MWof hydro.

Current installed renewables capacity inScotland totals 2.8GW. Most consentedprojects will be operating by 2011, and withtime for more projects to still come forward,the government is confident it will be wellon course to meet the target of 5GW.

Scotland’s First Minister has his eye on thefuture. ‘The legacy of Scottish hydro willextend into the future,’ he said. ‘There mightbe ten times as many hydro projects comingthrough in the next few years.’

Referring to the 100MW Glendoe projectscheduled to be open in spring 2009, theEnergy Minister said that, although this willmake a magnificent contribution toScotland’s renewables capacity, ‘we areunlikely to see much in the way of furtherlarge scale hydro development’.

‘But there is huge untapped potentialand a sustainable and profitable future insmaller and micro hydro schemes,’ he said.‘Each scheme would have to be assessed onits own merits, but if we can turn the tapon to new hydro power we can tackleclimate change and continue to stimulateeconomic growth.’

Economic growth is also on NickForrest’s mind in the current financial cli-mate. ‘This report should offer comfort tothe construction industry whose reducedworkload in the housing sector may beslightly offset by an increase in the renew-ables industry,’ he said. ‘With over 1000financially viable hydro schemes in thesmall bracket (up to 5MW), there is a lotof potential.’

HYDRO LEGACY LIVES ON

Scotland’s hydro heyday can be traced backto the 1950s and 1960s. Over 50 years laterits future has never looked brighter. Scotland’shydro power legacy is set to live on. As thecountry’s First Minister said: ‘I think hydropower is the most successful form of powergeneration in Scottish history.’ IWP& DC

Scotland has huge untapped potential for small andmicro hydro schemes, although there is unlikely tobe further large hydro development

INSIGHT

ALSTOM has chosen India toestablish its first research anddevelopment centre outsideEurope and it has good reasons.

With a total installed capacity of more than36,000MW, and an estimated untappedpotential of over 130,000MW for hydropower, India is one of the biggest actual andpotential markets in Asia.

Philippe Cochet, president of AlstomHydro, a joint venture between Alstom andBouygues, has said that, ‘by focusing on thespecific issues of the Indian hydro market,the new centre will enable the company todevelop highly innovative [and] integratedproducts and technologies’.

The company has established a technolo-gy centre with 11 engineers (and increasing)at Alstom’s factory in the western Indiantown of Vadodara, in the western Indianstate of Gujurat, and houses a test labora-tory for a scale model of a Pelton ring.

Though most of the Indian hydro powerplants use Francis turbines, where head fallis between 50m and 400m, experts say thatPelton turbines could play an importantrole in the future of the Indian hydropower industry.

The Himalayas are the source of manyperennial rivers that carry huge quantities ofwater across the sub-continent and at manyplaces provide an opportunity of harnessinga head fall of more than 400m, an ideal set-ting for a Pelton turbine.

‘To achieve a stabilised national grid,which unfortunately India does not have, itis important to harness maximum power ata single point through big hydro projects,’says Shivendra Nath Verma, chief engineerof India’s National Hydro PowerCorporation (NHPC).

In India there is a wide variation in thepeak and off-peak demand of electricity,leading to major frequency fluctuations inthe grid. This requires power plants to beshut down and restarted at short notice offive to 10 minutes, and the Indian govern-ment thinks the best way to check these fluc-tuations is through the control of big hydropower plants.

NHPC, a government company operating13 projects totalling 5175MW – with a fur-ther 11 plants under construction expectedto add 4622MW – also happens to be thebiggest customer of hydro power equip-ments in the country. Its largest project – the2000MW Subansiri Lower hydroelectricpower plant in the north-eastern states ofAssam and Arunachal Pradesh – has Alstomturbines, generators, digital governingsystem and main inlet valve.

In the central and southern regions of thecountry, small hydro projects – 5 to 25 MWgeneration capacity – use Kaplan turbines,while on the slow moving rivers power isgenerated through bulb turbines.

Experts say that hydro powercould get a huge push if Indianpolicy makers allocateresources based on puremerit and without politi-cal interference. Asenior government offi-cial related to thehydro power industrytold IWP&DC that inthe past an undueemphasis has been givento thermal power plantsbecause leaders want the


investment to go into their political con-stituencies and produce results within thefive-year term of their office. Most hydropower projects have a longer gestationperiod and their locations are restricted dueto geographical reasons.

Things are not easy for private investorseither. Dr Rajeshwer Prasad Saini, AssociateProfessor at the Alternate Hydro EnergyCentre of Indian Institute of TechnologyRoorkee, said that the Himalayan foothillstate of Uttarakhand holds a huge potentialof hydro but due to the lack of clear policyand related laws, there is uncertainty andprivate investors are reluctant to come for-ward. ‘Hydro projects last for 30-40 years,but there is no provision for an increase inthe price for generated power that is boughtby state governments at INDRupees 2(US$0.04 cents) to INDRupees 3 (US$0.06cents) per KW-hour’, he said.

Private investors are also reluctant toinvest in a hydro project when they are inremote locations and therefore require extrafunds to build supporting infrastructure,such as link roads and the long transmissionnetwork connecting the grid.

Furthermore, Himalayan rivers such asthe Ganges, Yamuna and Indus contain hugequantities of mud and sand which leads toearly corrosion of turbines blades, whichcauses frequent operational problems. Thecomposition of this silt is different at differ-ent places, thus requiring specific measuresto deal with the problem, depending on thelocation of a plant.

At its Vadodara centre, Alstom has estab-lished a silt abrasion test-rig laboratory tocarry out research on new technical solu-tions to this problem.

Presently it is testing the resistance of thespecialist soft coating Neyrco and the HighVelocity Oxy-Fuel (HVOF) spray coating todeal with the silt collected from variousIndian rivers.

Out of 3000 Alstom employees in the coun-try – mostly engineers – 900 are based inVadodara, which can annually produce equip-

ment to generate 1600MW ofpower. It has India’s largest (112

tonnes/250 MW) turbinerunner and it can produce1700 electric bars permonth.

The company is goingto install the 240 MWLower Jurala hydroelec-tric plant in the centralIndian state of Andhra

Pradesh, with the equip-ment being designed and

produced at its Vadodaraunit – the turbine designs are

currently being tested.

Alstom is working hard to tap into India’s major hydropower market, writes Raghavendra Verma

Expanding research in India

IWP& DCHooped Pelton runner


SEISMIC ANALYSIS

TALAS-FERGANA is a 700km long fault line in Kyrgyzstan,Central Asia. Although familiar to geologists little is knownabout this particular fault, except that it exhibits geologi-cal characteristics similar to the San-Andreas fault line in

the US. Indications from Kyrgyzstan are that it has the potential foran earthquake of similar intensity to those that occurred on San-Andreas in 1857 and 1906.

‘We now know that the Talas-Fergana fault has a long history ofactivity with the last faulting event occurring recently in geologicalterms, approximately 400-500 years ago,’ says Derek Rust a geolo-gist at the University of Portsmouth in the UK. ‘The longer the periodof time since the last ground rupturing earthquake, the greater thenext earthquake is likely to be. Another event is inevitable. It’s justa case of when.’

One factor will make the potential consequences of the next earth-quake even more catastrophic. The Talas-Fergana fault line cutsacross Toktogul, the largest hydroelectric and irrigation scheme inCentral Asia.

UNDER STRAIN

The Toktogul project is a 1200MW scheme with a 230m high damimpounding a 20km3 reservoir. It provides power and irrigationwater to Kyrgyzstan, Uzbekistan, Tajikistan, Kazakhstan and Russia.The countries’ competing demands for power and water mean thatToktogul is already the focus of cross-border tensions. The schemeis considered to be vital for the region’s economic, social and agri-cultural stability. Disruption could be catastrophic, putting the coun-tries’ already fragile economies at risk, provoking civil unrest, andproviding opportunities for the region’s extremist groups to exploitthe resulting disorder.

‘These are Central Asian countries that used to be together in the

Soviet Union,’ Rust explains. ‘Now they are all independent andrelationships can be strained. For example, over 75% of Kyrgyzstanis mountainous terrain over 2000m high. It is very cold and thereare high power demands for heating in the winter. So at the end ofthe summer, high water levels are required for the reserve of power.In contrast,’ Rust adds, ‘downstream Uzbekistan’s prime interest isirrigation. So it needs high water levels for use in the summer. Thereare major competing interests here and if this scheme was to failthrough seismic activity it could be catastrophic.’

Compounding this situation are 23 uranium mining waste dumpsin the region. Kyrgyzstan was the chief uranium mining area for theSoviet Union; while earlier gold mining left a legacy of mercury richmine tailings. Both these are vulnerable to seismically triggered land-slides and the sudden release of water. Furthermore, over 10Mpeople live in the most threatened area downstream from Toktogulin the Fergana Valley.

‘The violent ground shaking associated with a great earthquakeon the Talas-Fergana would be expected to generate significant land-sliding in this mountainous region. This is what happened with theSichuan earthquake in China in 2008,’ Rust explains. ‘Landslidemasses entering the reservoir have the potential for generating dam-aging tsunami effects. Outside the reservoir it is likely that landslide-dammed lakes would be created, as in Sichuan. These have thepotential for sudden release of impounded waters causing floodingdownstream, and possible mobilisation of the uranium mine wastedumps. Existing landslide-dammed lakes, probably associated withpast great earthquakes, also have the potential to be breached in theevent of a new earthquake.

‘Understanding the real threats to the environmental security ofthis region, and finding ways to mitigate against these, is crucial toavoiding conflicts over water and power supplies, and avoidingextensive pollution of vital lands,’ Rust adds.

Fighting the fear of failure

A NATO Science for Peace project will assess the geo-environmental security of Toktogulhydroelectric station, the largest hydro plant in Central Asia. Suzanne Pritchard spokewith NATO project director Derek Rust to find out more


SCIENCE FOR PEACEToktogul hydro project is now the focus of NATO’s Science forPeace project. Rust is the country project director and over a three-year period his team will research the geo-environmental security ofToktogul. They will examine existing seismic data and gather newinformation from satellite sensing imagery, aerial photography,radiocarbon dating of geological features and use portable seis-mometers.

‘Ours will be the first seismic hazard assessment of the Toktogulregion,’ says Rust. He explains that due to the hydro scheme’s posi-tioning on border territory between the former Soviet Union andChina, the area was previously out of bounds to western scientists.Little research was done by the Russians as, when Toktogul was builtin the 1960s, the country’s mainstream geology establishment hadactively dismissed the appreciation of plate tectonics. Consequentlythe significance of the Talas-Fergana fault line went unrecognised.

‘We are not directly studying the engineering integrity of the damitself,’ says Rust, ‘but rather the implications of seismic activity onthe reservoir and surrounding region. A breach of the dam wouldbe a catastrophic event. So we will recommend mitigation measuresto reduce these hazards and emphasise avoiding potential hazardsin the future by wise planning. Although it is too early to say yet ifwe will suggest more active measures to reduce risk.’

To minimise seismic effects the research team will anticipate whichreservoir slopes may fail and will be able to map these. They can alsoanticipate run-off from disturbing water in the reservoir throughtsunami effects, while a better understanding of which uraniumdumps are most vulnerable to ground shaking will be invaluable.Further active measures could include avoiding reservoir areas proneto run-up, dewatering slopes and providing good drainage to reducethe likelihood of failure.

INVALUABLE RESEARCH

Researchers from the University of Milan-Bicocca in Italy, and theNational Seismological Institutes of Kyrgyzstan and Uzbekistan,started work on the Science for Peace project in October 2008. Uponcompletion, the main findings of the study will be presented to thegovernments of the affected countries in 2011. Project director Derek

Rust has nothing but praise for the NATO initiative and the way ithas embraced his work.

‘We think that this kind of project at Toktogul is invaluable, butit does not immediately fit with some of the established fundingagencies,’ he concludes. ‘The fact that NATO promoted the politi-cal and scientific benefits of this project is fantastic.’

For more information contact the NATO country projectdirector, Derek Rust, School of Earth and Environmental

Sciences, University of Portsmouth, UK. Email:[email protected]

SEISMIC ANALYSIS

NATO funds Science for PeaceThe NATO Science for Peace programme dates back to 1956 when theimportance of political, economic and scientific factors was highlighted inrelation to international security. The programme continues with its aims ofenhancing security, stability and solidarity through increased collaborationand networking amongst countries.

Derek Rust and his team succeeded in securing €250,000 of NATO fundingfor their project. Any person can apply for a NATO grant who is expert in theirfield for which they are applying. Applications can also be made by individualscientists.

Topics funded by NATO include:• Food security.• Environmental security with implications for economic, cultural and political

instability.• Water resources management.• Disaster forecast and prevention.• Preventing conflicts in relation to scarcity of resources.• Non-traditional threats to security.

The deadlines for grant applications in 2009 are 1 March, 1 June and 1 November.

For more information on the Science for Peace programme log ontowww.nato.int/science/index.html or email [email protected]

Modelling Sichuan‘There is generally increasing awareness ofgeological hazards, such as those associatedwith earthquakes,’ says Derek Rust from theUniversity of Portsmouth in the UK, mentioningrecent events such as the Indian Oceantsunami on 26 December 2004.

The Sichuan earthquake occurred in China inMay 2008 and it is of great interest to Rust’sresearch team. The earthquake measured 7.8on the Richter scale and, most importantly,created around 30 landslide dammed lakes.

‘The Sichuan earthquake occurred in ageologically similar setting,’ Rust said. ‘Itprovides a model for the potentialconsequences of a similar earthquake on theTalas-Fergana fault.’

A major earthquake on a mountainous region isvery likely to produce large landslides. Rust’steam can only help to minimise the effects ofthis. ‘We can estimate long term slip rates onbig faults and their patterns of behaviour,’ hesaid. ‘But exact earthquake prediction is theelusive holy grail of earthquake geology.’

Photograph shows Yinxiu Town, wenchuanCounty, epicentre of the Sichuan earthquake

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SEISMIC ANALYSIS

system of discontinuities hereinafter called joints. In the latter event,the deformations of discontinuities may occur in two directions –either perpendicular to the plane of discontinuity including aperture,or possible slip along discontinuity. It may even be both. The firstdeformation is a non-linear function of change of stress perpendic-ular to the plane joints. In the event of fracture aperture, local break-ing of a quasi half space of lithosphere occurs. Discontinuity apertureoccurs when, as a result of a change of stress, the stress oriented per-pendicular to the discontinuity tends to become tensile.

Stress field in the earth’s upper crust is produced as a result ofgravitation, tectonic activities (including diapirism), and tempera-ture changes. Stress field is represented by principal stresses and tra-jectories of principle maximum stress. Principle stresses inlithosphere, as a rule, increase with depth.

Stress field in tectonically active areas of the earth’s crust observedover time is exposed to changes i.e. it is variable and beyond ourcontrol. Location, scope and speed of these changes for a givenlithosphere zone and its geo-mechanical characteristics depend ontectonic processes as well as changes of exogenous factors to whichit may be exposed (soil erosion, thawing of rock glacier formations,change of hydrostatic pressure, activation of landslides, impound-ing of man made reservoirs etc).

Variation of stress fields in the earth’s crust is accompanied by cor-responding deformations and displacements (including its upperzone) as well as potential changes (local) of its deformation charac-teristics. The latter changes may occur on a local or regional level,with even or uneven distribution (or both) along discontinuities.Displacements in the earth’s crust may also occur without a signifi-cant change of stress field (creeping, slipping etc).

Changes in stress fields occur irregularly with variable intensity,and with or without discernible dynamic effects (earthquakes). Inzones crossing trajectories of tectonic driving forces, variation ofstress fields and associated deformations may be rather divergentand unpredictable.

Variations in stress field and deformations taking place in theupper zone of the earth’s crust may be modified by dam site mor-phology. Variation may include residual stress relief with associat-ed deformations and dynamic effects. These changes may occur asa result of endogenous and/or exogenous processes.

In the event that a change of external (exogenous) load in the earthcrust coincides with tectonic activities, additional effects associatedwith their interaction may occur. Impounding and emptying of man-made reservoirs, as well as large fluctuations of ground water tables,may produce differential movement along discontinuities. The latteroccurrence is related to a decrease of contact stress.

Stress field changes and earth crust deformations occur with orwithout differential movements along the existing and newly devel-oped discontinuities. These may be accompanied by dynamic effects.In zones with instable stress field conditions the change of external(exogenous) load may induce additional tectonic effects with accom-

Analysing dam behaviourBosko J. Guzina analyses behavioural responses of damsbuilt in tectonically active or potentially active areas

VARIATION of stress fields and deformations in the zoneof the earth’s crust, which may or may not be accompa-nied by apparent dynamic effects (earthquakes), are cre-ated mostly due to tectonic activities. This phenomenon

may affect the dam via its foundation through interaction.As the end of a dam’s operational life approaches, the occurrence

of stress field variations and deformations in the earth crust – as wellas its cumulative effect on dam behaviour – becomes more probable.

Observation is often necessary to monitor the behaviour of damsand detect possible discrepancies, right from the design stage andthroughout the dam’s life. Early notification of changes, identifica-tion of their origin, prognosis for further development, and the effecton dam safety is of particular importance.

Determining the actual causes of induced changes in dam behav-iour – particularly if observed in the early stage – may prove to be arather complex multidisciplinary task.

The changes which could occur in the dam may be related to:

• Changes of physical and mechanical properties of dams, theirbedrock or both.

• Endogenous processes that took place in the lithosphere and thenthrough bedrock were transferred to dam itself (tectonic activities).

Changes or anomalies in dam behaviour could be similar in bothcases mentioned above – and both issues are addressed in this paper.

As anomalies in dam foundation behaviour related to endogenousactivities often develop and occur intermittently, they are usuallyidentified only after a period of dam use – when damage has alreadyoccurred on a dam or its appurtenant structures.

This paper is intended to help facilitate early discovery and iden-tification of the second phenomenon listed above, and its effects ondam foundation behaviour. In addition, it is intended to encouragethe upgrading and modernisation of monitoring systems, and meth-ods of interpreting the data.

VARIATION OF STRESS FIELDS AND DEFORMATIONSIN THE EARTH’S CRUST

The present analysis considers the earth’s crust as a heterogeneous(quasi) half -space divided into matrix blocks by grid discontinuities.Discontinuities are mainly represented by ruptures resulting fromtectonic actions and other loadings, or their variations. Each of thetwo elements of half-space (matrix and discontinuities) are charac-terized by their specific geo-mechanical properties affecting defor-mation and stress field of the earth’s crust i.e. their response to theaction of exogenous and endogenous processes.

In the earth’s crust, surface stress fields may prove rather unevenand are governed by morphology, temperature changes etc. Variationof deformations in the crust or rocks as a result of the variation ofloading are related to the deformation of block matrices and of a

Mosul dam, Iraq


panying deformation and dynamic effects.With the exception of large-scale earthquakes, the variation of

deformations in the earth’s crust often remains unnoticed. They areobserved primarily in lengthy constructions such as roads and tun-nels where they are often attributed to soil instability, temperaturechanges and other influences. Standard geodetic methods, besideslevelling, are often not helpful in identifying deformations in theearth’s crust of endogenous origin.

Vertical movements in the superficial zone of the earth’s crust maybe related to a change of external loading with or without an induc-tion of tectonic influence on the variation of tectonic loading.

ALTERATIONS IN PIEZOMETRIC HEAD

Alterations of piezometric head field within the aquifer associatedwith variations of stress field and deformations in the earth’s crustare the subject of the present study. Here the aquifer denotes a partof the earth’s crust with hydraulically potentially active porosityfilled with water i.e., a permeable rock zone saturated with waterand with a degree of permeability that allows water to be withdrawnor injected.

Transient changes of piezometric head fields may occur as theresult of active tectonic processes, fluctuations of barometric pres-sure, gravitational forces as well as the influence of other loadingson lithosphere.

For a given change of loading, alterations of piezometric headfields are governed by a type of aquifer as well as the type and char-acteristics of its hydraulically active porosity.

In this respect we may distinguish the following aquifer types:

• Unconfined or semi confined aquifer whose upper surface is indirect contact with atmospheric pressure.

• Completely confined aquifer with no direct contact with atmos-pheric pressure.

When a change of tectonic loading occurs, the groundwater in theaquifer takes over a part of the loading. Water retained in joints takesover a part of joints system loading while water held in spongy poros-ity replaces a part of the rock matrix loading. In unconfined aquifers,the partial take-over of varied tectonic stresses is temporary.

In unconfined (open) aquifers, the change of tectonic load in theaquifer zone results in a temporary change of the piezometric headgradients and migration of water towards free surface, or vice versa,and through hydraulically active porosity. The latter migration ofwater lasts until the initial changed state of piezometric head fieldswithin the hydraulically active porosity has been established. Duringthe latter process the stress field in the rock matrix and contact stressin the joints system is finally established – all this assuming therewere no changes of hydrological conditions (inflow or outflow ofwater) in the aquifer.

Amplitude and duration of temporary changes in the piezometrichead field depends on:

• Magnitude and temporal course of the change of tectonic load(velocity).

• Geometry, hydraulic characteristics and aquifer boundary conditions,• Deformation characteristics of joint system porosity.

Somewhat accelerated short-term changes of piezometric head fieldmay be expected in the event of earthquake.

Additional (partially) reversible deformations in lithosphere occuras a result of a piezometric head field transient alteration. Pertinentdisplacements last until a stationary state of piezometric head fieldis established and final deformation of the lithosphere related to achange of tectonic load of fractured half-space has taken place.

In confined aquifers the change of tectonic loads simultaneouslyentails a permanent alteration of piezometric head fields, except inthe event of a hydraulic break through overlaying impervious layer.The latter may occur in the event of an increase of tectonic loadwhen the aquifer hydrostatic pressure to the overlaying strata

exceeds geostatic pressure.Closed point piezometers with automatic continuous pressure

recording are the preferred choice to monitor the potential impactof stress field variations. In certain cases multi-level monitoring (atvarious borehole depths) is a suitable method for recording piezo-metric head.

Piezometers should be placed on both sides of the structure tomonitor potentially active faults. In limestone aquifers, piezometersshould also be placed below the zone of intensive karstification. Forconfined or semi confined aquifers, open air piezometers or piezome-ters with as narrow a stand pipe as possible (placed above the aquifercovering layer) could be used to reduce the piezometers inertia.

Use of piezometers as mentioned above should make it possibleto identify, and predict, the presence of stress fields variations in thelithosphere in zones with hydraulically effective porosity filled withwater. This would also involve continuous automatic recording ofpiezometric head and with exclusion of hydrologic influences.

Earthquakes are preceded by an alteration of stress fields in thecorresponding part of the lithosphere. Depending on the velocity ofthese changes in the aquifers, they are accompanied by correspond-ing changes of piezometric head fields. The latter implies an earth-quake itself as well as a period which follows the earthquake whenthe changes which occur are of highest intensity. This means thatvariation of piezometric fields may either be considered as a predic-tion and/or a consequence of an earthquake.

When there is an alteration of piezometric heads associated withthe change of tectonic load, the contact stresses induced along somediscontinuities may, over time, temporarily reduce or follow thesechanges. The latter may further induce differential displacementsalong the discontinuities with or without apparent dynamic effects.

VARIATION OF INTERACTION BETWEEN THEDAM AND THE FOUNDATION BEDROCK

The dam foundation bedrock represents the upper surface of thelithosphere and, together with the dam, participates in stress fieldvariations and deformations occurring in the earth crust as a resultof tectonic activities .

The term dam in this paper implies all appurtenant facilitiesincluding screens, grout curtains, drainage systems, water intakes,discharge or spillway bodies, adjacent hydro power plants etc. Thevariation of interaction of endogenous origin implies the variationof state of stress and deformations along the dam foundation jointinduced by the stress field variations in the zone around the dam.

Following the change of interaction, the dam may not show anynoticeable signs of damage for a considerable time.

For a certain change of stress field and deformations in the lithos-phere, the change of interaction and subsequent effects on the damdepend on, but are not limited to:

• Morphology of the river valley.• Characteristics of stress field in the upper part of the lithosphere

in the dam zone.• Geological and geo-mechanical characteristics of the dam foun-

dation.• Dam structure and layout.• Original in situ state of stress field in the dam bedrocks.• Combination of the above factors.

Lithosphere deformations of endogenous origin may develop in thedam zone with or without differential displacements along discon-tinuities in rock, including their aperture which may or may not beaccompanied with creation of new fractures.

Differential displacements along discontinuities may beunfavourable for concrete dams founded on hard rock. In the caseof concrete gravity dams constructed in extremely deformablebedrocks, the influence of the interaction could possibly end at foun-dation bedrock plastic deformations entailing a change in stressesin the dam to certain extent, but without any mechanical damage tothe structure.

SEISMIC ANALYSIS


The variation of interaction may affect the integrity and safety ofconcrete dams founded partially or fully in hard fractured rock. Inthis case the dam could represent an obstacle for undisturbed defor-mation of lithosphere surface and could be exposed to significantloads by means of interaction which it would not be able to bearwithout deformations and structural damage. The latter is particu-larly the case for dams constructed in canyons.

The change of interaction may also affect grouting galleries ofearthfill dams and grout curtains or screens. This would happen ifthe change of stress field in the lithosphere results in a widening ofthe river valley at the dam site followed by the aperture of disconti-nuities. The latter case could prove rather risky for dams of any typefounded in erodible rocks and more so in case of the presence of sol-uble rocks in dam bedrocks.

Due to a change of interaction of endogenous origin, deforma-tions and displacement along the foundation joint are possible in alldirections regardless of deformations associated with hydrostaticpressure against the dam.

A very complex state of displacements and deformations maydevelop in dams founded in geo-mechanically heterogeneousbedrocks.

In the case of arch dams constructed in steep canyons, differentialdisplacements between the blocks of rocks at the flanks of a dammay not affect the structure for some time.

The effect of stress field variation and deformations in lithosphereof endogenous origin to the change of interaction is usually identi-fied only after a longer period of observation at dams. During astructures lifetime, the changes of interaction may re-occur severaltimes, and not always in the same direction. However any damageor degradation is cumulative.

Early identification of the presence of interaction changes in a damfoundation is not an easy task. More so as such effects often resem-ble those associated with exogenous influences, including weathering.

ANOMALIES IN FOUNDATION BEDROCK BEHAVIOUR

Anomalies in dam foundation behaviour may indicate changes ofstress field and deformations in the lithosphere of endogenous origin.

In this paper the dam foundation behaviour implies variations ofstresses, deformations and displacements, as well as piezometrichead field in dam bedrocks and water elevation in the reservoir.

The anomaly of dam foundation behaviour denotes unexpectedchanges related to:

• Permanent displacements and deformations of dam foundationexceeding the anticipated values.

• Permanent change of the function: displacement and dam foun-dation deformation versus water elevation in the reservoir i.e. itsexternal loading.

• Unexpected temporary or permanent changes of piezometric headfield in the dam bedrock as well as the amount and pattern of per-colating water.

When determining the presence of anomalies it is first necessary todetermine and eliminate possible errors in measurements and read-ings as well as data obtained by means of defective or poorly cali-brated monitoring equipment.

As a majority of the listed anomalies may be a result of endoge-nous and exogenous factors, the present paper gives a summary ofthe anomalies for each factor individually. The aim of the summa-ry is to determine the presence of stress field variation and defor-mations in a dam of tectonic origin and to recognize their possibleinfluence on the structure and its foundation.

ANOMALIES OF EXOGENOUS ORIGIN

Water acts on dam bedrocks through hydrostatic pressure. The dis-tribution of load which the dam transfers to the bedrock dependson the type of dam, its structure and layout, geo-mechanical char-acteristics of the bedrock itself and the initial in situ state of stress

in dam bedrocks. Direct hydraulic load on the foundation dependson the established piezometric head field which may be significant-ly affected by sealing and drainage works in dam foundationbedrocks and their hydraulic effects.

Permanent dam foundation deformationsPermanent deformations on the foundation may also be related tothe rock matrix. Over time, permanent deformations of fracturedrock under the influence of cyclic loading increase with a progres-sive decrease of yield (except for the case of dam failure).

In the system of joints when a dam external loading is known, per-manent deformation depends on joint morphology, presence of jointfilling and its geo-technical characteristics. An increase of perma-nent deformations may also occur in the event of joint filling mate-rial being washed out, resulting in permanent squeezing of fractures.

Permanent alteration of piezometric head fieldsChanges in piezometric head fields may be associated with:

• Clogging of joint system.• Degrading grout curtain and joint system in dam bedrocks.• Dissolution or erosion of foundation rock matrix.• Clogging of drainage system (in bedrocks of a dam).

Permanent changes of piezometric fields and seepage of waterthrough the dam bedrocks as a rule occur gradually and may com-mence at any time during operation of the dam.

Degrading of grout curtains is associated with grout wash outfrom the joint system or its original filling in the grout curtain zone.In certain cases the resistance of grout mass to wash out may eveninitially be low or it may get lower over time due to associated phys-ical and chemical processes.

ANOMALIES AS A RESULT OF ENDOGENOUS FACTORS

In this case, possible anomalies depend on stress field variations anddeformations in the lithosphere in a wider dam zone, as well as onassociated variation of interaction between the dam structure andits bedrock. The general characteristics of anomalies in this case arethat they occur generally regardless of the external loading of thedam. Those anomalies occur mainly sporadically and may be initi-ated during construction of the dam. They are usually identified onlyin an advanced stage.

Permanent displacement and deformations of dam bedrocksOne of the essential characteristics of those movements and defor-mations is that changes may occur in all directions regardless of theorientation of the direction of active loading against dam bedrocks.The movements and deformations occur cumulatively and maychange both orientation and direction during the lifetime of the dam.Although the dam bedrock deformations generally follow trajecto-ries of the maximum principle stress variation in the lithosphere, therelevant change of interaction in the foundation may prove very het-erogeneous.

Deformation changes in earth fill dam bedrocks may be identifiedthrough the use of strain gauges placed in the clay core close to foun-dation as well as through deformations and movements in a grout-ing gallery, should it exist.

Those deformations may occur as differential displacements ofmatrix blocks along discontinuities and as apertures of discontinu-ities governed by the previous state of stress field in dam foundationbedrocks (the latter may be first anticipated in the dam abutment).

Change of deformation characteristics in the foundationDeformations of fractured (quasi) half-space consist of deformationsof rock matrix and those of the fracture system. The relationbetween strain and stress with joint system is a non-linear function.Subsequently, if a change of stress field and deformations in the dambedrock due to tectonic action occurs, it would then result in achange in the dam foundation deformation characteristics.

SEISMIC ANALYSIS


Changes in the dam static foundation modelAs a joint system in dam bedrocks cannot withstand tensile stresseswhen there is hydraulic loading, the dam bedrocks may behave as:

• a) Half-space• b) Quarter-space• c) Combination of a) and b) but governed by prevailing in situ state

of normal stresses in joints and water elevations in the reservoir.

In the event of case a above, hydraulic loading transferred from thedam, as well as that which directly acts against bedrocks, will beaccepted by the wider rock area below and around the dam. In theevent of case b, hydraulic loading will accept only the rock below thedam (or clay core at earthfill dams) and downstream from the dam.In the event of case c, with the change of water elevation in the reser-voir the static model of foundation may be changed from a via b to c.

In the event of a change of stress field in dam bedrocks resultingfrom endogenous (tectonic) processes, changes may occur in thestatic model of the dam.

Permanent changes of piezometric head field and water seepageChange of stress field in dam bedrocks will result in the change ofdeformations of the joint system and subsequently the change ofhydraulic characteristics of bedrock. The grouting curtain is alsosubject to deformations. As a consequence, a change of percolationthrough dam bedrocks and an alteration of piezometric head fieldentailing a change of hydraulic load of the system of joints in dambedrock would take place. Opening of joints crossing the curtainmay be accompanied by their wash out, furthering increasing per-colation through dam bedrocks (the same as in the case of exoge-nous loading). If a system for control and monitoring percolatingwater has been provided below the dam, it could prove a more reli-able indicator of changes in piezometric head field in dam founda-tions than individual piezometers.

Permanent damage of the grouting curtain and associated effectof the change of piezometric head field may also occur as a result ofpropagation of seismic waves.

Transient alterations of piezometric head fieldTransient alteration of piezometric head field in dam foundation isa reliable indicator of the change and a sign of variation i.e. changeof stress field in the lithosphere in a wider dam zone. Those changesmay strongly affect the stability of concrete dams and, in particular,arch dam abutments in the event of an improper or clogged drainagesystem. The same implies for landslides in and around reservoirs.

A differentiation should be made between transient and short-termchanges of stress field associated with seismic waves propagation.

Deformations in dam bedrocks resulting from earthquakesSeismic waves during earthquakes result in transient changes ofstress fields in the earth crust. In the zone around the earthquakeepicentre, transient as well as additional permanent deformations ofthe existing and possibly newly formed discontinuities with perma-nent additional change of stress field may be induced.

Possible additional permanent changes of interaction in the damfoundation bedrock may also take place. These changes depend onseveral factors such as river valley morphology, geo-mechanical char-acteristics of bedrock (matrix and joint system), in situ state of stressfield in the bedrock and the type and structure of the dam.

FUTURE CONSIDERATIONS

It is obvious that for dams built in tectonically active areas there isa high likelihood of the occurrence of such variations of stress fieldand deformations in the earth crust that may affect the structure,including its safety and operating life. Anomalies in dam foundationbehaviour are probable indicators of a change of stress field anddeformations in the lithosphere.

It is therefore essential to determine the presence of anomalies indam bedrocks, to predict their further development and analyze pos-

sible effects on dam integrity. Any rehabilitation measures shouldof course take into account that identified anomalies could be asso-ciated with endogenous (tectonic) or exogenous factors.

Identifying cause and origin of individual identified anomalies mayprove a rather complex task as they are similar in both processes.For identifying early changes of stress field and deformation ofendogenous origin in dam bedrocks it is important that a propermonitoring system with a high degree of accuracy and reliability isestablished. The system and pertaining analysis of measurementresults is necessary to continuously innovate and upgrade during adam’s lifetime.

Particular attention should be given to establishing a corre-sponding system for continuous automatic observation of piezo-metric head field in dam bedrocks, as the unexpected transientchanges in piezometric head field may be regarded as a reliable indi-cator of a change of stress field in bedrocks of endogenous origin.

When identifying anomalies in dam bedrock behaviour, it is nec-essary to eliminate the possibility of defective monitoring equipmentand ensure accuracy of measurement.

Analysis of anomalies identified in dam foundation behaviour ofendogenous origin should include a prognosis of their further devel-opment and possible influence on integrity and safety of the dam.This could prove a very difficult task considering a wide spectrumof possible solutions.

Assistance in solving the above problems should be subject of fur-ther tectonophysics research, with investigations and studies updat-ed throughout a dam’s life.

Bosko J. Guzina, Civil Engineer, 91, Jove Ilica street,11000 Belgrade, 38000 Serbia. Tel: +381 11 2493179,

Email: [email protected]

SEISMIC ANALYSIS

References1) Guzina B., Tucovic I. (1970) Some properties of elastic macro-discontinuum in rock, Proceedings of the Second Congress of internationalSociety for rock Mechanics, Belgrade.

2) Pougatsch H. (1982) Unexpected behaviour of a large arch dam inSwitzerland, XIV Congress on large dams , Rio de Janeiro.

3) Alonso F.M., Gomez L.G., Romero H.J.L (1982) The hydraulicauscultation as a monitoring test of dam safety, XIV Congress on largedams, Rio de Janeiro, May 1982.

4) Mulargia F., Brocio V., Achilli V., Baldi P (1985) Evaluating a seismicquiescence pattern in southeastern Sicily , Tectonophysics, Volume A16-No341 - July 10.

5) Ziqiang L., Xiling C., Jiageng C., Zhang Zi L.J. (1985) Someconsiderations on recent tectonic stress field of China, Tectonophysics,Volume 117 No ½ - August 1

6) Sir Alexander Gibs and Partners (1985) Independent Report on thefailure of earthwork instruments Mosul dam, London, March 1985

7) Guzina B., Obradovic J. (1988) Neotectonic impact on dam* foundationsealing, XIV Congress on Large Dams, San Francisco.

8) Guzina B., Saric M., Petrovic N. (1991) Seepage and discolouration atfoundations of a dam* during the first impounding of the reservoir, XlVCongress on Large Dams , Vienna.

9) Letica, V. (1998) Analysis of damages and repairs of the left side ofBajina Basta Dam, R 28, XIX Congress on Large Dams, Florence.

10) Guzina B. (2000) Hydraulic loading of fissured porous rock, XXCongress on large dams, Beijing

11) Energoprojekt. Results of piezometric observation for HE Piva-MratinjeDam for 2003

12) Bozovic A., Misic D. (2008) Monitoring of the state of stresses in thebody of Bajina Bašta Dam , I Serbian Congress for Large Dams,

* Mosul Dam, Iraq

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PROJECT DEVELOPMENT

TUNNEL EXCAVATION

Six Sandvik DT series tunnelling jumbos will be used to excavatethe project tunnels. The jumbos will work together with threeSandvik DC300 drilling rigs that are already on site.

The Sandvik drilling rigs and jumbos have been purchased by theJV from Sandvik Chile in Santiago, and will be serviced on the siteby a team of Sandvik personnel who will be based there for the dura-tion of the project. The three Sandvik DC300 hydraulic, self-pro-pelled drilling units have so far been used for stabilising the rock facefor the powerhouse excavation, where they have been drilling holesfor the benching.

The DC300 machines, specifically designed for operations such asbenching, are drilling 3.5m deep holes using Sandvik R32 bench drillingbits, sized at 38mm diameter and 64mm diameter, representing thelower and upper range of drilling that the DC300 can undertake.

Blasting is being carried out daily, and the stabilisation will becomplete by the time the Sandvik jumbos begin tunnelling.

The six jumbos are all Sandvik DT 720C units, and will be work-ing on the two main tunnels, the surge chamber, and other tunnellingwork on the project. Built on diesel-driven carriers, they are electro-hydraulically powered and equipped with two booms designed forextremely fast rock drilling across a maximum cross-section of 70m2,and will be working at a maximum height of 7m and width of 11m.

The jumbos will mainly be equipped with Sandvik R32 drillingtools of 45mm diameter, fitted with nine-button RT300 bits that willbe sharpened in the site workshop by Sandvik personnel; extendingthe life cycle of each bit

In each of the two main tunnels, the DC300 rigs will follow thejumbos to carry out the reinforcement drilling, using a Sandvik R32drilling tool of 51mm diameter for the central hole on each sectionand an R32 of 38mm for the surrounding holes. Once the rein-forcement is done, the tunnel will be lined with shotcrete.

Otto Krahan says that despite the uncertainties relating to the typeof rock that will be encountered, the projected rate of tunnel advancewill be 9m per day, to be achieved in two cycles of drilling, blasting,cleaning and reinforcing per 24-hour period. The construction periodfor La Confluencia is expected to be three years, depending largelyupon the rock conditions encountered by the tunnellers.

www.sandvik.com

LOCATED in the Tinguiririca Valley in the foothills of theChilean Andes, the 158MW La Confluencia is a run-of-riverproject involving the design and construction of a power-house to install two turbines, approximately 19km of tunnel

and two river diversions. The project – which is expected to costUS$350M – is being developed by Tinguiririca Energia, an electric-ity operating company made up of the Australian utility PacificHydro and SN Power, a Norwegian venture of utility Statkraft andthe Norfund Power Invest AS fund. Main contractor on the projectis Hochtief-Tecsa Joint Venture.

La Confluencia is upstream of the La Higuera project, which isalso being developed by the Tinguiririca Energia. Although beingdeveloped entirely separately of each other, the two projects aredesigned to operate in cascade, and both can operate independent-ly in the event of closure of either plant. It is expected that both pro-jects will generate approximately 1400GWh annually.

La Confluencia is located on the Tinguiririca, Portillo and Azufrerivers and consists of intakes and conveyance systems on twobranches diverting flows to a surface powerhouse.

The Portillo branch comprises a low weir and spillway on thePortillo River at 1465m asl. Water will pass through a desander andshort open channel before entering an 11km low-pressure tunnelthat runs to the surge chamber above the powerhouse at the con-fluence of the Azufre and Tinguiririca rivers.

The Tinguiririca branch consists of a low diversion weir and spill-way across the Tinguiririca River at 1450m asl that will divert par-tial flows through a desander and short open channel to a regulationpondage of 1.2Mm3 live storage capacity.

Water from this will be taken via a 9.3km low-pressure tunnel thatjoins the surge chamber above the powerhouse.

Both the Tinguiririca and Portillo branch tunnels will terminateat a concrete lined vertical shaft dropping to the open-air power-house via a concrete and steel lined high-pressure tunnel. Hochtief-Tecsa JV plant manager Otto Krahan says that tunnelling forms thedominant part of the works.

As the Andes are characterised by uplifted sedimentary, vol-canogenic and intrusive units of highly variable nature, it has notbeen possible to predict with certainty the rock conditions that thecontractor will find once tunnelling begins. Nonetheless, fastprogress is necessary and as there will be up to 10 active fronts inthe two tunnels during the greater part of the construction period,the tunnels will require intensive management.

Six Sandvik DT series tunnelling jumboswill be used by main contractor theHochtief-Tecsa Joint Venture forexcavating the tunnels on La Confluencia,a run-of-river hydroelectric project beingbuilt in the Chilean Andes

Playing ajumbo role

IWP& DC


PROJECT DEVELOPMENT

RCC 08 also took the initiative in taking more of a teaching than apresentation approach. As Shane Dunstan from ARAN Internationalexplained: ‘We did not invite speakers to submit papers on a topicof their choice. The aim of the seminar was to educate practitionersand young engineers in the basic principles for designing and con-structing RCC dams. When developing the programme we gathereda group of international seasoned experts and together we devel-oped a list of topics to be discussed. All presenters were encouragedto present information free from bias and to draw on the broadestrange of design and construction practices possible.’

RCC 08 wanted to bring the dam building fraternity together foreducational purposes. On the one hand delegates and speakers are

MORE than 170 international delegates gathered inAustralia for a structured training seminar to discussspecialist RCC dam techniques and new technology.The purpose of RCC 08 was to help achieve better

quality and more cost-effective dams through greater awareness andunderstanding. Topics under discussion included:

• Tracing the history and evolution of RCC.• Avoiding costly and risky mistakes.• Finding better designs and methods.• Using the most appropriate equipment.• Knowing who to ask for help.

A specialist training seminar was held recently in Australia to educate practitioners andyoung engineers on the design and construction of RCC dams

The lowdownon RCC

competitors, but at seminars like this they are keen to share theirpassion and experience of RCC dams with one other.

OPINIONS VERSUS PRINCIPLES

John Green knows all about competitiveness and is a specialist esti-mator who has been involved in estimates for 17 RCC dams world-wide. ‘We’re not in rocket science in RCC,’ he said. ‘The good thingis that RCC is still in its infancy. We have to be inventive. The realfun part of the game is the competitive tendering. It spurs you on tolook for innovative solutions. For example I believe that the Chinesehave used cableways to place RCC and I have also worked on onedam where we were very close to using recycled concrete.

‘With RCC you have to avoid the tyranny of status quo. If you’renot careful you’ll find yourself with people who say it’s done likethis on that job and so you should do the same on this too. You havethe tremendous opportunity to be inventive,’ he told delegates.


‘When approaching an RCC project you must have an open mind.Don’t have pre-conceived notions.’

Dave Murray, senior project manager for dams at QueenslandWater says that dam owners don’t have time for pre-conceived ideas.‘We don’t care about strongly held opinions,’ he said. ‘We just lookat the best value for money. Strongly held opinions don’t take usanywhere as an owner.’

‘You need to listen carefully and divide strongly held opinions fromsoundly based principles,’ Trevor Dunston from ARAN Internationalwent on to tell delegates. ‘It’s up to you to split the difference.’

TENDER INFORMATION

Worldwide, RCC is becoming the method of choice in dam projectsand it is a successful cost-effective solution. But, as John Greenemphasises, you must not settle for ‘comfortable tendering’ on anRCC project.

‘Every job is different and you’ve got to treat it differently. Butyou’ve also got to set out to learn more about that project in a com-petitive tender than anyone else knows,’ Green said. ‘The generalphilosophy to apply is to treat a big job as a small job and vice versa.Give a small job the respect it deserves and don’t be overwhelmedby a big job. You’ve got to be competitive. Making every effort totake a dollar out is very important.’

Pozzalan provides a good opportunity to be innovative when pric-ing for an RCC project, but Green warns that you have to have thetime to develop it if using local resources. For example, in Asia ricehusk ash can be a good pozzalan, while volcanic ash, crushed brickand fly ash can also be used.

Engineering terminology can also play a part in the cost-effec-tiveness of a good RCC projects. ‘In general, when people talk aboutRCC in engineering terminology they talk about compacted m3. Tome there is no such thing as m3 in earthworks,’ Green says. Hebelieves that the precise nature of m3 should be clarified. Australiancompany ARAN has set the pace in their literature by talking aboutcompacted m3. ‘The difference between compacted and loose m3 inRCC can be as much as 20%,’ Green said. ‘I’ve even seen more thanthat and this can make a big difference.’

Having a model of a good check list when estimating the dura-tion of the job can also make a difference. ‘You need to establish allfactors and look at the job on its merits and use your judgementwhen estimating,’ Green said, listing factors to include:

• General operational efficiency.• Mechanical efficiency.• Learning curves.• Foundation delays – as these are often so undulating.• Gallery restrictions – can impact on productivity of the total system.• Finishing restrictions – at the top of the dam it becomes narrower and

so there is less room for equipment which affects work efficiency.• General placing delays.

PROJECT DEVELOPMENT

Above: Brain Forbes, manager of major dam projects at GHD, Australia

www.r izzoassoc.com

Phone 011.412.856.9700 Fax 011.412.856.9749

Since 1984

PROUDLY BUILDING ON YEARS OF RCC & DAM CONSTRUCTION EXPERIENCE.

25


Reverse factors or interruptions that can cause delays include:

• Placing waterproof membranes.• Layer joints.• Wet weather delays (can include flooding).• Hot weather delays.• Programming delays.

Another important point Green covered was the handover of a pro-ject from the project estimator to the construction people. ‘It isextremely important,’ he said. ‘The estimator should insist on aproper handover if you want your organisation to kick a good goal.’

RCC DOWN UNDER

Keynote speaker, Graeme Newton, helped to give an Australian per-spective on RCC dams. Newton is CEO of Queensland Water,Infrastructure Pty. This is a specialised vehicle established by theQueensland government to gain approval for and deliver majorwater infrastructure projects to help solve the state’s water supplycrisis. Queensland currently has high level water restrictions.Massive population growth over the past ten years combined witha drought has compounded the need for building new dams. Theseinclude the Traveston Crossing and Wyaralong dams, both of whichare likely to be built using RCC technology.

Traveston Crossing dam on the Mary river is a proposed A$1.6Bstructure. Currently still undergoing the relevant approval, con-struction is due to start early this year with completion scheduledfor 2011. With a 153,000Ml capacity, it will contribute to 27% ofthe additional water supply required by 2015 and supply enoughwater for 800,000 people in southeast Queensland per day.

The project has been packaged to benefit large, medium and smallfirms within the construction sector and encourage and fostergrowth in the industry. Market research has been commissioned togain a greater understanding of current market conditions and todeliver a high performance team to manage the project. In the longterm the University of the Sunshine Coast in Queensland will studythe long term benefit the project has for local industry and will assessthe best way to utilise local suppliers.

WEALTH OF EXPERIENCE

RCC 08 was held from 9-11 April 2008. Expertise was drawn fromeminent professionals involved in the field of RCC, including:• Brian Forbes – manager of major dam projects for international con-

sultants GHD, Australia. Forbes was the principal engineer/reviewerfor eight of the first nine RCC dams to be built in Australia. Sincethen he has worked on over 30 major RCC dams in 15 countries.

• Francisco Ortego – principal and director of FOSCE ConsultingEngineers in Germany. He has been involved in the planning, designand construction of more than 50 large RCC dams in 20 countries.

• Ken Hansen – senior vice president of Schnabel Engineering in theUS. He has consulted on more than 55 RCC dams in 11 countries.

• Trevor Dunstan – executive director of ARAN International inAustralia. His continuous mix, volumetric proportioning plantshave been used on more than 30 RCC projects with volumesup to 1Mm3.

To obtain DVD proceedings of RCC 08 or for moreinformation on any future events, please contact

[email protected]

PROJECT DEVELOPMENT

IWP& DC

Above and top left: International experts shared their experiences with delegates at RCC 08; Bottom, right: Francisco Ortego of FOSCE Consulting Engineers


REFURBISHMENT

• Conceptual design of the re-build including analyzing and devel-oping various options to re-build the project. Construction costsand schedule, as well as potential regulatory challenges witheach option, were be fully evaluated.

Following substantial investigation and design, Rizzoconcluded that substandard construction and instrumentationproblems were partly responsible for the breach, earmarkingthe following points as key causes: stability failure; poordesign; specification and maintenance of instrumentation andcontrol systems.

It was determined by Rizzo that a repair of the existing dike wasnot technically feasible due to flaws in the original construction.Substantial areas of the existing dike were founded on residual soil.Additionally, few construction controls were utilized to control thegradation and character of the rock fill.

Due to this and a number of other factors, a complete re-buildof the upper reservoir was required.

AT 5:00 AM on 14 December 2005, the northwest cornerof the Dike around the Taum Sauk Pumped StorageProject’s Upper Reservoir in Reynolds County – about 100miles (160km) south of St. Louis, Missouri – breached over

a width of about 213m (700ft), causing a catastrophic, uncontrolled,rapid release of water down the west slope of Proffit Mountain andinto the East Fork of the Black river (see Figures 1 and 2).

Paul C Rizzo Associates, Inc. was hired by the dam’s ownerAmerenUE to investigate the cause of the 408MW project’s dam col-lapse, as part of a Federal Energy Regulatory Commission (FERC)requirement. The company was retained to address the following:• Detailed forensic engineering to determine the causes of the fail-

ure. Analysis included stability and seepage, dam breach (todetermine time of failure and to evaluate mode of failure), com-plete review of instrument control systems, sediment transport,detailed mapping of breach zone, and drilling and sampling ofremaining portions of the dike.

ReservoirConcrete face andplynth block

Foundation rock

Parapet wall

Uncompacted rockfill(placed in 10 foot lifts

Residual soil &weathered rock

Figure 1: Aerial view of the breach

Rebuild work is currently being carried out on the Taum Sauk pumped storage project inMissouri, US, following a catastrophic failure of the scheme’s upper reservoir in December2005. Engineer of record and construction manager, Paul C Rizzo Associates, providesIWP&DC with details on the work involved in this important project

Rebuilding Taum Sauk

Left – Figure 2: An overall aerial view of the flow path is shownBelow – Figure 3: Old Upper Reservoir design

PROJECT HISTORY

The Upper Reservoir at the Taum Sauk pumped storage plant wasconstructed in the early 1960’s with an uncompacted rockfill dikewith a concrete face – it was basically an early concrete faced rock-fill dike. The project was completed in 1963 as a pumped-storageproject, with an upper and a lower reservoir. The lower reservoir,operated as a run-of-river reservoir with outflow being maintainedat approximately equal to natural inflow, provides storage for waterto be pumped to the upper reservoir at night or during periods oflow power demand.

The original construction of the Upper Reservoir was accom-plished by flattening the top of Proffit Mountain, using rhyolite andexcavated residual soil to construct the existing concrete face rock-fill dike. After the breach, it was discovered that significant quan-tities of residual fines were mixed with the rock, and the rock itselfhad a wide range of particle sizes, ranging from gravel sizes to aslarge as 4-5ft (1.2-1.5m) in diameter. The Forensic Report authoredby Rizzo is available on-line at the Federal Energy RegulatoryCommission’s website: www.ferc.gov.

WHY RCC?The new dam is founded on fractured rhyolite with deep weather-ing features, intrusive granites and weathered diorite dikes. A sym-metrical RCC section is being constructed to provide adequatefactors of safety to meet FERC stability criteria considering the sub-scribed foundation conditions of the rock.

The subsurface information obtained during the original con-struction of the dam and additional borings drilled during the designof the new RCC dam indicated the prevalence of weak seams alonglow angle discontinuities with the foundation rock. At many loca-tions, these weak seams consist of low plasticity clay. Therefore,Rizzo performed sliding stability analyses of the dam assuming thepresence of the clay seams at various depths within the foundationrock. It also calculated the yield acceleration along these potentialfailure surfaces. The lowest factor of safety is postulated to occurwhen the clay seam is parallel to the rock/dam interface at an angleof 10 degrees with the horizontal at a reasonable depth below thebase of the dam. For any other angle of the seams (either upwardor downward), the factor of safety is higher than the factor of safetyfor clay seams parallel to the rock/dam interface.

The required friction angle with no cohesion was calculated forvarious depths to the clay seams. The results of these analyses indi-cate that a symmetrical RCC dam with 0.6H:1V upstream anddownstream slopes constructed along a foundation sloping at 10degrees or less will meet all FERC stability criteria even if a clay seamwith a low friction angle is encountered within 20ft (6m) of the baseof the dam. A conventional RCC dam section would requireRCC/rock and rock shear strengths considerably higher than a clayseam. For this reason, the new RCC dam will consist of a symmet-rical section similar in many ways to a hard fill dam. All of thesefeatures have resulted in a time consuming and intense foundationpreparation effort as illustrated in Figures 4 and 5.

The initial design contemplated using a conventional gravity damsection with vertical upstream face and a steep downstream face,which contemplated a relatively high strength RCC and fairly cleanaggregate. As preliminary studies [1] revealed significant presenceof fines in the existing rockfill dike, it was realized that washingaggregates would demand a costly, difficult operation due to thewater treatment equipment required to keep the operation self-con-tained and in compliance with environmental regulations applica-ble to the project. It was concluded that a dam section designed toprovide an adequate factor of safety to meet FERC stability criteriaconsidering the subsurface conditions of the foundation rock, anda RCC mix using available aggregate in the rockfill dike, would bethe most appropriate solution for the project.


The new dam is currently under construction (2006 to 2009) andwill be the largest RCC dam (2.06Mm3) in North America.

DAM DESIGN

The new RCC dam will be constructed along the same alignment asthe original concrete faced rockfill dam constructed in the 1960s toimpound the Upper Reservoir. Since the Upper Reservoir is found-ed on top of Taum Sauk Mountain, it has no watershed. TheProbable Maximum Flood (PMF) for the new RCC dam consists ofthe rainfall within the reservoir. Therefore, the hydrology andhydraulic criteria are limited to two major factors, the elevation ofthe crest of the new RCC dam, including freeboard, and the capac-ity of the proposed overflow release structure (spillway).

The overall design basis is to re-build the Upper Reservoir suchthat it will have the same electric generating capacity as the originalUpper Reservoir with a normal pool and overall gross head as estab-lished in the FERC License for the Taum Sauk Plant. This leads toelevations for design shown in Table 1.

RCC MIX

Because of its increased mass and more uniform load distributionon the foundation, combined with water and silt loads on theupstream face, a symmetrical section is more stable and less highlystressed than the conventional gravity dam section for the same loadcondition. As such, a high strength RCC is not required for the sym-metrical section. Londe and Lino suggested the name “hardfill” for

REFURBISHMENT

Conventional concrete

Access road

Backfill

Crest-to-gallery drain

Conventionalconcrete

Bedding mixAsphalt

EL. 1604.5EL. 1601.0 Normal Pool El. 1597.0

Bottom of excavationBedrock

Foundation drain

Groutcurtain

RCC

Drainage gallery

Table 1 – Design elevationsLevel Elevation Basis

Normal operating 1597 Established in thelevel FERC License

Crest of dam 1601 4ft (1.2m) of freeboard

Top of parapet wall 1604.5 Vehicle guide rail

Base of dam Varies but generally in the Suitable rock foundationthe range of EL 1500 at or below foundationand EL 1460 of original CFRD dike

Right, top – Figure 4: View of the old reservoirRight, bottom – Figure 5: Cross section of the new reservoir


REFURBISHMENT

their weak-mix RCC [2]. Based on the hardfill concept and suc-cessful RCC experiences in dams using RCC mixes with challeng-ing materials [3], Rizzo finalized a proposed design comprising asymmetrical section but using a more refined RCC mix, with a morecontrolled gradation than typically used in hardfill dam mixes. TheRCC design strength was set at 1500 PSI.

RCC mix design programThe RCC mix for the proposed dam was developed considering thefollowing factors:• Re-use of the existing Rhyolite rockfill for the coarse and fine

aggregate.• Use of non-commercial fly ash from AmerenUE facilities.• Relatively low required strengths due to the symmetrical cross section.The development of the RCC mix began with performing a Phase Ilaboratory mix design program in the spring of 2006. This programconsisted of 16 RCC mixes utilizing the existing rockfill as aggre-gate. This material was crushed to the proper gradation at a nearbyrock quarry. Class F fly ash from a waste pond at AmerenUE’sMeramec facility was used in most of these mixes. The Phase I pro-gram also included Alkali Silica Reactivity (ASR) testing to deter-mine if the Rhyolite aggregate is potentially expansive. The resultsof the Phase I program indicated that the non-commercial fly ashcould be used to produce RCC, the Rhyolite was potentially expan-sive despite the presence of the Class F fly ash which mitigated someof the reactivity, and an RCC mix consisting of 200 pounds ofcementitious content (cement and fly ash) and 3600 pounds ofaggregate will produce the required engineering properties (i.e., yielda compressive strength in excess of 1,500 psi after one year and aunit weight in excess of 146 pounds per cubic foot).

The RCC Mix design program continued with a Phase II programconsisting of the construction of an RCC test pad using the samematerials with full scale construction equipment. The Phase II pro-gram was conducted in November 2006 and included saw cuts intothe RCC test pad to determine the quality of the RCC. The resultsindicated that the mix design recommended after the Phase I pro-gram was appropriate for the construction of the RCC dam.

Detailed mix design studies using various cement, fly ash andmoisture contents were carried out to determine the appropriateRCC proportions. Aggregate extracted from accessible locations inthe existing dike were crushed to produce usable aggregate for labtrial mixes. Concurrently to the lab trial batches, a comprehensivemortar bar expansion test program involving fly ashes of differentsources and qualities was performed to find options to mitigateAlkali-Silica Reaction (ASR) in the potentially reactive rhyolite.Based on initial lab results, a baseline cementitious content of 200Lbs/CY at 50% ash content was selected for full scale trials.

Two full-scale test sections of about 1500CY (1147m3) each wereplaced prior to dam construction. The first test section was placedin December 2006 while the second was built in August 2007. The

test sections pursued a variety of objectives related not only to mixdesign but also to RCC production and construction, such as aggre-gate crushing, lift joint treatments, bedding mix type and facing sys-tems. Both test sections provided valuable lessons, which helped torefine the mix proportions, improve dam design and make the con-struction process more efficient. Based on acceptable results, damconstruction started in October 2007 using mix 100+100 (C+FA).Available test results indicate that RCC placed in the dam complieswith design requirements.

Test sectionsTwo RCC test sections were built for the Taum Sauk Upper Reservoirproject. While the focus of Test Section I was mainly on materialsand RCC design issues, the Test Section 2 (Production Test Section)also intended to demonstrate and test means and methods proposedby the Contractor for dam construction. A brief description follows:

Test section I (design test section)The primary goal of test section I was to demonstrate that an accept-able, design-conforming mix could be produced using the challeng-ing RCC components available for the project. Another criticalobjective was to demonstrate that Meramec pond ash could beextracted, processed and accurately fed to the mixing plant. Besidesthese relevant objectives, the test section also pursued objectives typ-ical of RCC test sections, such as lift joint quality evaluation, bed-ding mix type selection (mortar vs. concrete bedding mix), andfacing system evaluation. This full-scale RCC placement used crush-ing, mixing and RCC placing equipment typical of small to mediumsized RCC projects.

In early December 2006, about 1500CY (1147m3) of RCC wasplaced using mixes 80+120 and 100+100. Both mixes showedacceptable fresh mix properties, and mechanical properties resultedwell above design requirements. On this basis, mix 80+120 wasselected for the next phase. At the time test section I was built, thefacing system intended to be used for the dam was concrete curbs.For that reason, one face of the test section was built with thismethod; however, cracking experienced in the curb face and sched-ule concerns related to long waiting times for the curb to be able toreceive RCC prompted a design modification to formwork.

Test section 2 (production test section)The primary goal of the production test section was to demonstratemix performance with available materials produced, crushed, trans-ported and delivered with the equipment deployed by the Contractorfor dam construction. Another critical objective was to demonstratethe capability to produce an acceptable upstream face with concreteplaced against inclined formwork achieving an intimate contact withthe RCC mix. As mentioned above, the facing system of the damwas changed from concrete curbs to conventional concrete placedagainst forms (Figure 9). The start of the RCC placement on the

Above and top right – Figures 6 and 7: Foundation preparation workBottom right – Figure 8: Test pad 1 – aggregate bin feeder (left) and place-ment of the base pad (right)


dam was contingent to the quality achieved during this test section.Placement in the test section started mid-August 2007, using mostly

mix 80+120 (C+FA); however, advantage was taken of the initial liftsto try mixes with increased ash content (80+140). The work plancontemplated the placement of 12 lifts of RCC; this section heightallowed for one formwork jump, which was a required test forapproval of the formwork system proposed by the Contractor.

Two types of bedding mix were evaluated during construction ofTest Pad I: sand mortar and !” MSA concrete mix. Both mixes per-formed well and produced well-bonded RCC lift joints. Also, obser-vations made during placement showed that mortar sand was a moreuser-friendly product than concrete; however, the consensus aftervisual evaluation was that the concrete bedding mix produced a supe-rior joint. Figure 10 depicts wire cuts of RCC with bedding mix andwithout bedding mix. In general, the cuts revealed a well compactedRCC mix with a good particle distribution throughout the mass andvery little segregation. On the non-bedding wire cut, segregation alonghigh maturity lift joint lines was more pronounced, but overall qual-ity was acceptable. Interface between RCC and conventional facingconcrete at the w/bedding side, which represents the standard case on

the dam, was considered good. Based on these results, clearance forplacement on the dam was received early October 2007. Placementstarted on 10 October 2007 using mix 100+100 field densities, gra-dation, and compressive strength of the RCC placed on the dam thusfar comply with project specifications and design requirements.

CEMENTITIOUS CONTENT, AGGREGATES ANDFLY ASH COMPONENTS

Figure 11 shows the gradation of truckload size samples extractedfrom accessible places in the rockfill dike scalped at 3 inches.

Aggregate for the initial lab work was produced at a commercialcrusher, which consisted of a primary jaw crusher and a cone crush-er as a secondary crushing stage. Figure 12 depicts the rockfill mate-rial before crushing. At the crushing plant, aggregate was separatedin two aggregate groups (1 1/2” to 1/2” and <1/2”) and additionalscreening was necessary at the lab in the coarse fraction to achievean acceptable gradation. Figure 13 shows a close-up of the twoproducts obtained at the crushing plant.

Originally, the crushing scheme for dam construction used a basic,

REFURBISHMENT

100.0

90.0

80.0

70.0

60.0

50.0

40.0

30.0

20.0

10.0

0.0

Calc. combined G radation

TS specs lower limit

TS specs upper limit

Actual G radation Dec 2-06

100 10 1Size (mm)

0.1 0.01

1” 3/4”3” 2” 11/2” 1/2”3/8” #4 #8 #16 #30 #50 #100 #200

Concrete aggregate gradation 0.90

0.80

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0.10

Aver

age

leng

thex

pans

ion

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0 2 4 6 8 10 12 14Days immersed in 1 N NaOH solution

Threshold indicative of deleterious behavior

Threshold indicative of Innocuous behavior

0.30

0.25

0.20

0.15

0.10

0.05

0.000 10 20 30 40 50 60

Fly Ash replacement (% by weight)

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Class C Fly Ash (Rush Island)

Threshold indicative ofdeleterious behavior

Threshold indicative ofinnocuous behavior

10 days

5 days

51014Series 4

100

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24” 12” 1”3/4”4” 3” 2”11/2” 1/2”3/8” #4 #8 #16 #30 #50 #100 #200

Load#1

Load#3

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Load#15

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Load#6

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Load#10

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Load#16

1000 100 10 1 0.1 0.01

Concrete aggregate gradationcombined minus 3”

Size (mm)

Top row, from left to right – Figure 9: Conventional facing concrete against formwork, test section II; Figure 10a and b: Wire cuts in production with testsection, with bedding mix (left), and no bedding (right). Above, left – Figure 11: Gradation of truckload size samples; Above, right – Figure 12: Rockfill samplesbefore test crushing; Figure 13: Coarse and fine aggregate crushed for lab mixes

Below, left to right – Figure 14: Typical gradation curve produced during test pad I; Figure 15: Expansion test (ASTM C1260) for Taum Sauk Rhyolite;Figure 16: Mortar bar expansion vs class C fly ash replacement


REFURBISHMENT

two-stage crushing plant. However, after the crushing during the con-struction of the test section I, it became evident that a tertiary crush-er was required to get an acceptable gradation. On this basis, tertiarycrusher was included as required equipment in the specifications.

As frequently seen in projects using mixes similar to the type usedin Taum Sauk, preliminary specs considered achieving the combinedRCC gradation by using a combination of only two aggregategroups (11/2” to ¾” and < ¾”). Based on the acceptable resultsobtained during the Test Section I, the two aggregate groupsapproach remained in the specifications. The typical curve producedduring the first test section is depicted in Figure 14.

In addition to the high fines content in the existing dike, the rhyo-lite on site has a propensity to Alkali-Silica Reaction. To confirmASR potential, a series of mortar bar expansion tests were conduct-ed. Figure 15 depicts the results of ASTM C1260 mortar bar expan-sion tests indicating potentially deleterious behaviour of the rhyolite.

The test program included tests with Class C Fly Ash and Class FFly Ash. Figure 16 shows that Class C fly ash was not effective miti-gating ASR and showed a “pessimum” effect at 30% ash; that is, thisamount of ash actually increased expansion. Conversely as depictedin Figure 17, class F ash was very effective at controlling ASR. Atabout 25% ash, the expansion is almost completely suppressed.

Commercial fly ash is available in the project area, however, theOwner operates Meramec Plant, a coal fired power station locatedabout 90 miles from the project. Some years ago Meramec plantproduced class F ash, which was sluiced and stored in a pond nearthe power plant. Rizzo has experience producing RCC with simi-lar ash for use in the Saluda Dam Remediation Project in Columbia,South Carolina, which led to a proposal for using the sluiced pondash. Field investigations revealed that the ash quantity was enoughto cover project needs and that the quality complied with ASTM C618 requirements. Once lab testing confirmed acceptable physicaland chemical properties, additional lab mixes using Meramec fly ashwere prepared to evaluate ash performance in the actual RCC mix.

Extraction and handling of the Meramec pond ash was tried full-scale during construction of Test Section I. The original ash pro-

cessing plan contemplated wet screening to break lumps and removeimpurities and a hydraulic classifying system was used (Econosizer)to separate particle sizes by decantation to produce fine high quali-ty ash. After processing, the ash was deposited in a sedimentationpond, to be later excavated and placed on the ground for furtherdewatering. One problem encountered was that the ash retainedwater longer than expected. Initially it was foreseen that in 24 hoursash water content would be at a level where ash could be easily han-dled; however, in reality it took several days for the ash to be readyfor hauling and handling. At the jobsite, additional handling andspreading was required to bring moisture to a point where it couldbe accurately fed to a continuous mixing plant. It was found that“plowing” the ash with a Rototiller or agricultural disc was one effec-tive way to bring moisture to manageable levels. The valuable lessonslearned during the test pad helped to modify the overall approach toash exploitation and helped to develop systems to feed the ash to theRCC plants accurately. Although extraction costs increased, utiliz-ing Meramec ash still proved feasible due to the additional ash stor-age capacity opened for use at the power station in the years to come.

RCC mixesThe initial set of mixes prepared in early 2006, are presented in Table2. This matrix included mixes with different cementitious contents,different ash types and cement only mixes. Also, different watercontents were investigated and, based on test results, workability,and mix appearance, a water content of 200 lbs/cy was selected asthe baseline value. In general, Vebe times for these mixes were above30 seconds. Based on accelerated compressive and indirect tensilestrength results (Figure 18) and the fact that mixes with 50% ashshowed acceptable workability performance, a cementitious contentof 200 lbs/cy using that ash content was selected as baseline. Thus,the preliminary mix selection resulted in the following proportions:100+100+200 Lbs/CY (Cement+Ash+Water).

In August 2006, three additional mixes with constant cementi-tious content (200 lbs/cy) but different cement/ash ratio were added.The purpose of these mixes was to evaluate performance ofMeramec Class F ash available at an economical distance from thejobsite. This additional set included the following proportions:80+120, 90+110 and 100+100 (C+FA). Strength gained over timefor all mixes with Meramec Ash complied with design requirementsand, based on these results, mixes 80+120 and 100+100 were select-ed for full-scale trial in the Test Sections.

For more information visit www.rizzoassoc.com

References[1] Forensic Investigation and Root Cause Analysis, Dec. 14, 2005Incident. Paul C. Rizzo Associates. Feb 2006.

[2] The Faced Symmetrical Hardfill Dam: A New concept for RCC. Londe, P.& Lino, M. International Water Power Dam Construction, Feb. 1992, 19–24.

[3] The Safest Dam. M. Stevens, J. Linard. Journal of HydraulicEngineering/ Vol. 128/ February 2002.

[4] RCC Mixes and Properties Using Poor Quality Materials ConcepcionDam. L. Gaekel and E. Schrader, Roller Compacted Concrete III. ASCE, 1992.

Table 2. Mix matrixTotal C+F 0% 30% 50% 70%

Class F Class C Class F Class C Class C

100 100+0 50+50 50+50

150 150+0 105+45 105+45 75+75 75+75 45+105

200 200+0 100+100 100+100

250 125+125

300 150+150

10 20 30 40 50 600

0.30

0.25

0.20

0.15

0.10

0.05

0.0010 20 30 40 50 600

0

0

0

0

Fly Ash replacement (% by weight)

14 days(End of std. test)

Class F Fly Ash (Indiana)

Threshold indicative ofdeleterious behavior

Threshold indicative ofinnocuous behavior

10 days

5 days

d ( d

51014

Note: Mix 80+120 does notinclude lifts #11 & #12

100 + 100test pad

80 + 120test pad

1000100101

Acceleratedcuring

Age (days)

Accel. curing

Mix 100+100 test padMix 80+120 test padMix 80+120 test pad

Mix 100+100 test accel.100+100 smooth80+120 smooth

4500

4000

3500

3000

2500

2000

1500

1000

500

0

IWP& DC

Key datesDam failure – 12/14/2005Ameren announced rebuild – February 2007FERC approved rebuild plans – August 2007Selection of Contractors – December 2007Construction began – September 15, 2007RCC placement began – October 10, 2007Total amount of RCC to be placed – 2.06Mm3

Scheduled construction completion – Fall 2009

Key players and contractorsAmerenUE – Owner/Client is a subsidiary of St. Louis based Ameren Corporation.

Federal Energy Regulatory Commission (FERC) is the governing regulating body.

Paul C. Rizzo Associates, Inc. is the Engineer of Record and Construction Manager.

Ozark Constructors, LLC is the main contractor for rebuilding the Upper Reservoir.Ozark Constructors is a venture partnership formed by ASI Constructors, Inc. andSt. Louis-based Fred Weber, Inc.

Above – Figure 17: Mortar bar expansion vs class F ash replacement; Figure 18: Compressive strength vs age mixes 100+100 and 80+120 test pad I

• Impermeable

• Flexible

• Resistant to settlements

• Installed quickly, also underwater

• Durable

• Applicable to all types of structures

• Environmentally friendly

• Efficiently monitored

GEOMEMBRANES ARE:

Sar Cheshmeh, Iran 2008 - Stage II C completed. Exposed PVC geomembrane to waterproofthe raising of a 1 km long tailings dam. Anchorage by welding to PVC geomembrane strips

embedded in porous concrete curbs (patented Carpi system).

CARPI SYNTHETIC GEOMEMBRANES HAVE STOPPED LEAKAGE IN 80+ DAMS

Since 1963

1,200+ projects completed. Design and supply of waterproofing systems fordams, canals, hydraulic tunnels, reservoirs. Dry and underwater installation.

CARPI TECHCorso San Gottardo 86 - 6830 Chiasso - SwitzerlandPh. ++41 91 6954000 Fax. ++41 91 6954009www.carpitech.com e-mail: [email protected]

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Vibrating Wire Piezometersfor Dam Monitoring

High accuracyISO 9001:2000 qualityExcellent long-term stabilityFrequency output allows long cable lengthRugged, reliable designs suited for adverse conditions

•••••

TheWorld Bank has recently approved major projects inAfrica andAsia, along with rehabilitation projects in Eastern Europe. Projects range from small local plants and rehabilitation of existing facilities to multipurposetransnational projects and pumped storage. Consistent with industry-wide growth trends, Bank approvals for hydropower have risen from $250 million/year in 2002-04 to $500 million/year in 2005-07 and more than $800million in 2008. Forty-four hydropower projects approved since 2003 support almost 9700 MWof capacity.

Scaling up hydropower is not limited by physical or engineering potential.The challenges lie in defining hydropower’s strategic value in each country/basin and managing risks.This requires careful attention to projectpreparation and supervision as well as improving the enabling environment.This in turn requires adequate resources, knowledge and skills across multiple stakeholders.

While driven by regional operations, the overall hydropower program is coordinated by a small team in the anchor Energy,Transport andWater (ETW) Department of the Sustainable Development (SDN)Vice Presidency.The team is managed by the Sector Manager of theWater Unit (ETWWA), and overseen by the Sector Director for Energy,Water andTransportation and the Energy and Mining, andWater Sector Boards.The hydropowerteam works closely with the other departments of the SDN, reflecting the basic multi-disciplinary nature of hydropower development and operations.

TheWorldBankanchorunit is seekingtostrengthen itshydropowerteamwithfull-timededicatedexperts tomeetgrowingdemandandopportunity.DutiesandAccountabilities:As a critical member of the Bank’s core hydropower team, the selected candidate will play a key role in helping guide and implement the Bank’s hydropower operational strategy.The successful candidate will report to theSector Manager (ETWWA) and take guidance from the department team leader for hydropower. Responsibilities will include:a)Operations:• Provide specialized technical inputs and handling institutional and implementation issues related to investment operations for effective hydropower development and management at the river basin and country levels. •Work

intensively with Bank teams, country teams, clients, partners and the private sector to lead and/or provide expert judgment on feasibility and other studies, consultations and dialogue.• Serve as peer reviewer/advisor on hydropower-related initiatives and corporate risk projects.Addressing operational queries on an as-needed basis, including enhancement and other quality-related tasks for hydropower

projects within the Bank.b)Hydropowerpolicyandprogrammanagement:• Build awareness of the role of hydropower among country management and other sector anchor assessment groups within the Bank.• Provide strategic and policy leadership for the sector, and in coordinating implementation of the Bank’s hydropower business plan.• Lead the Bank’s knowledge management responsibilities to build capacity both inside and outside the Bank.• Lead input to hydropower aspects of corporate initiatives and management queries• Serve as spokesperson for the Bank in external forums, as appropriate.c)Analytical Initiatives:• Lead and/or participate in ETWsponsored analytical work related to hydropower as guided by the hydropower business plan.• Identify strategic issues and priority economics and sector work to support continuous improvement in the sector.

SelectionCriteriaMaster’s degree in a field related to hydropower development and/or water management and minimum 8, preferably 10 years of relevant experience. Formal training or equivalent in one or more of the following areas:• Engineering •Water resources management/hydrology (including operations modeling) • Energy • Natural resource economicsMinimum of 5 years field based experience in hydropower development and implementation such as in planning, feasibility studies, design, project supervision and operations, preferably in developing countries.In depth understanding of sustainability issues of hydropower development and actions necessary in planning, design and implementation to ensure social, environmental, economic and financial sustainability, includingindustry good practice standards and international policy issues and debates.

Interestedcandidatescanapply throughtheWorldBankwebsite (www.worldbank.org/careers - jobnumber:082579)where therelevantpositiondescription isalsoavailable.Theclosingdate forapplications isSaturday,February28,2009.

TheWorldBankGroupiscommittedtoachievingdiversityintermsofgender,nationality,cultureandeducationalbackground.Individualswithdisabilitiesareequallyencouragedtoapply.Allapplicationswillbetreatedinthestrictestconfidence.

TheWorldBank'sTalentSearch is completingan international search to identifyqualifiedprofessionals forthe followingposition:Senior Hydropower Specialist - Washington, DC


REFURBISHMENTDAM SAFETY

as far as possible, dangers and damage resulting from the existenceof the installation, from insufficient maintenance or from the effectsof war.”

Based on this law a dam safety regulation was established. Thepresent dam safety regulation has been in force since 1 January 1999,and is a revision of former regulations (Mouvet et al., 2001). Theapplicability of the dam safety regulation to a specific dam is basedon geometric criteria (dam height and reservoir volume) and thedamage potential in the downstream region (inundated area).

The regulation defines the duties of the different parties involvedin dam safety, i.e. dam safety authorities, dam owners, dam engi-neers, and dam experts. To facilitate the application of the presentdam safety regulation, the following guidelines were issued by thedam safety authority:

1. Criteria for dams subjected to dam safety regulations.2. Structural safety of dams.3. Safety of dams against floods.4. Safety of dams against earthquakes.5. Monitoring and maintenance of dams.

THE modern era of dam construction in Switzerland start-ed some 135 years ago and came to a virtual standstill inthe 1970s. Since then very few new large dams have beenbuilt. However, two major arch dams have been heightened

and several dams have been rehabilitated. The average age of theexisting large dams is about 50 years (Figure 1). Typically, the con-cession period for hydro power projects is 80 years; therefore, sev-eral of the older power plants – mainly run-of-river plants – havebeen rehabilitated for the renewal of the concession. The expectedservice life of the rehabilitated power plants will be 160 years. Theymust satisfy the current design criteria and safety standards.

Besides ageing, the main concerns are flood and earthquake safetywhere safety criteria apply today, which were not applicable at thetime of construction of most existing storage dams. The prerequi-site for a long service life is the structural safety of the dams andappurtenant structures.

As a rule of thumb, the service life of a dam is as long as propermaintenance can be guaranteed. This means the service life can bevery long. However, this will not be the case if a dam is no longermaintained and monitored, as is demonstrated by the 272m highEnguri arch dam in Georgia, which was not maintained during civilwar and unrests at the time of independence in the early 1990s. Thisdam – the world’s highest arch dam – has shown that the safety ofa dam may deteriorate very fast and even a new dam may becomepotentially unsafe within a few years.

The service life of a well-designed, well-constructed and well-maintained and monitored embankment and concrete dam caneasily reach 100 years. But some elements such as gates and valvesmay have to be replaced after 40 to 50 years. The service life of elec-tro-mechanical equipment and electronic control units is much short-er and some components may have to be exchanged as frequentlyas office computers as they may become technologically outdatedand maintenance may no longer be available.

In the present paper the integral safety concept for large dams isdiscussed, which includes four major elements: structural safety,monitoring safety, operational safety, and emergency planning. Thefirst three safety elements are well-known. However, much less isknown about emergency planning, because alarm systems and evac-uation of the population are often under the control of military orcivil defense authorities. The reason for this is that dams are possi-ble targets in case of war and terrorists are interested in targets withhigh damage potential.

DAM SAFETY IN SWITZERLAND

Legal and administrative aspects of dam safetyThe Swiss Federal Law Regarding Water Police of 22 June 1877stipulates: “The Federal Council will ensure that the necessary stepswill be taken with existing and future storage installations to avoid,

Dam safety is an integral concept,which comprises structural safety, damsafety monitoring, operational safetyand emergency planning, writes MartinWieland and Rudolf Mueller

Dam safety, emergency actionplans and water alarm systems

Figure 1: Grande Dixence gravity dam with a height of 285m, completed in1961, is the world’s highest concrete dam (top). The 250m high Mauvoisindouble curvature arch dam completed in 1957 (bottom). Both dams havebeen in uninterrupted use for some 50 years.

The supervision of the larger dams, i.e. dams with an impoundinghead of more than 25m, or dams with an impounding head of morethan 15m and a storage capacity of at least 50,000m3, or dams withan impounding head of more than 10m and a storage capacity of atleast 100,000m3, or dams with a storage capacity of at least500,000m3, is carried out by the federal dam safety authority whichemploys specialised dam engineers. The safety of small dams is theresponsibility of the cantons (provinces).

The safety authority examines and approves new dam construc-tion projects, as well as projects to rehabilitate existing dams.Therefore, the owner has to submit the project drawings, the analy-sis and design reports, and the results of the geotechnical and hydro-logic investigations to the authority for approval. The constructionwork may not start before approval of the final design has been given.

During construction it performs inspections and checks compli-ance with the approved plans. All findings are placed on record.

The initial impounding of a dam requires the authorisation of thedam safety authority.

During operation of the dam the authority supervises the surveil-lance organisation of the owner, of the experienced engineer and ofthe experts.

The reports of the experienced engineer (yearly) as well as theexpert’s appraisals (five-yearly) on condition and behaviour of thedam are immediately notified to the dam safety authority.


If monitoring or inspections call for remedial actions, they haveto be carried out immediately.

Basic elements of dam safety conceptThe two main goals of every safety concept are the minimisation ofall risks, and the mastering of the remaining risk in the best possi-ble way (Biedermann 1997). To reach these goals a comprehensivedam safety concept was introduced in Switzerland comprising thefollowing elements: (i) structural safety, (ii) dam monitoring and dammaintenance, and (iii) emergency planning.

i) Structural safetyMinimization of the risks calls for an appropriate design and con-struction of the dam. This means that the design (design criteria anddesign concepts) should be periodically reviewed to ensure that thestructural safety will be guaranteed according to the state-of-the-art.Figure 2 shows the Sefid Rud buttress dam in Iran, which experi-enced much stronger earthquake actions than originally assumed inthe design. The seismic design criteria and methods of dynamicanalysis used for the design of the dam are considered obsolete today.

ii) Dam monitoring and dam maintenanceRisks can be minimized but never totally eliminated even if a damhas been designed and constructed according to the latest state ofknowledge. Therefore, it is necessary to detect any signs of abnormalbehaviour, damage, deficiencies in structural safety, and new types ofthreats and hazards etc. as quickly as possible, so that corrective mea-sures can be taken in time. In order to achieve this, periodic inspec-tions of the dam, as well as periodic safety evaluations, are needed.The purpose of the periodic inspections is to monitor the actualbehaviour of the dam. The periodic safety evaluations are used forcontrol of the long-term behaviour as well as for verification of thestructural safety. The dam surveillance system used in Switzerland isshown in Table 1. The responsibilities of the different parties involvedin dam surveillance and dam safety monitoring are as follows:

• Dam owner: The dam owner has to maintain the dam in goodcondition. For this purpose he establishes an organization to mon-itor and maintain the dam. The technical staff of the dam ownerperforms regular visual inspections and measurements on a weeklyor monthly basis. Automatically registered measurements arechecked monthly by manual readings. The dam technician checksthe operational readiness of the outlet gates at least once a year.The results of the observations and measurements are forwardedto an experienced engineer appointed by the dam owner.

• Experienced engineer: The experienced engineer checks the mon-itoring results on a continuous basis, performs an annual inspec-tion of the dam and compiles his interpretation of the dam’sbehaviour and condition in an annual report. The engineer mayalso act as a consultant to the dam owner.

• Experts: Larger dams with an impounding head of at least 40m,or 10m with a reservoir capacity in excess of 1Mm3, must under-go a comprehensive safety review by nominated experts every fiveyears. The experts, being civil engineers and geologists, are recog-


Table 1. Structure of dam surveillance system in SwitzerlandLevel Responsibility Activities Reports

1 Owner (dam safety Regular inspection of condition (by visual observations) and behaviour Monitoring records and test protocolsengineer, technical staff) (by measurements). Tests of spillway and bottom outlet gates.

2 Experienced engineer Analysis of the measured data and observations. Annual inspection Yearly report on condition and on(civil engineer) of the dam. measured behaviour.

3 Experts (civil engineer Inspection and appraisal of the dam safety every five years. Report on condition and long-term behaviour.and geologist) Analysis of special safety related questions.

4 Dam Safety Authority On-site inspection. Review of the annual reports and the expert’s Interventions if measures have toappraisal. Verification of the implementation of the necessary measures. be implemented.

Figure 2: Repair and strengthening of Sefid Rud buttress dam in Iran, whichwas damaged during the magnitude 7.5 Manjil earthquake of 21 June 1990:downstream view of dam (top), strengthening of all 25 buttresses with rockanchors with a capacity of 100 MN per block (bottom)



nized specialists in dam engineering and are appointed by the ownerin agreement with the dam safety authority.• Dam safety authority: The dam safety authority reviews the annual

reports of the experienced engineers as well as the five-year appraisalsof the experts. It also carries out on-site inspections and verifies thatthe recommendations stated in the annual report and five-yearreports are observed and the necessary measures are implemented.

iii) Emergency planningIn case of an identified hazard to the dam the situation is managedaccording to the emergency planning concept. It is important that themeasures to be taken have been prepared in advance. These measuresconsist of a strategy and of emergency plans. The potentially floodedarea in case of a dam break has to be determined, and the results shouldbe presented in a flood wave inundation map. This map allows evac-uation of the population in the flooded area to be planned. Furtheremergency planning measures include the installation or at least thespecification of the alarm devices, and the organizational provisionsfor ensuring the evacuation of the population. The emergency strate-gy defines three danger levels. Specific technical and operational pro-visions as well as emergency actions are assigned to every danger level.

DAM SAFETY, CONSEQUENCES OF DAM FAILURE,AND MEASURES FOR RISK REDUCTION

Today, a comprehensive safety concept is used for projects withlarge damage potential such as large storage dams, nuclear facili-ties etc. For dams it includes the following key elements: (i) struc-tural safety, (ii) dam safety monitoring, (iii) operational safety andmaintenance, and (iv) emergency planning. Usually design engi-neers are primarily concerned with structural safety; however, forcritical infrastructures like large storage dams, safety goes beyondstructural safety and must include items (ii) to (iv) listed above.Operational safety, which is not considered explicitly in the Swissdam safety concept, is an important issue, which has to be con-sidered. A typical example is the failure of the upper reservoir ofthe Taum Sauk pump storage scheme in the US, which failed inDecember 2005 (see page XX).

The consequences of dam failure are: loss of life (reduction of lossof life is the top priority of emergency planning); environmentaldamage; property damage in flood plain; damage of infrastructure;loss of power plant and electricity production; socio-economicimpact; political impact, etc.

These consequences can be reduced by a number of structural andnon-structural measures. The structural measures are mainly relat-ed to the safety of the dam, i.e. flood safety, earthquake safety, andsite conditions. The non-structural measures include the following:safe operational guidelines for reservoir under normal and abnor-mal operational conditions; implementation of emergency actionplans; implementation of water alarm systems; training of person-nel; lowering of reservoir level in case of safety concerns; periodicsafety checks; engineering back-up to cope effectively with abnor-mal and emergency situations; land use planning (political decision);insurance coverage, third party liability coverage (protection fromeconomic losses), etc. The non-structural measures are often moreeffective than structural measures.

EMERGENCY PLANNING IN SWITZERLAND

Emergency procedures include a plan on how to warn the authori-ties and how to alert the population (Pougatsch et al., 1998).

The dam owner must provide a flood wave inundation map show-ing the flooded area, the energy head level and the arrival time ofthe flood wave.

For dams with a storage capacity of more than 2Mm3 a wateralarm system is mandatory in the so-called close zone. This zone willbe flooded within two hours at most. This corresponds to a distanceof about 30km downstream of the dam. The water alarm systemconsists of special sirens that can be activated directly from the dam.It has to be maintained and tested on a regular basis by the dam

owner. In the distant zone – the rest of the flooded area – the alarmis released with the civil defence general alarm sirens and broadcastdirectives. This alarm system is installed and maintained by the can-tons. In the fact, a new generation of sirens are to be installed whichcan operate both as water alarm sirens and as general alarm sirens.

For smaller dams with minor flooded areas the water alarm isreleased using the civil defence general alarm sirens.

The cantons and the municipalities are responsible for the plan-ning and preparation of the emergency directives and for evacuationof the population.

The flood wave inundation maps are used on the one hand foremergency planning purposes and on the other hand to define theapplicability of the regulations to a specific dam. The intensity of theflood wave is defined as the product of the water depth with the flowvelocity and must be assessed with the limit values given in Table 2.

EMERGENCY ACTION PLANS

The main objective of emergency planning is to save lives. The eco-nomical losses of the dam owner and the owners in the flood plaincan be covered by insurance.

Emergency Action Plans (EAP) are intended to help the damowner and operator, and emergency officials to minimize the con-sequences of flooding caused by dam failure or the uncontrolledrelease of water from a reservoir. The EAP will guide the responsi-ble personnel in identifying, monitoring, responding to, and miti-gating emergency situations. It outlines “who does what, where,when, and how” in an emergency situation or unusual occurrenceaffecting the safety of the dam and the power plant. The EAP shouldbe updated regularly and after important emergency events.Basically, the dam owner is responsible for maintaining a safe damby means of safety monitoring, operations manual, maintenance,repair, and rehabilitation.

In an emergency situation, the dam owner is responsible for mon-itoring, determining appropriate alarm levels, making notifications,implementing emergency actions at the dam, determining when anemergency situation no longer exists, and documenting all activities.In the case of an emergency, the dam owner is responsible for imme-diate notification of the authorities, who are in charge of warningand evacuation of the affected population. Warning is performed byspecial water alarm systems as discussed in the subsequent section.The basis for evacuation planning is a dam breach flood wave analy-sis, which shows the inundated area for the worst case failure sce-nario, i.e. the sudden failure of the dam. In addition, the arrival timeof the flood wave, flow velocities and water depth are resultsobtained from such an analysis. As a rule of thumb, it takes abouttwo hours for a flood wave to propagate 30km.

Table 2. Definition of dangerlevels of flood waves(h: water depth; v: flow velocity)Danger levels and Dam safety regulations applyintensity of flooding if danger levels are exceeded

High dangerh > 2m or v·h > 2m2/sec People inside massive buildings, in railway

coaches, in passenger cars, or on campingsites are in danger.

Medium danger2 m ≥ h > 1m or 2m2/sec People inside buildings, in passenger cars≥ v·h > 1m2/sec or on camping sites are in danger.

Moderate danger1 m ≥ h > 0.5m or 1m2/sec People in passenger cars and on camping≥ v·h > 0.5m2/sec sites are in danger.

Low dangerh ≤ 0.5m or v·h ≤ 0.5m2/sec The regulations do not apply.


The EAP consists of several components or tasks, namely:

• Hazard classification – a determination of the types of hazard thatcould affect the safety of the facility. Hazards can be associatedwith natural events and processes (e.g. floods, storms, earthquakes,internal erosion, etc.) (Figure 3), with the operation of safety-rel-evant hydro-mechanical and electro-mechanical equipment (e.g.gate jamming, failure of monitoring equipment, etc), and withdamages caused intentionally by people (sabotage, terrorism, war,etc.).

• Emergency classification – determination of the level of severity ofan incident or unusual behaviour of a monitoring instrument orof a mechanical/electrical part. Three levels have been distin-guished: (i) internal alert, (ii) developing situation, and (iii) immi-nent situation. As an aid for judging the level of severity anassessment matrix can be developed (which may change from onefacility to another one, depending on the dam’s characteristics andthe environment) (Table 3).

Upon discovery of, or after having been notified about, an unusualscenario, two possible situations must be judged, namely whetherexternal assistance is needed and whether there are adverse impactswith a threat to population, structures or environment. The urgencyof the situation is the major factor in classifying the severity of anincident. The following alarm levels and emergency situations canbe distinguished:

• i) The internal alert triggered by an unusual situation can be man-aged and controlled by the dam’s staff. Typical internal alert sce-narios are flood warning prior to receiving information on the sizeof the flood and potential dangers, and also abnormal monitoringresults where readings on certain instruments exceed pre-set safetylimits (e.g. piezometric heads, discharge from drainage facilities ordisplacement of structures).

• ii) A developing situation exists when the observed incident clear-ly tends to turn into a serious threat to the dam’s safety and thepopulation in the downstream area. At this stage it is not yetknown whether the situation can be brought under control.

• iii) An imminent situation has developed when it has become clearthat the progress of the incident or threat cannot be stopped butits consequences can still be mitigated, such as the evacuation ofthe population in danger.

Communication or notification of the incident could be internallyonly or both internally and externally. Externally means communi-cation with local and state authorities, responsible for the executionof emergency actions. Communication can be facilitated by notifi-cation charts, which display the flow of information among con-cerned parties and the executive staff of the facility. Internally, thenecessary measures will be carried out by an Emergency Task Group(ETG), which is composed of members of the operating staff.


Figure 3. Hazards from natural environment affecting dams: Overtopping of Palagnedra dam in Switzerland due to plugging of spillway by floating debris 1978(left); failure of two gates of Shih-Kang weir due to fault movement caused during the 1999 Chi-Chi earthquake in Taiwan (right)

Table 3. Example of hazard matrix forhydro power plant showing hazardsand required protective measures(Emergency classification:A: internal alert; B: developing situation;C: imminent situation)

PROTECTIVE MEASURES

HAZARDS Rehabi- Partial Full Evacuation Post-eventlitation reservoir reservoir evacuation

drawdown drawdown

Natural hazards

Floods A B C

Ice problems A

Earthquake C

Storm and lightning A

Structural hazards

Abnormal A B Cinstrumentationreadings

Spillway gates and C Cequipment failure

Joint failure A C

Differential A B C Cmovement of structure

Embankment piping A B Cor seepage

Electrical/mechanical Afailure and powerplant shut-down

Man-made hazards

Fire A B

Oil or hazardous Amaterial release

Criminal action, B Csabotage, terrorism,acts of war

Human error A



WATER ALARM SYSTEMS

In Switzerland, 65 large dams have been equipped with a wateralarm system. The first systems were installed some 50 years ago.The driving force behind these systems was the military. The objec-tive was to prevent the type of disasters which were observed inGermany, when several large dams were destroyed during WorldWar II. Therefore, the main threats considered were acts of war. Thishas changed over the years.

Technology has developed very fast in recent years and wateralarm systems have to take advantage mainly of the new develop-ments in equipment and communication. The water alarm systemsas such are not changing as the inundated areas remain unchanged.However, with new developments, additional warning equipment(sirens) may be needed.

A problem with triggering a water alarm is the fact that manydams are no longer monitored by the dam owner’s personnel 24hours a day. In remote places, nobody is at the dam site in winter.Therefore, access to the dams during emergency situations is a logis-tical problem. During severe rainfalls or after an earthquake, roadsmay be blocked, etc. Also, in order to prevent false alarms, the sirensare usually not in an operational mode, i.e. they have to be activat-ed when a predefined alarm level is reached. This will take some timeif it has to be done manually. Only when the sirens are operationaland the highest alarm level is reached, i.e. it has to be expected thatthe dam may fail, then a specific acoustic signal notifying a wateralarm is released.

In Switzerland, a distinction is made between the near field of aflood wave, which is defined as the distance the flood wave willtravel in two hours, and the far field beyond that time limit. Thedam owners are responsible for the water alarm equipment in thenear field; the normal ‘civil defense’ sirens are used in the far field.Fortunately, up to now, no emergency has developed where peoplehad to be evacuated. Annual exercises are carried out by the author-ities and the dam owners only and the proper functioning of theequipment is checked.

It is obvious that a water alarm system contributes significantlyto the credibility of the dam owners and the authorities by showingthat they are concerned about the safety of the people living down-stream of large dams.

An example of a leaflet distributed to the population living in thearea in Zurich inundated by the possible failure of the Sihlsee damis shown in Figure 4 together with the two types of sirens used.

CONCLUSIONS

Emergency planning and the installation of water alarm systems inthe downstream region of large storage dams is a must. Even if adam is structurally safe, there are natural or man-made events thatcould cause failure. For emergency planning to be effective, the pop-ulation affected must be involved and informed about what to doin an emergency. The first water alarm systems for dams wereinstalled in Switzerland some 50 years ago.

The Emergency Action Plan (EAP) for storage and run-of-riverfacilities is an efficient dam safety management tool assisting the damowner or operator in the handling of possible adverse impacts thatmay originate at the dam or in its environment. The components ofthe EAP, i.e. hazard identification and classification, ‘unusual situa-tions’ matrix and emergency classification and notification chartspresent clear steps to follow in the case an unusual observation hasbeen noticed requiring corrective or mitigating actions.

The EAP facilitates decision making and streamlines communicationamong the responsible persons. It provides support to the key responseactions to be taken within the dam owner’s organization.

Martin Wieland, Chairman, ICOLD Committee onSeismic Aspects of Dam Design, Poyry Energy Ltd.,

Zurich, Switzerland. Email: [email protected]

Rudolf Mueller, Dam Expert, AF-Colenco Ltd., Baden,Switzerland; formerly Deputy Commissioner for Dam

Safety, Swiss Federal Office for Energy, Bern, Switzerland.Email: [email protected]

This paper was presented at the High-Level InternationalForum on Water Resources and Hydropower, which washeld in Beijing from October 16 – 18, 2008 in connectionwith the 50th anniversary of the China Institute of Water

Resources and Hydropower Research (IWHR)

References[1] Pougatsch H., Mueller R., Kobelt A. (1998): Water Alarm Concept inSwitzerland, Dam Safety, Berga (ed.), Balkema, Rotterdam, Holland.

[2] Mouvet L., Mueller R.W., Pougatsch H. (2001): Structural safety ofdams according to the new Swiss legislation, Proc. ICOLD EuropeanSymposium, Geiranger, Norway.

[3] Biedermann R. (1997): Safety concept for dams: Development of theSwiss concept since 1980, wasser energie luft, 89 Jahrgang, Heft 3-4Baden, Switzerland, pp. 55-63.

IWP& DC

Figure 4. Flood map of Zurich with evacuation directions (failure of theSihlsee dam located some 30 km away from the Zurich) (left); water alarmsiren (above left); general alarm siren (above right)


REFURBISHMENT

remedial works in conjunction with Bachy Soletanche.Primarily, the project required the construction of a slurry cut off

wall from the crest of the dam using a diaphragm wall grab tech-nique to prohibit the migration of groundwater when the reservoiris refilled. A crane-mounted hydraulic grab was considered the mostappropriate method to use, as it maintains verticality and accuracythrough onboard software and detects the slightest of movementduring excavation which is particularly essential when the depth ofthe slurry cut-off wall is 42m.

The installation progresses in stages or ‘panels’ along the lengthof the dam and directly through the existing clay core. A cement ben-tonite slurry mix is pumped into each panel during trench excava-tion which keeps it stable and creates the finished impermeablebarrier. The dam slurry wall is 200m long (with an 800mm width).

The grouting stage of the project firstly requires the installationof a grout curtain wall. This goes into the rock at the dam base toseal the interface between the clay and the rock, and improve theintegrity of the rock itself. The grout will extend 10m into the rock,therefore reaching as far as 55m below the crust of the dam. It ishere where Bachy Soletanche will install the grout tubes using theoverlapping method.

Further grouting is also taking place within a 1.7m diameter brickand concrete lined culvert. It carries water from the reservoir’s draw-down tower into the river on the downstream side of the dam andruns right through the base of the dam’s clay core. It is consideredthat the culvert could also leak when the reservoir is reinstated.Bachy Soletanche is therefore sealing the interface of the culvert andsurrounding clay by grouting around it.

All the remedial work conducted by Bachy Soletanche was com-pleted in November last year, however the project hasn’t gone with-out its challenges. Daniel Barnard, the project’s Contract Managerexplained: ‘It was a very sensitive project in regards to environmen-tal considerations as a nearby river is in close proximity to the site.This required extremely careful coordination on our part in order toavoid contaminating the water with the grout or bentonite fluid usedon site. Flexibility with our design was also key to the process due tothe poor ‘as built’ construction records from 1911. It led to a 3DCAD model of the dam and surrounding ground being designed inconjunction with Black and Veatch which is proving to be anextremely beneficial tool to the design of the project.’

www.bacsol.co.uk

IN the picturesque surroundings of Ebbw Vale, South Wales,Bachy Soletanche Limited is conducting essential remedial worksat the Dwr Cymru Welsh Water owned Lower Carno Dam.Built in 1911, the dam has been plagued with a number of leak-

ages and complications eventually leading to the adjacent reservoirbeing emptied in 2005. Now in order to refill the reservoir, the geot-echnical specialist will construct a slurry wall and provide compre-hensive rock injection grouting to reinforce the dam in a multimillion pound two-phase project.

It was essential to get to the root of the problem, as the reservoirincreases the water supply to the local towns and future develop-ments in the community. However it was only after the reservoir wasemptied that one of Welsh Water’s partners, Black and Veatch, gotthe opportunity to determine a permanent solution to the dam’songoing problems. The firm initially conducted a study to identifythe possible mechanisms for the leakages and after carrying out anintrusive investigation, developed an appropriate design for the

Lower Carno dam

Essential remedial works are being carriedout at Lower Carno dam in Wales, UK

Back on the mend

For the initial phase of the project, Bachy Soletanche installed a slurry cut offwall along the crest of the dam using a crane mounted hydraulic grab

IWP& DC


REFURBISHMENT

FRANCIS turbine runners play a crucial role in convertingenergy from water into mechanical energy. Unfortunatelycracks occur frequently on turbine blades. Research [1] hasindicated that most of the regular cracks are fatigue cracks

where blades have been subjected to cyclic steady stress and vibra-tory alternate stress. The existence of cracks seriously endangers theoperating stability and safety of power stations, so it is necessary tomonitor the initiation of cracks and to master the developing trendof the cracks. However, it is very difficult to find a method that effec-tively monitors the state of the turbines, mainly due to the complexstructure and operational environment of turbine units. As far as theauthors are aware, minimal research exists of the monitoring ofcracks in Francis turbine blades.

Acoustic emission (AE) technique, a passive non-destructive test-ing (NDT) method, is very sensitive to crack and failure of materi-als and structures. It has been widely used for inspection andmonitoring in non-destructive evaluation [2, 3]. This research paperaims to recognize the AE characteristics of fatigue cracks in the bladematerial, and will then compare the characteristics with thosereceived from background noise on site.

EXPERIMENTS

Three-point bending fatigue testHydraulic pressure produces bending stress on the blades when run-ners operate under stable state [4]. Crack signals of a blade materialfrom the three-point bending fatigue test were received in order toobtain their AE characteristics under the bending fatigue loading. Thematerial generally used for blades, 20SiMn, was chosen. The three-pointbend (SENB) specimen was machined according to the ASTM standardE647 [5], i.e. S!W!B=240!60!20 (mm3). The specimen was pre-cracked by electric spark line cutting (8mm length).

The specimen was tested in the load-controlled mode of an Instron8801 servohydraulic test machine at room temperature. The cracklength was measured using the compliance method by a crack open-ing displacement (COD) gauge. The experimental setup is given inFigure 1. Two SR150 AE sensors (50-400 kHz) and two model 2/4/6pre-amplifiers (10K10k- 2M Hz) were chosen. Signal conditioningwas performed by the preamplifiers. The conditioning signal wasfed to the main data acquisition board. The AE parameters andwaveforms were recorded via Physical Acoustics CorporationSAMOS system. All the data were processed by a computer. In addi-tion, the sensors were mounted on the symmetrical positions 50mmaway from the pre-crack line. The interface between the AE sensorsand the specimen was filled with vaseline in order to keep the trans-mission performance of the signal.

The specimen was subjected to cyclic tension-tension loading inthe sinusoidal wave shape with an R-ratio of 0.1. The applied loadrange was determined from the geometry of the test specimens andmaterial properties and remained fixed (maximum 23 KN) through-out the test. In order to reduce the testing time, the loading frequencywas set to 10Hz as it had little effect on fatigue crack growth [6].

Receiving background noiseThe background noise was received from the No. 1 turbine unit ofYantan power station (Figure 2). The rated speed of the unit is 75 r/min,the operating power is 302.5MW and the water head is 55m. The same

Figure 1 Experimental setup

Hydraulic turbine runners are subjected to cyclic steady stress and vibratory alternatestress, which can often lead to cracks on the turbine blades. Research has been carried outon the application of the acoustic emission technique to detect crack signals on the blade

Sounding out fatigue cracks

Figure 2 Receiving the background noise on site

Table 1 Test parameter setupParameter type Instrument set values

Threshold value 42dB

Peak Definition Time 300!"s

Hit Definition Time 600"s

Hit Lockout Time 1000"s

Sample rate 1MHz

Filter on board(low) 20kHz

Filter on board(high) 400kHz

Pre-amplifier gain 40dB

Pre-trigger 50"s

Hit length 1K

AE sensors and acquisition system with the fatigue tests were used.The AE testing parameter setup for the two tests was the same and

is shown in Table 1. The threshold of 42 dB was determined in thefatigue tests, which was just above the background noise level deter-mined using a dummy specimen without a slot when the hydraulicpower supply was turned on.

RESULTS AND DISCUSSIONS

The correlation of the AE amplitude versus loading cycle during thefatigue test is plotted in Figure 3. It shows that the amplitude of cracksignal is mainly concentrated on 68-73 dB, except for a smallamount of signals with 49-53 dB during the initial stage of fatiguetest. Thus, the AE amplitude can be considered one of methods torecognize and extract the crack signal.

The correlation of duration versus energy is shown in Figure 4. Itindicates that the duration is proportional to the energy because theduration reflects the releasing mode of energy. The plot of the dura-tion of the AE events against their energy can be used to monitor theonset of failure. Events with evident higher durations and energies maypredict failure approached. For the specimen, the failure initiates whilethe duration is above 840!s and the energy is above 2500 counts.

The AE characteristics of the fatigue crack signals and the back-ground noise are listed in Table 2. It shows that the AE parametersof the two kinds of signals are very different. The rise time and dura-tion of the crack signals are shorter than those of the backgroundnoise. The amplitude is between 49dB and 74dB, which is lowerthan that in the background noise (90-99dB). The peak frequencyis above 80 kHz while it is below 60 kHz in the noise.

The waveforms and the corresponding spectrograms of both thecrack signals and the background noise are shown in Figure 5. Themaximum amplitude of the noise is 1.5V, which is greater than thatin the metal crack signal, 0.3V. The energy of the background noiseis mainly concentrated on 30-55 kHz while it is concentrated on 60-150 kHz for the crack signal.

Both the AE parameters and the waveforms indicate the differ-ence of the two kinds of signals. The reason is the different mecha-nisms of the two kinds of signals produced. The AE source of theductile blade material is very weak [7], so the amplitude is low.However, the background noise is made up of periodic vibration sig-nals of turbine units, which has a longer duration and rise time anda lower frequency range. As a result, through suitable signal pro-cessing methods, it is possible to extract the useful crack signalswhen the signal-to-noise ratio is lower.

CONCLUSIONS

The AE amplitude range of crack signals of the blade material isbetween 49 dB and 74 dB, but it mainly concentrates on 68-73 dB.The AE energy and duration are useful parameters to embody bladefailure. The failure initiates while the duration is above 840!s andthe energy is above 2500 counts in the tests.

The values of the AE parameters of fatigue crack signals and back-ground noise are very different because of the different producing


mechanisms. The background noise is continuous vibration signal,which has longer duration and rise time and lower frequency rangeand amplitude. As a result, the two kinds of signals can be distin-guished by the AE parameter filtration and the extraction of thecrack signals with the low signal-to-noise ratio.

To summarize, the AE technique could be considered an effec-tive tool to monitor fatigue cracks in turbine runners. The nextstage of this work will focus on the study of a suitable signal pro-cessing method.

Xianghong Wang and Changming Zhu, School ofMechanical Engineering, Shanghai Jiaotong University,

1954 Huashan Road, Shanghai 200030, China*

Hanling Mao, Guangxi Radio and TV University,Nanning 530004, China*

Zhenfeng Huang, School of Mechanical Engineering,Guangxi University, Nanning 530004, China*

REFURBISHMENT

1000

800

600

400

Dur

atio

n(µ

s)1000

Energy (count)2000 3000

72

66

60

54

48

Ampl

itude

(dB)

0.0 0.4 0.8Cycle

1.2 1.6 x105

3002001000 0500Time (µs) Frequency (kHz)

3002001000Frequency (kHz)

1000

0 500Time (µs)

1000

0 500 1000

0 500 1000 3002001000

3002001000

0.2

0

-0.2Ampl

itude

(V)

1

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-1

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itude

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0

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itude

(V)

0.06

0.04

-0.02

0

Ampl

itude

(V)

(a) (b)

(c) (d)

From left to right: Figure 3 – AE amplitude versus loading cycles; Figure 4 – AE Energy versus duration; Figure 5 – Waveforms and FFT spectra of fatigue AEsignal (a) time domain, (b) frequency domain and background noise (c) time domain, (d) frequency domain

References[1] Fisher D, The cause of runner crack and the solutions implement for theXiaolangdi Hydroelectric project, in: Proceedings of the XXIst IAHRsymposium on Hydraulic machinery and systems, Lausanne, 2002, pp. 9-12

[2] Ennaceur C, Laksimi A, Herve C, Cherfaoui M. Monitoring crack growthin pressure vessel steels by the acoustic emission technique and themethod of potential difference. International Journal of Pressure Vesselsand Piping, 2006,83(3):197-204.

[3] Mba D,Hall L D. The transmission of acoustic emission across large-scale turbine rotors. NDT & E International, 2002,35(8):529-539.

[4] Carpinteri A, Brighenti R, Huth H-J, Vantadori S. Fatigue growth of asurface crack in a welded T-joint. International Journal of Fatigue,2005,27(1):59-69.

[5] ASTM, ASTM E647-05: Standard Test Method for Measurement ofFatigue Crack Growth Rates, in Annual Book of ASTM Standard. 2005.

[6] Huth H J, Fatigue Design of Hydraulic Turbine Runners. Trondheim:Norwegian University of Science and Technology, 2005, pp.61-72.

[7] Moorthy V, Jayakumar T, Raj B. Influence of micro structure on acousticemission behavior during stage 2 fatigue crack growth in solutionannealed, thermally aged and weld specimens of AISI type 316 stainlesssteel. Materials Science and Engineering A, 1996,212(2):273-280.

• The authors wish to express their gratitude to Institute of ElectricityExperiment and Yantan water power plant, Guangxi province, for theirassistance in undertaking this investigation. This research is supported by theNational Natural Science Foundation of China under grant number 50465002.

IWP& DC

Table 2: AE Parameters of the fatiguecrack signals and background noiseType Rise time Duration Amplitude Peak Frequency

Crack <290!s <900!s 49-74dB 83-184kHz

Noise <66!s 334!s or so 90-97dB 39-60kHz


SOFTWARE

flaws in that solution can then inform the next, and so on.A case in point would be the recent scheme at Glendoe in

Scotland, where First Minister Alex Salmond closed the dam gate inSeptember 2008. Glendoe will play a crucial role in meetingScotland’s and the UK’s renewable energy targets, but EnergyMinister Jim Mather warned that ‘we are unlikely to see much inthe way of further large scale developments.’

This is not to say large scale opportunities don’t exist, but that we

Getting to the bottom of itThe availability of grant funding, improvements in the planning process and a steadilyimproving public acceptance are making more hydro schemes viable – but finding sitescan still drain resources. A new approach to site identification dramatically reduces theneed for speculative site visits, and opens the market for small and micro hydrocustomers. Nick Forrest gives IWP&DC an insight into the development of Hydrobot

READERS will be aware of the opposition to large hydrodevelopments from ecologists and the debate that hasopened in the environmental community. We have a trade-off between the environmental, social and economic bene-

fits of a new renewable energy installation, versus the environmentaland cultural impacts of the structure. The ‘best’ answer at any onetime would be one reached by a healthy democratic process whereopinions on each side are heard and evidence assessed equally. The

Hydrobot is the model used by Nick ForrestAssociates to model Scotland’s hydro potential


may need to lay off the valley-flooding for a bit. In five or ten yearsit may be time to look again.This puts the spotlight on small hydro (up to 5MW or so) where

small impoundments or even run-of-river schemes will suffice.Engineering consultancies across the world are dusting off theirultrasonic transducers, but it seems many small landowners are putoff by the upfront cost of a pre-feasibility study: £500 (US$765) toperhaps be told there’s no potential at all. And the poor old devel-opers are having to visit ten unsuitable sites for every good one.Then there’s the planning process, costs of development and oppo-

sition from fisheries which, in Scotland, mean all hydro is presumedguilty until proven innocent. This is not the route to JimMather’s ‘sus-tainable and profitable future in smaller and micro hydro schemes’.Enter Hydrobot, a new approach to hydro site identification

which could solve many of these problems. Hydrobot is a combinedgeographical information system (GIS) and financial assessment tool,designed to mimic a quarter of a million hydro engineers trampingup and down the hills of Scotland finding hydro sites. The modelfirst hit the headlines when it was commissioned by the Forum forRenewable Energy Development in Scotland (FREDS), on behalf ofthe Scottish Government, to assess the nation’s remaining hydropotential. The resulting Scottish Hydropower Resource Study hadthe remit of identifying the main barriers to hydro development inScotland [see p12]. Now that the government has verified hydro’scontribution to renewables targets could be significant, it is com-mitting resources to tackling the barriers to hydro development.Confidence and further competitionwithin the industry should bring

prices down, but developersmay still waste valuable time and resourcesporing over large estates. Hydrobot can be applied to any land areawithin Scotland and the top sites supplied to those developers.

DEVELOPING HYDROBOT

Hydrobot was first conceived as a university project, and operatedas a series of processes rather than a single model. It was initiallyused to analyse the catchments of the North and South Esk nearEdinburgh. After this, the model followed two very different devel-opment paths. In 2007 I qualified for the Starter for 6 initiative,which is run by the National Endowment for Science, Technologyand the Arts (NESTA). Starter for 6 is an enterprise support project,and provided funding that allowed me to establish a web portal forHydrobot, and to develop the model for micro hydro applications.When FREDS launched a competition in late 2007 to survey

Scotland for hydro potential, Hydrobot was an obvious contenderas it was already running, albeit for micro hydro. Developing themodel to cover the whole of Scotland and bolting on other requiredfeatures was relatively fast and economic, compared to what itwould have taken any other consortium to do the same job. Costingand calibration was directed by Black & Veatch, with environmen-tal and grid impacts analysed by SISTech Ltd.Needless to say, other development was put on hold during the

undertaking of the Scottish Hydropower Resource Study. As a resultthe online version only went live on 29 October 2008. It will pri-marily identify micro hydro schemes to begin with, though the otherfeatures used in the Scottish study that model larger schemes will bephased in over time.Meanwhile the core Hydrobot model is being used and developed

for clients requiring a larger or more specific service. The basic ser-vice will cost £35 (US$54) for a 1km2 tile, including VAT. The clientreceives a pdf report including a map illustrating the layout of thescheme, and a table summarising the size, costs and profits for eachidentified scheme. There could be several schemes within that area.By comparison, a traditional hydro pre-feasibility study, includingsite visit, would cost between £3-600 (US$459-918).

HOW TO BUILD AN ARTIFICIAL ENGINEER

So how does it work? Obviously the exact algorithms are commer-cially sensitive, but here’s an outline. Hydrobot is based on a surfaceflowmodel derived from elevation data in 10m x 10m squares across

the whole of Scotland. Every watercourse has been modelled to give21 exceedence levels on the annual flow duration curve at any point.The accuracy of the predicted flows has been tested against measuredflows away from established gauging stations, and also examined bythe Scottish Environmental Protection Agency (SEPA).A range of grid connections are possible, depending on the loca-

tion and size of the scheme:

• Domestic connection at 240V or 400V.• Connection to an existing 11kV line.• Connection to the 33kV network by installing a new 11kV or33kV line, and connecting either at an existing substation or byconstructing a new substation.

The model takes two approaches to site identification. There are sev-eral hundred weir locations already listed by the model, and each ofthese is tested. Turbine size and hence power output are based onhead and flow, but adjusted to take into account environmental sen-sitivity of the area. The costs of each element of the equipment,installation, connection and management costs are then calculatedtaking into account site conditions. These costs equations wereempirically derived using data provided by Black & Veatch. Thepower output of the scheme is calculated, using one of four turbineefficiency curves depending on the head to flow ratio. This leads tothe calculation of the revenue and, by applying a discount rate tofuture revenues and costs, to the net present value.More importantly, Hydrobot identifies sites where there is no

existing infrastructure. Firstly areas are selected with a minimumslope reflecting that of operational hydro schemes, based on expe-rience and historical data. Hydrobot places a turbine at the lowerextreme of the slope, and simulates a 20m penstock. The full costand revenue calculations are conducted as for weir sites above, toproduce a valuation of that layout. Hydrobot then extends the pen-stock to 40m and repeats the exercise, typically with a lower flowbut a higher head. In this way the model simulates a range of pen-stocks up to 1.5km. If one or more profitable solutions haveemerged, Hydrobot moves the turbine 20m upstream and repeatsthe whole exercise. And this process will continue, meaning thatmany hundreds of layouts may be tested within one area. When nomore viable layouts can be found, all the solutions are compared to

SOFTWARE

Schemes intersecting selected tiles within NN62SW. If valid solutions werefound, red dots mark turbine sites and red lines show suggested penstockroute. Blue numbers denote specific turbines


SOFTWARE

select the ‘best’, based on preferences that reflect the investment pro-files of different client-groups.

Multiple intakes are simulated by attempting to join nearby trib-utaries into a scheme, re-evaluating the combination, and compar-ing to the sum of the parts. Other tricks involve removing existingschemes, and simulating off-grid schemes, though the latter was notused in the Scottish study.

But what about dams? Storage schemes have not been forgotten.For every suitable site, the surrounding terrain is examined to deter-mine whether it would be suitable for construction of a dam. Thisis based on the profile of valleys in Scotland where dams have beenconstructed for hydro projects, and depends on the slope and heightof the banks, the width of the valley floor, and the flow in the water-course. Where a site is deemed suitable, the additional head andgreater efficiency of the system are taken into account, as well as theadditional costs, and the site is re-evaluated. Again, it is comparedto run-of-river options at the same site to determine whether a damwould be preferable.

By modelling multiple intakes on run-of-river schemes, and withthe inclusion of storage schemes, Hydrobot identified over 1000potential small hydro schemes across Scotland of up to 5MW, witha handful of schemes larger than this.

WHO GETS WHAT?The approach that Hydrobot takes, as described above, models howan engineer might identify a micro or small hydro scheme. Thereforeit is appropriate for four principle audiences:

• The small landowner or farmer, who may have one site in mind.• The developer, who may want the top sites in their region.• The larger estate owner, who wants to know the potential on their

land and where to begin.• Governments and local authorities, who want to know the con-

tribution that hydro can make to their targets, and how to releasethe bottlenecks.

Previous clients include the Scottish Government, the ForestryCommission, and multiple small estate and farm owners, and we arein discussions with several local authorities as well as developers andutilities. For each of these users Hydrobot can help reduce the timeand finances required to identify sites with potential. For some it isequally important to see how the results change as market condi-tions fluctuate or grants become available. After the initial cus-tomisation to users’ needs, Hydrobot can be re-run with differentinput values at very little extra cost. This allows developers andlandowners to quantify risk in more detail, which is especially rele-vant in the current economic climate.

A further benefit to re-running the model is the change in ourother climate – the weather. As the flow regimes in river systems alter,becoming more extreme in their flood-drought cycles in the UK, theviability of many hydro schemes must be re-examined. Flow regimescan be adjusted for a whole country with Hydrobot, and the siteidentification process repeated. In this way, renewable energy policycan also be risk-reduced.

FUTURE DEVELOPMENTS

Automated hydro site identification has taken a leap forward withthe modelling of Scotland using Hydrobot in 2008. The resultingreport champions the potential for grid-connected small hydro tocontribute to national renewables targets. Hydrobot was developedto answer questions being asked in Scotland at this time, but whatother questions are being asked?

• What about the potential for off-grid schemes?• What about private networks and community schemes?• Can you model other countries? Across the whole world?• Can you model pumped storage?• What about combining wind and pumped storage?• Can you model the water treatment network?• Don’t forget large hydro!

As a consultant, my answer to all of the above questions is ‘yes, ofcourse’. And as the model becomes more sophisticated with eachfuture version, it is likely that Scotland’s total resource will be refined.There may be an increase in the total as gaps such as off-grid andlarge hydro are filled. We would hope that the total will start toreduce as more and more of the identified sites are developed. Wewould hope to be producing results for other countries too, so thatwe start to put a clear number on the global potential for hydro.

But which question is being asked most urgently? This willdetermine the direction that Hydrobot takes over the next 12months and beyond. I’m sorry, but I have to say it – Hydrobot willgo with the flow.

Nick Forrest is Managing Director of Nick ForrestAssociates Ltd and Hydrobot Ltd. He is also a director ofbabyHydro Ltd, a new full services company establishedto develop small scale hydro schemes in Scotland from

feasibility to operation

The Hydrobot online service is available athttp://www.nickforrestassoc.co.uk.

For further information please [email protected]

IWP& DC

Map of Scotland with dots indicating 36,252 sites analysed by Hydrobot, ofwhich 1019 were found to be financially viable for commercial developmentas of August 2008

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All Services for Complete Solutions• from concept to completion and operation• from projects to complex systems• from local to multinational schemes• for public and private developers

Norconsult ASVestfjordgaten 4, 1338 Sandvika, Norway

Tel: +47 67 57 10 00Fax: +47 67 54 45 [email protected]

Power and Water ManagementNorconsult provides multidisciplinary consultancy services within power and water resources development.

www.norconsult.com

• River Basin Studies • Underground Hydropower • Dam Design• Turbine Maintenance and Optimisation • Transmission and Distribution • Environmental Impact Assessments • Financial Engineering • Power Utility Services

# (47) 67 53 15 06 in Norway# (55) 11 3722 0889 in BrazilE-mail: [email protected]: http//www.qtbm.com

35 years experience from more than 30 countries

AF-Colenco LtdTäfernstrasse 26 • CH-5405 Baden/SwitzerlandPhone +41 (0)56 483 12 12 • Fax +41 (0)56 483 17 [email protected] • http://www.af-colenco.com

Consulting / Engineering and EPC Services for:• Hydropower Plants• Dams and Reservoirs• Hydraulic Structures• Hydraulic Streel Structures• Geotechnics and Foundations• Electrical / Mechanical Equipment

formerly Electrowatt-Ekono and Verbundplan

Hydropower and Water Management with Worldwide

Experience and Local Presence Pöyry Energy Ltd., Hardturmstrasse 161, P.O. Box, CH-8037 Zurich, SwitzerlandTel +41 44 355 55 54, Fax +41 355 55 56, www.poyry.com Pöyry Energy GmbH, Laar-Berg-Strasse 43, A-1100 Vienna, Austria Tel +43 50 313 22 586, Fax +43 50 31 31 65, www.poyry.com

PROFESSIONAL DIRECTORY


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Yolsu Engineering Services Ltd. Co.Hürriyet Caddesi No:135 Dikmen, 06450 Ankara,TURKEYTel: +90 312 480 06 01 (pbx) Fax: +90 312 483 31 35

www.yolsu.com.tr [email protected]

Prefeasibilty, Feasibility,Final & Detail Design,Consulting Services:

• Basin development• Dams and hydropower plants• Irrigation and drainage• Water supply and sewerage• River engineering• Highways and railways

Construction Technique for Dams and Water PassagewaysSpilways - Piers, Walls and Chute Slab;

Power Houses - Pillars, Walls and Outlets;Water Intakes - Pillars, Shafts.

Contact:[email protected]: +55 11. 5181. 2527

......SSUUPPPPOORRTTIINNGG AANNDD

CCOOOOPPEERRAATTIINNGG IINN

CCOONNSSTTRRUUCCTTIIOONN......

Stellba Hydro AG Stellba Hydro GmbH & Co KGLanggas 2 Badenbergstrasse 30CH-5244 Birrhard D-89520 HeidenheimSwitzerland GermanyTelefon +41 (0)56 201 45 20 Telefon +49 (0)7321 96 92 0Telefax +41 (0)56 201 45 21 Telefax +49 (0)7321 6 20 73Internet www.stellba-hydro.ch Internet www.stellba.deE-Mail [email protected] E-Mail [email protected]

USE WWW.WATERPOWERMAGAZINE.COM TO DRIVE CUSTOMERS TO YOUR SITE

Have you seenour website?

Active links

File hosting

Contact

Content

Multi-layered “microsite” at waterpowermagazine.com12 months on-line advertising for the price of a

single full page ad!! £2500

COMPANY PROFILE

In the last six months, an average of 32,527 unique users did!!With an average of 32,527 unique users visiting www.waterpowermagazine.com and 287,846 page impressions displayed overthe last 6 months, NOW is the time to make the most of this superb opportunity to showcase your company to the world-wide

hydro industry in the most dynamic and cost effective way possible.

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CYLINDERS

RexrothBosch Group

Bosch Rexroth B.V.Cylinders

Application based standard cylinder designs for;radial gates, roller and slide gates, butterfly andball valves, turbine regulation, navigational locks

and movable bridges.

Bosch Rexroth B.V.Contact: Mr Bob Lamers, Tel: +31 411 651 778

www.boschrexroth.comMail to: [email protected]

CRANES

GATES

FILTRATION EQUIPMENT GROUTING

ARSA Int Construction Co. (pjs)

Head Office: No. 12 Shohada StMirzaye Shirazi AveTEHRAN 1586756513, I.R. IRANTel: +98 21 88717220 Fax: +98 21 88721847Email: [email protected] Website: www.arsa.ir

HEAT EXCHANGERS

Enerfin Inc.5125 J.A. Bombardier, St-Hubert

(Quebec) Canada, J3Z 1G4 Tel: + 1 450 443-3366

Fax: +1 450 443-0711 Email: [email protected]

Website: www.enerfin-inc.com

HIGH QUALITY COOLERS FOR:• Hydro Generators• Thrust Bearings• Transformers• Synchronous Condensers• Turbo Generators• Air Preheaters, etc.

Custom Design To Suit Your ApplicationExtruded Fins

Dam & HydropowerDrilling & GroutingPiling & Cast In Place PilesCutoff Diagram WallTunnelingHeavy Concrete Construction

Providing water control solutions through thoughtful engineering,innovative design, attention to detail and outstanding customerservice. Contact us for inflatable water control gates and rubberdams.

PO Box 668, Fort Collins, CO 80522 USATel: 970-568-9844www.obermeyerhydro.com

• Custom Design Hydraulic Cylinders• Servomotors• Piston Accumulators'• Hydraulic Power Units• Control Panels

www.doucehydro.comDouce Hydro FRANCE, USA and GERMANY

Tel France: + 33 / 3 22 74 31 08 ; E-mail: [email protected] USA: + 1 / 586 566 4725 ; E-mail: [email protected]

Tel Germany: + 49 / 177 398 37 78 ; E-mail : [email protected]

BEARINGS

PAN® bronzes and

PAN®-GF self-lubricating bearings

Since 1931

- Superior quality with • Highest wear resistance • Low maintenance

• Or maintenance free - Extended operating life

PAN-Metallgesellschaft

P.O. Box 102436 • D-68024 Mannheim / Germany Phone: + 49 621 42 303-0 • Fax: + 49 621 42 303-33 [email protected] • www.pan-metall.com

BEARING OIL COOLERS

HEXECO, Inc. ... a Heat Exchanger Engineering Co.Tel: +1 (920) 361-3440 • Fax: +1 (920) 361-4554E-Mail: [email protected] • Web: www.hexeco.com

OIL COOLERSFor

THRUST andGUIDE

BEARINGS

CONCRETE COOLING• COLD & ICE WATERPLANTS• FLAKE ICE PLANTS• ICE DELIVERY & WEIGHING SYSTEMS• ICE STORAGES

KTI-Plersch Kältetechnik GmbHCarl-Otto-Weg 14/2

88481 BalzheimGermany

Tel:/Phone: +49 - 7347 - 95 72 - 0Fax: +49 - 7347 - 95 72 - 22Email: [email protected]

Website: www.kti-plersch.com

CONCRETE COOLING

Telephone +44 (0)20 8269 7854

I N T E R N A T I O N A L

&DAMCONSTRUCTIONWaterPower

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HYDRO CASTINGS

HYDROMECHANICALEQUIPMENT

• Water turbine components• Castings from 100 kg to 30 tons• Latest CAD-CAM capabilities• Certified Quality Assurance ISO 9001• Environmental Management System ISO14001Your contact: Mr. Timo Norvasto, Sales ManagerLokomo Steel FoundryTel: +358 204 84 4222Fax: +358 204 84 4233Email: [email protected]: www.metsofoundries.com

DSD NOELL GmbHHYDROMECHANICAL EQUIPMENTEngineering, design, fabrication andinstallation of hydraulic steel structuressuch as gates, penstocks, stoplogs,trashracks including appurtenant drivesand electrical control systems as well asthe rehabilitation of existing plants.Alfred-Nobel-Straße 20,97080Würzburg, GermanyPhone (+49) 931 903-1215Fax (+49) 931 903-1009Internet: www.dsd-noell.come-mail: [email protected]

HYDRO POWERPLANT EQUIPMENT

! World wide referenced water to wire General Contractor! Turbines and Generators! Electromechanical Equipment! Switchgears! Control Protection Monitoring and SCADA Systems! Balance of the Plant! Turn key projects! Rehabilitation

S.T.E. S.p.a. - Via Sorio, 120 - 35141, PADOVA(Italy)tel. +39 049 2963900 - fax. +39 049 2963901

Email: [email protected] Web: www.ste-energy.comISO 9001 CERTIFIED

ANDRITZ HYDRO GmbHPenzinger Strasse 76, A-1141 Vienna, AustriaPhone: +43.1.89100-2659, Fax: [email protected] • www.andritz-hydro.com

Your partner for renewable energy.Hydro Power.

We focus on the best solution – from water to wire.

Voith Siemens Hydro Power Generation GmbH & Co. KGAlexanderstraße 1189522 Heidenheim/GermanyBarbara Fischer-AupperleTel. +49-7321-37 68 48 Fax +49-7321-37 78 28www.voithsiemens.com

! Water power plant equipment (electrical and mechanical)

! Pumps! Governors! Automation! Modernization of existing power plants! Management services

Contact:

INSTRUMENTATION(DAM MONITORING)

Geokon, Incorporated manufactures a full range of geotechnical instrumentation suitable for monitoring dams. Geokon instrumentation employs vibrating wire technology that provides measurable advantages and proven long-term stability.

The World Leader inVibrating Wire Technology TM

Geokon, Incorporated48 Spencer StreetLebanon, New Hampshire03766 • USA

Dam Monitoring Instrumentation

1 • 603 • 448 • 15621 • 603 • 448 • [email protected]

Alstom Hydro offers a complete range of equipment and services forboth new and existing hydro power plants, including:

• Turbines & generators for all sizes• Pump turbines, fixed/variable speed generators motors• Control & protection systems• Refurbishment and upgrade• Services• Small hydro• Hydro-mechanical and lifting equipment

4 Avenue André Malraux,92309 Levallois-Perret Cedex,France.T: +33 1 41 49 20 00F: + 33 1 41 49 37 52E: [email protected]: www.hydro.power.alstom.com

Alstom Hydro:

Vikas Kothari: Executive Director Tel: 91 11 29565552 TO 55Om Metals Infraprojects Ltd. Fax: 91 11 295655514th Floor, NBCC Plaza, Mobile: 91 98110 68101Tower III, Sector 5, Email: [email protected] Vihar, [email protected], New Delhi, 110 017, INDIA Web: www.ommetals.com

Turnkey EPC contracts for:•Radial Gates •Trash Racks & TRCM

•Vertical Gates •Gantry Cranes & EOT

•Penstocks •Mechanical/ Hydraulic Hoists

•Stoplogs •Draft Tubes

Turnkey EPC contracts for:•Radial Gates •Trash Racks & TRCM

•Vertical Gates •Gantry Cranes & EOT

•Penstocks •Mechanical/ Hydraulic Hoists

•Stoplogs •Draft Tubes

Om Metals

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STEEL CASTINGSMALL HYDROELECTRIC

POWER SETS

MICRO/SMALLHYDROELECTRIC POWER SETS

- HYDRO TURBINES PELTON PFRANCIS FKAPLAN

UP TO 10 MW

- CONTROL TECHNOLOGY w

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Global Hydro Energy GmbH 4085 Niederranna 41, Austria, [email protected]

INSTRUMENTATION(PROCESS CONTROL)

PROCESS CONTROL SYSTEMS• Measuring and control systems for water

treatment and energy management• Equipment, components and complete

systems on a turnkey basis for the segments of:- the water, gas, and electricity supply sectors- the waste disposals sectors (water treatment

and sewage)- hydroelectric power stations- hydrography

• Consulting, design, and project engineering,installation, training, and service

Rittmeyer Ltd.PO Box 464, 6341 BaarSwitzerlandPhone: +41 41 767 10 00Fax: +41 41 767 10 [email protected]

Partial Discharge?www.pdix.com

PARTIAL DISCHARGE DETECTION

INSTRUMENTATION(GEOTECHNICAL)

WORLD MARKETPLACE


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TRASHRACK RAKES

VALVES FOR HYDROELECTRIC POWER PLANTS! Butterfly Valves! Spherical Valves! Cone Jet Valves! Needle Valves! Spleeve Valves! Pressure Reducing Valves! Airation Valves

Adams Schweiz AGAustrasse 49, CH 8045 Zürich, SwitzerlandPhone: +41 (0) 44 461 54 15Fax: +41 (0) 44 461 50 20e-mail: [email protected]: www.adamsarmaturen.ch

VALVES

!"# $% &'# ($)*+,-*#.+/"0 1."2%.3&2)#)-$% '/0'452.*/&6 7.*7#-%$) +.1- ."+'6+)$8$(#)9 #7#" /"

(((:7.040)$28:3$1!!"!!"

WATER TURBINES

WATERPROOFING

WATERPROOFING AND PROTECTIONof concrete and RCC dams,

embankment dams, hydraulic tunnels,canals, reservoirs

WITH FLEXIBLE SYNTHETIC MEMBRANESTurnkey projects: design manufacturing,

supply, installation.

CARPI TECH S.A.Corso San Gottardo 86

CH 6830 Chiasso - SwitzerlandTel: +41 91 695 4000 Fax: +41 91 695 4009

Email: [email protected] Web: www.carpitech.com

CKD BlanskoHolding, a.s.Gellhornova 1,678 18 BlanskoCzech Republictel.: +420 516 401 111 fax: +420 516 413 [email protected] www.ckdblansko.cz

ReliableHydro Power

Hydraulic TurbinesFrancis, Kaplan, Pelton, Deriaz, Large and Small Hydro

Hydro-Mechanical EquipmentValves, Gates and Others

Turnkey ProjectsNew Instalations, Upgrading, Refurbishment

Own HydraulicLaboratory

HydroTurbines Specialists for……refurbishment of pel-ton and francis turbines

Partner for… …revision of hydraulic machines and valves

Practitioners with……9 hydro power plants – we speak hydro

Grimsel Hydro3862 InnertkirchenSwitzerland+41 33 982 27 00www.grimselhydro.ch

Stronger together.

TUNNELING

CIFA S.p.A. Via Stati Uniti d’America, 26>> 20030 Senago (MI) >> Tel. +39 02 990 131

>> Fax +39 02 998 1157 >> www.cifa.com

Member of the Group of companiesGlenfield Valves Ltd your specialist manufacturer of Discharge,Control and Isolating Valves for:• Dams and Reservoirs• Water Transmission Pipelines• Power Stations.

For a world wide network ofmanufacturing and serviceorganisations offering localsupport please contact:Glenfield Works, Queens Drive,Kilmarnock, Ayrshire,KA1 3XF, UKT: +44 1563 521150F: +44 1563 541013E: [email protected]: www.glenfield.co.uk

Hydro Power.We generate added value for you.

Service & Rehab provides solutions,products and services over the entirelife cycle of hydro power plants:• Plant Assessment • General Overhaul• Rehabilitation • Upgrading and Mod-ernization • Integrated Plant Control“NEPTUN” • Feasibility Studies • Resi-

ANDRITZ HYDRO GmbHPenzinger Strasse 76, A-1141 Vienna, AustriaPhone: +43.1.89100-2659, Fax: +43.1.8946046

[email protected]

dual Life Analysis • Risk Assessment• Training Services. The combination ofour global competence with our localpresence guarantees competent andon-the-spot response.

Service & Rehab – Your partner nearby.

1 enero 2009

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