etlands management echnical note g.3 ater resources and...

Environment DepartmentThe World Bank1818 H Street, N.W.Washington, D.C. 20433, U.S.A.www.worldbank.orgFor information on these publications contact theESSD Advisory Service at [email protected] call 202.522.3773

The World Bank Water Resources and EnvironmentTechnical Note G.3

Wetlands Management

Water Resources and EnvironmentTechnical Note G.3

Wetlands Management

Series EditorsRichard Davis

Rafik Hirji

Series EditorsRichard Davis

Rafik Hirji

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The World BankWashington, D.C.

WATER RESOURCES

AND ENVIRONMENTTECHNICAL NOTE G.3

Wetlands Management

SERIES EDITORS

RICHARD DAVIS, RAFIK HIRJI

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A. Environmental Issues and LessonsNote A.1 Environmental Aspects of Water Resources ManagementNote A.2 Water Resources Management Policy Implementation: Early Lessons

B. Institutional and Regulatory IssuesNote B.1 Strategic Environmental Assessment: A Watershed ApproachNote B.2 Water Resources Management: Regulatory DimensionsNote B.3 Regulations for Private Sector Utilities

C. Environmental Flow AssessmentNote C.1 Environmental Flows: Concepts and MethodsNote C.2 Environmental Flows: Case StudiesNote C.3 Environmental Flows: Flood FlowsNote C.4 Environmental Flows: Social Issues

D. Water Quality ManagementNote D.1 Water Quality: Assessment and ProtectionNote D.2 Water Quality: Wastewater TreatmentNote D.3 Water Quality: Nonpoint-Source Pollution

E. Irrigation and DrainageNote E.1 Irrigation and Drainage: DevelopmentNote E.2 Irrigation and Drainage: Rehabilitation

F. Water Conservation and Demand ManagementNote F.1 Water Conservation: Urban UtilitiesNote F.2 Water Conservation: IrrigationNote F.3 Wastewater Reuse

G. Waterbody ManagementNote G.1 Groundwater ManagementNote G.2 Lake ManagementNote G.3 Wetlands ManagementNote G.4 Management of Aquatic Plants

H. Selected topicsNote H.1 Interbasin TransfersNote H.2 DesalinationNote H.3 Climate Variability and Climate Change

Water Resources and Environment Technical Notes

Copyright © 2003

The International Bank for Reconstruction and Development/THE WORLD BANK

1818 H Street, N.W., Washington, D.C. 20433, U.S.A.

All rights reserved.

Manufactured in the United States of America

First printing March 2003

3

AuthorJoop de Schutter

Technical AdviserStephen Lintner

EditorRobert Livernash

Production StaffCover Design: Cathe Fadel

Design and Production:The Word Express, Inc.

NotesUnless otherwise stated,all dollars = U.S. dollars.All tons are metric tons.

Cover photo byWorld Bank

Wetlands in sand dunes,Namibia

This series also is available on theWorld Bank website

(www.worldbank.org).

CONTENTSForeword 5

Acknowledgments 7

Introduction 9

Types of Wetlands 11Wetlands include such freshwater ecosystems as flood-plains, marshes, peatlands, swamp forests, and coastalecosystems such as mangroves, estuaries, and opencoasts. They are distinguished by the presence of water;usually have unique soil conditions that differ from theadjacent areas; and support vegetation adapted toa dynamic hydrologic regime.

Threats to Wetlands 11Half of the world’s wetlands have disappeared since1900. Drainage for increased agriculture productionis the principal cause. Other wetlands have been de-graded by pollution, invasive species, and alterationsto flows. Many of these impacts originate from theupstream watershed.

Functions and Benefits of Wetlands 14Wetlands are some of the most productive ecosystemson earth. They regulate water flows; control sedimentand nutrient pollution; provide natural food and fiberfor dependent communities; offer productive areasfor agriculture and fishing; provide habitat for migra-tory birds and fish breeding; and support consider-able biodiversity.

Incorporating Wetlands Managementinto Bank Projects 18

Effective protection and restoration of wetlands requiresinvolving the various stakeholders; assessing a rangeof development options; attempting to place a valueon the services provided by wetlands; and institutinga monitoring and assessment program.

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WATER RESOURCES AND ENVIRONMENT • TECHNICAL NOTE G.3

Constructed Wetlands 25Wetlands can be constructed to provide specific ecosystem functions, particu5larly5treating and recycling wastewater. Constructed wetlands offer considerablesavings in wastewater treatment costs for small communities, as well as providingvaluable habitat and areas for public education and recreation.

Conclusion 26Wetlands provide a wide range of ecological functions that support the liveli-hoods of local communities as well as provide regional and global benefits.There is an increasing appreciation of the value of wetlands. Many agencies,including the World Bank, are attempting to preserve and restore wetlands.

Further Information 27

Boxes1. Lake Naivasha: A case of natural pollution control 162. Ecotourism in the Ukraine Danube Delta Biodiversity Project 173. The Mahanadi Delta, Orissa, India 184. The Kihansi Hydro Project and the Spray Toad 205. The Pantanal 216. Wetland mitigation banking: An innovative approach 227. Restoring the deltaic wetlands of the Northern Aral Sea 238. Valuing ecosystem services: the Hadejia-Nguru Wetlands 239. Integrated coastal zone management indicators in the Baltic Sea region 24

Tables1. Main wetland types 122. Main causes of wetlands loss 133. Functions of wetlands ecosystems 154. Driving Force Indicator Matrix 255. S-R Indicator Matrix 25

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FOREWORD

The environmentally sustainable development andmanagement of water resources is a critical andcomplex issue for both rich and poor countries. Itis technically challenging and often entails difficulttrade-offs among social, economic, and politicalconsiderations. Typically, the environment is treatedas a marginal issue when it is actually key to sus-tainable water management.

According to the World Bank’s recently approvedWater Resources Sector Strategy, “the environmentis a special ‘water-using sector’ in that most envi-ronmental concerns are a central part of overallwater resources management, and not just a partof a distinct water-using sector” (World Bank 2003:28). Being integral to overall water resources man-agement, the environment is “voiceless” when otherwater using sectors have distinct voices. As a con-sequence, representatives of these other water us-ing sectors need to be fully aware of the importanceof environmental aspects of water resources man-agement for the development of their sectoral in-terests.

For us in the World Bank, water resources man-agement—including the development of surface andgroundwater resources for urban, rural, agriculture,energy, mining, and industrial uses, as well as theprotection of surface and groundwater sources,pollution control, watershed management, controlof water weeds, and restoration of degraded eco-systems such as lakes and wetlands—is an impor-tant element of our lending, supporting one of theessential building blocks for sustaining livelihoodsand for social and economic development in gen-eral. Prior to 1993, environmental considerationsof such investments were addressed reactively andprimarily through the Bank’s safeguard policies. The1993 Water Resources Management Policy Paperbroadened the development focus to include theprotection and management of water resources inan environmentally sustainable, socially acceptable,and economically efficient manner as an emerging

priority in Bank lending. Many lessons have beenlearned, and these have contributed to changingattitudes and practices in World Bank operations.

Water resources management is also a critical de-velopment issue because of its many links to pov-erty reduction, including health, agriculturalproductivity, industrial and energy development,and sustainable growth in downstream communi-ties. But strategies to reduce poverty should not leadto further degradation of water resources␣ or eco-logical services. Finding a balance between theseobjectives is an important aspect of the Bank’s in-terest in sustainable development. The 2001 Envi-ronment Strategy underscores the linkages amongwater resources management, environmentalsustainability, and poverty, and shows how the 2003Water Resources Sector Strategy’s call for usingwater as a vehicle for increasing growth and re-ducing poverty can be carried out in a socially andenvironmentally responsible manner.

Over the past few decades, many nations have beensubjected to the ravages of either droughts or floods.Unsustainable land and water use practices havecontributed to the degradation of the water resourcesbase and are undermining the primary investmentsin water supply, energy and irrigation infrastruc-ture, often also contributing to loss of biodiversity.In response, new policy and institutional reformsare being developed to ensure responsible and sus-tainable practices are put in place, and new predic-tive and forecasting techniques are being developedthat can help to reduce the impacts and managethe consequences of such events. The Environmentand Water Resources Sector Strategies make it clearthat water must be treated as a resource that spansmultiple uses in a river basin, particularly to main-tain sufficient flows of sufficient quality at the ap-propriate times to offset upstream abstraction andpollution and sustain the downstream social, eco-logical, and hydrological functions of watershedsand wetlands.

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With the support of the Government of the Nether-lands, the Environment Department has preparedan initial series of Water Resources and Environ-ment Technical Notes to improve the knowledgebase about applying environmental managementprinciples to water resources management. TheTechnical Note series supports the implementationof the World Bank 1993 Water Resources Manage-ment Policy, 2001 Environment Strategy, and 2003Water Resources Sector Strategy, as well as theimplementation of the Bank’s safeguard policies.The Notes are also consistent with the MillenniumDevelopment Goal objectives related to environmen-tal sustainability of water resources.The Notes are intended for use by those withoutspecific training in water resources managementsuch as technical specialists, policymakers andmanagers working on water sector related invest-ments within the Bank; practitioners from bilateral,multilateral, and nongovernmental organizations;and public and private sector specialists interestedin environmentally sustainable water resourcesmanagement. These people may have been trainedas environmental, municipal, water resources, ir-rigation, power, or mining engineers; or as econo-mists, lawyers, sociologists, natural resourcesspecialists, urban planners, environmental planners,or ecologists.

The Notes are in eight categories: environmentalissues and lessons; institutional and regulatory is-sues; environmental flow assessment; water qual-ity management; irrigation and drainage; waterconservation (demand management); waterbodymanagement; and selected topics. The series maybe expanded in the future to include other relevantcategories or topics. Not all topics will be of inter-est to all specialists. Some will find the review ofpast environmental practices in the water sectoruseful for learning and improving their perfor-mance; others may find their suggestions for fur-ther, more detailed information to be valuable; whilestill others will find them useful as a reference onemerging topics such as environmental flow assess-ment, environmental regulations for private waterutilities, inter-basin water transfers and climatevariability and climate change. The latter topics arelikely to be of increasing importance as the WorldBank implements its environment and water re-sources sector strategies and supports the next gen-eration of water resources and environmental policyand institutional reforms.

Kristalina GeorgievaDirector

Environment Department

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WETLANDS MANAGEMENT

ACKNOWLEDGMENTS

The production of this Technical Note has beensupported by a trust fund from the Government ofthe Netherlands managed by the World Bank Envi-ronment Department.

This Note was drafted by Joop de Schutter of Re-source Analysis, the Netherlands. The Note wasreviewed by Hans-Olav Ibrekk and Kathleen

Mackinnon of the World Bank. Maria Isabel Bragaand Colin Rees of the World Bank provided helpfulcomments on the structure of the Note. HenrikDissing of the WWF and Gayatri Acharya of theWorld Bank provided information on the Baltic SeaEnvironment Program and the Hadejia-Nguru wet-lands in Nigeria, respectively.

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WETLANDS MANAGEMENT

there are no feasible alternatives for the project andits siting, and comprehensive analysis demonstratesthat overall benefits from the project substantiallyoutweigh the environmental costs. These habitatsinclude freshwater lakes and rivers, coastal marshes,wetlands, and estuaries. The 1993 Water ResourcesManagement Policy notes the need to “protect en-vironmental resources in floodplains and wetlands,”and the recent Water Resources Sector Strategy rec-ognizes that wetlands provide valuable environmen-tal services to dependent communities. An Updateto the Environmental Assessment Sourcebook2 pro-vides advice on assessing wetland ecosystems. TheBank has supported regional wetland assessments—such as the 2000 map of Wetlands in Asia and theproduction of a booklet with Wetlands Interna-tional—and has invested in projects that includewetland protection and restoration in most parts ofthe developing world. This Note provides technicalsupport to the integration of wetlands managementprinciples into water resources planning and de-velopment, as well as strategic instruments suchas country environmental analysis.

In the next section, we describe the different typesof wetlands and their occurrence in various bio-geographic regions. We then describe the rapid loss

of these wetlands aroundthe world and the causesof this loss. Althoughsome of this loss can beattributed to naturalevents, most of it arisesfrom human activitiessuch as land use conver-sion and diversion ofriver flows for agricul-tural development. The

Many wetlands around the world are being lost orare under threat. In many cases, losses are causedby direct development activities such as irrigationsystems, conversion to agricultural land, reclama-tion for urban expansion, or aquaculture such asprawn culture in mangrove systems in South andSoutheast Asia. In other cases, it is the result of off-site developments such as excessive upstream wa-ter use, exemplified by the loss of the Amu Daryaand Syr Darya river delta ecosystems in the AralSea Basin; water pollution, such as the influence ofthe Aswan Dam on sediment deposition in the NileDelta; or the introduction of invasive species. Wa-ter withdrawals are projected to increase by 18 per-cent in developed countries and by 50 percent indeveloping countries over the next 25 years, so thesethreats to wetlands are likely to worsen and havesignificant impacts on the natural environment andhuman welfare.

Existing wetlands, such as floodplains and river es-tuaries, are often highly productive and play a veryimportant role in both ecological functioning andhuman subsistence.1 The loss of wetlands is pos-ing a significant threat to aquatic biodiversity; morethan 800 species of plants and animals currentlythreatened with extinction are found in freshwaterecosystems.

The World Bank recog-nizes the importance ofwetlands in its policies aswell as in its operations.OP 4.04 (Natural Habi-tats) states that the Bankwill not support the sig-nificant conversion ofnatural habitats unless

INTRODUCTION

1 World Bank (2002) states that the productivity of estu-aries is around 50 times that of grasslands and 8 timesthat of wheat fields.

2 World Bank (2002).

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beneficial functions provided by wetlands are ex-plained in the following section. The final sectionprovides details of environmental protection (toavoid loss), planning, and management of wetlands.These include adherence to Bank safeguard poli-cies, full stakeholder participation, the importance

of assessing the value of services provided by wet-lands, the costs of retaining wetlands in develop-ments (including mitigation measures), and theselection of indicators and a monitoring program toimplement them.

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WETLANDS MANAGEMENT

TYPES OF WETLANDS

The “Ramsar Convention3” has defined wetlands as:

areas of marsh, fen, peatland, or water, whethernatural or artificial, permanent or temporary, withwater that is static or flowing, fresh, brackish orsalt, including areas of marine water the depth ofwhich at low tide does not exceed 6 meters.

According to the Ramsar Convention and scientificliterature, wetlands can be classified into three maintypes:n Inland wetlands, including permanent and sea-

sonal rivers, inland deltas and floodplains, per-manent and seasonal lakes and ponds, marshes,freshwater swamp forests, and peatlands.

n Marine/coastal wetlands, including open coast,coral reefs, estuaries, tidal flats, mangrove for-ests, and coastal lagoons. These wetlands oc-cupy about 8.6 million km2, or 6.4 percent ofthe world’s land surface (OECD, 1996). About56 percent of these wetlands are located in thetropics and subtropics.

n Artificial or human-made wetlands, includingreservoirs, aquaculture ponds, excavations andborrow pits, wastewater treatment ponds andirrigation canals, ditches, and rice fields.

The first two types can occur in a range of land-scape settings, as shown in Table 1. The third type,artificial or constructed wetlands, will be discussedat the end of this document. Although the Ramsardefinition allows for coral reefs and off-shore ar-eas, we exclude them here and deal only with fresh-water and coastal wetlands including tidal areas,estuaries, and mangrove areas.

Wetlands are always distinguished by the presenceof water, either at the surface or within the root zoneand usually have unique soil conditions that differfrom adjacent areas. Wetlands support vegetation(hydrophytes) adapted to a dynamic hydrologic re-gime; consequently this vegetation tends to be flood-tolerant.

3 The 1971 Ramsar Convention on Wetlands of Interna-tional Importance was established as the first global, in-tergovernmental conservation treaty for wetlands.4 Roggeri, H. (1995).

THREATS TO WETLANDS

There are few exact figures available on the extentof wetlands loss worldwide, although experts esti-mate that half of the world’s wetlands have disap-peared since 1900. Drainage for increasedagriculture production is the principal cause (Table2). It is estimated that in 1985 alone, drainage ofwetlands for intensive agriculture caused between55 and 65 percent of wetlands loss in Europe andNorth America and 30 percent in Asia, SouthAmerica, and Africa. In the latter regions, the im-pact of agricultural drainage on wetlands is increas-ing rapidly as growing populations demand morespace for food production.

Even protected wetlands are threatened or deterio-rating. Disturbances were recorded in some 75 per-cent of the almost 957 sites designated as wetlandsof international importance (Ramsar Sites) in 1998.

Agricultural impacts, water flow regulation, pollu-tion, and habitat destruction or deterioration werethe predominant causes of degradation and dete-rioration of these sites.

Loss and degradation of wetlands from drainage,alterations to flow regimes, decreases in water qual-ity (see Notes D.1-3) and invasion by alien species(see Note G.4) often have far-reaching ecologicaland economic consequences. This is illustrated bythe following examples:4

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TABLE 1.MAIN WETLAND TYPES

Character Examples

Inland Wetland Floodplain Floodplains occur in alluvial lowlands adjacent The Niger delta in Mali extends over 2 million

to rivers with large variations in discharges and hectares during the wet season; during theseasonal or intermittent flooding. They are dry season, it covers only 400,000 hectares.common in tropical rivers with extensive inland Lake Chad is a shallow lake that includesand/or deltaic systems and often possess swamps and marshes. Other examples areshallow lakes and oxbows. Permanent shallow large parts of the Amazon, Lake Naivasha inlakes are characterized by submerged Kenya, Lake Tempe in Indonesia, and theaquatic plants or plants with floating leaves, Inner Delta of the Magdalena River inand seasonal variations in water levels. Colombia.

Marsh Marshes are normally dominated by emergent, The Sudd in Sudan is reputedly the world’srooted grassy vegetation (e.g. grass, reed) largest marsh. Other examples include thecharacterized by muddy, waterlogged soils. Okavango Delta in Botswana, most of LakeThey generally develop in areas where the Chad, and very large areas of the Amazonwater level tends to vary considerably. and Congo/Zaire River Basins.Marshes never fully dry out.

Peatland Peatlands develop when organic debris Peatlands are found in coastal tropicalproduced by swamp vegetation is not fully areas—the islands of Sumatra, Irian Jaya, anddecomposed as a result of waterlogging, Sulawesi in Indonesia, and Negril Morass inoxygen deficiency, high acidity, low Jamaica—and high-altitude areas such astemperatures, or nutrient deficiency. They the highlands of East Africa, Lesotho, andhave high average carbon content; Papua Niuginni.typically 50 percent.

Swamp Forest Swamp forests are mainly found along the Swamp forests are found in Southeast Asialowest shores of water bodies, in depressions (Indonesia, Papua Niuginni, Malaysia), Centralor on waterlogged soil. They develop where Africa (Zaire, Congo, Gabon, and the Nigershallow stagnant water occurs during a large Delta), the Amazon Basin, and Centralpart of the year. Swamp forests never fully America (Costa Rica).dry out.

Coastal Wetland Mangroves Mangroves are tidal forests consisting of plant Mangroves are found along the coasts of Asia;

formations typically developing on sheltered Indonesia accounts for almost one third of thecoastlines. They only occur in tropical and total. Other examples include the Sundarbanssubtropical regions. Mangrove tree species on the Bangladesh-Indian border, which isthrive in shallow, variable tidal environments. a well-preserved large-scale mangroveThey typically develop where fresh and marine ecosystem; the coasts of Brazil; and severalwaters meet; both influence local ecosystem Caribbean and West African countries.conditions.

Estuary Estuaries occur where river and marine Found in all countries with coastlines.ecosystems meet. They are characterized byvariations in water salinity levels and oftensaline stratification. Estuaries usually include alarge variety of wetland habitats, includingmangroves and coastal lagoons in tropicaland subtropical regions.

Open Coast Open coasts are not subject to the direct The Wadden Sea in Northern Europe is aninfluence of rivers and lagoon systems. example of a wetland on an open coast.They may include habitats such as tidalflats and mudflats and, in tropical/semi-tropical areas, mangroves.

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n Flood problems in Colombo, Sri Lanka, wors-ened after nearby swamps were filled in. Thedrainage of wetlands had a similar effect on sev-

eral towns in the lower Perak basin in Malaysia.n Drainage of peat swamps near Bushenyi in

Uganda led to serious water supply problems;

TABLE 2.MAIN CAUSES OF WETLANDS LOSS

Human ActionsDirectDrainage for agriculture, forestry, and mosquito controlDredging and stream channelization for navigation and flood protectionFilling for solid waste disposal, roads, and commercial, residential and industrial developmentConversion for aquaculture/maricultureConstruction of dykes, dams, levees, and seawalls for flood control, water supply, irrigation, and storm protectionDischarges of pesticides, herbicides, nutrients from domestic sewage and agricultural runoff, and sedimentMining of wetland soils for peat, coal, gravel, phosphate, and other materialsGroundwater abstraction

IndirectSediment diversion by dams, deep channels, and other structuresHydrological alterations by canals, roads, and other structuresSubsidence due to extraction of groundwater, oil, gas, and other minerals

Natural CausesSubsidenceSea-level riseDroughtHurricanes and other stormsErosionBiotic Effects

Absent or exceptional=Present, but not a major cause of loss=

Common and important cause of wetland degradation and loss=

Inland Wetlands

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Most wetlands provide multiple resources, prod-ucts, and services—depending on their biological,chemical, and physical characteristics and the in-teraction among these characteristics. Various meth-ods have been developed to describe the functions,values, and benefits of wetlands. The Function ValueAnalysis method5 assumes that the resources, ser-vices, and products provided by wetlands arise fromthe four basic functions listed in Table 3 and de-scribed below.

REGULATION FUNCTIONS

Regulation functions describe the capacity of eco-systems to regulate ecological processes that con-tribute to a healthy environment, such as localclimate stabilization, water flow regulation, andgroundwater recharge. These functions are char-acterized by not requiring any human interventionand are usually unnoticed until they are disturbed,such as increased flooding as a result of wetlanddrainage.

Wetlands provide crucial habitat to a wide range ofspecies, including mammals, reptiles, amphibians,fishes, insects, waterfowl, crustaceans, plants andmany other living organisms. Wetlands also pro-vide nursery and migration habitat for bird and fish

species. For example, the Kafue Flats in Zambiasupport a large population of the Kafue lechwe, awetland antelope unique to this particular flood-plain. The Niger inner delta hosts up to 1.5 millionbirds each year, which is 85 to 100 percent of waterbirds recorded in the Niger River Basin.

Maintenance of regional water balances is anotherimportant regulation function of wetlands. Reten-tion of water in floodplains will decrease down-stream flood damage by both reducing the heightof flood peaks and diminishing the volume of flood-waters through groundwater infiltration and evapo-ration. Flood control by wetlands is now beingrediscovered as a water management tool in manyparts of the world, including developed countriessuch as those along the Rhine River in Western Eu-rope. In arid regions, wetlands are a critical sourceof groundwater recharge (Note G.1). For example,each year the floodplains of the Hadejia River Ba-sin in northern Nigeria supply around 1.4 x109 m3

to and from the wetlands and has led to a largedecline in fisheries.

These environmental problems and associated costsoccurred because of a poor appreciation of wetlandecosystems and the services they provide. Althoughthere have been few attempts to place an economicvalue on the ecosystem services provided by wet-lands, it is clear that the costs from the loss of wet-lands can be substantial. For example, anassessment of floodplain productivity in Bangladeshconcluded that a different operational regime forwater flows in rivers and canals of the delta—in linewith fish migration patterns—could probably doublefish productivity.

the drained area is no longer able to store ex-cess water and release it evenly during the dryseason.

n Overgrazing and deliberate fires in the peat-forming swamps of Lesotho led to considerableerosion in the Orange and Tugela rivers.

n Flood levels downstream of the Bakalori Damin the Sokoto valley, Nigeria, dropped by 50percent, causing a 53 percent fall in thefloodplain’s cropped area. The loss of agricul-tural production from this modification of theflooding regime has been valued at $7 millionannually.

n Construction of the Markela Dam on the NigerRiver in Mali has blocked fish migration routes

5 Originally developed by de Groot, R.S. 1992. Functionsof Nature. Evaluation of Nature in Environmental Plan-ning, Management and Decision Making. The Netherlands:Wolters-Noordhoff. Further elaborated by Koudstaal, R.and R. Slootweg (1994).

FUNCTIONS AND BENEFITS OF WETLANDS

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TABLE 3.FUNCTIONS OF WETLANDS ECOSYSTEMS

Regulation n Flood attenuation and controln Prevention of saline water intrusionn Groundwater recharge and dischargen Protection against natural forces (e.g. climate influences)n Sediment retentionn Storage and recycling of organic matter and nutrientsn Storage and recycling of toxicantsn Regulation of biological control mechanismsn Maintenance of migration and nursery habitatsn Maintenance of other wetlandsn Maintenance of biological diversityn Storage of carbon dioxide

Carrier n Human habitation and settlementn Cultivation: crops, animal husbandry, aquaculturen Energy (solar and hydropower)n Recreation and tourismn Navigation

Production n Water as a harvestable resource (drinking)n Naturally produced food and raw materials (e.g. fish, wood, shellfish, salt, etc.)n Fodder and fertilizern Genetic resourcesn Medicinal resourcesn Biochemicals (oil, rubber, tannins, etc.)

Information n Aesthetic informationn Spiritual and religious informationn Historical informationn Cultural and artistic informationn Educational and scientific information

to the Chad aquifer. In some cases, wetlands sup-port dry-season flows through a delayed release offloodwaters. For instance, the swamps and lakes ofthe White Nile supply 83 percent of the water flow-ing into the lower course of the Nile during the dryseason.

The quality of surface and groundwater is also posi-tively influenced by wetlands. The vegetation andtopography of wetlands slows down water flows,allowing sediments to settle and nutrients to be re-moved by both plant uptake and attachment to sedi-ments (Box 1). Wetlands can often remove pollutantsmore cheaply than can engineering solutions. InSweden, for instance, the removal of nitrogen by a

restored wetland cost $0.67 / kg in 1991, comparedto $33/ kg for removal via a treatment plant. Wet-lands such as rice paddies and swamps release avariety of gases such as nitrogen and methane intothe atmosphere through microbially mediated pro-cesses and help maintain global cycling of carbonand other elements. Toxic materials, such as agri-cultural chemicals and some industrial wastes, arereadily adsorbed/absorbed onto sediments, and socan also be removed from rivers when the velocityof water flows diminishes in wetlands. However,these toxicants can then cause ecological damagewithin the wetlands, unless the wetlands are spe-cifically designed for pollutant removal (see sec-tion on Constructed Wetlands).

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Finally, as a result of their high humidity and evapo-transpiration rate, extensive wetlands can influencethe local and regional climate. They can have a cool-ing effect if located near highly developed areas,which might reduce impacts of “heat islands” aris-ing from the heat generated by large urban centers.

CARRIER FUNCTIONS

Carrier functions represent the provision by wet-lands of suitable space, substrate, or medium forhuman activities such as agriculture, aquaculture,animal husbandry, recreation, waterway navigation,tourist sites, and nature protection. Many of theseuses change the natural environment and may in-

fluence the functioning of wet-lands as a whole.

Agriculture that utilizes wet-lands is very important in manytropical wetlands where com-munities have developed tech-niques to benefit from naturalconditions, such as flood andflood-recession agriculture andswamp agriculture. Develop-ment programs often neglectexisting agricultural production,yet it not only supports the live-lihood of indigenous people, butit may also be efficient and sus-tainable. In the Senegal Riverfloodplain, the daily remunera-tion is $1.04-2.00 for flood-reces-

sion sorghum, compared to $0.67-1.04 for rice grownin irrigation schemes.

Livestock farmers often lead their herds towardwetlands during the dry season, when uplandgrasses and water reserves are exhausted. TheUtengule Swamp in the Usanga Plain of Tanzaniais an important source of dry-season water supplyfor over 300,000 head of livestock. The draw-downzone of Lake Chad provides excellent grazing ar-eas that may annually produce as much as 2 tonsof dry matter per hectare. In Brazil, Paraguay, andBolivia, the wetlands of the Pantanal support up to8 million head of cattle and are some of the mostvaluable in the world.

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BOX 1:LAKE NAIVASHA: A CASE OF NATURAL POLLUTION CONTROL

Lake Naivasha in southern Kenya has experienced a population explosion from 50,000 to 250,000 people within thelake’s catchment, a major expansion of intensive horticultural industries on the shores of the lake, and clearing andsettlement in the headwaters of the lake’s main river. The sewage treatment plant for the town of Naivasha has ceasedto operate; raw sewage has been discharged directly into the lake since 1993.

In spite of this pollution, water quality in the lake appears to have remained remarkably unaffected, although it mayhave reached the limits of its assimilative capacity. Nutrient concentrations have remained relatively unchanged;pesticides and heavy metals are detectable in trace amounts only; and sedimentation is not a major problem.The lake apparently has been protected by fringing reed beds, often 20m thick. These have filtered sediments andattached pollutants from riverine and drainage inflows, including the raw sewage. There are constant threats to thereed beds from burning and plans for development of the shoreline. Any major loss of these filters would almostcertainly see the lake become polluted, at significant cost to the local economy.

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The use of wetlands for tourism and recreation isgrowing rapidly. Often wetlands protection activi-ties are combined with ecotourism, which offers anopportunity for cost recovery for much of the in-vestments in nature protection activities (Box 2).The Black River swamps in Jamaica draw 50,000visitors per year, generate annual revenue of $1million, and provide jobs for 200 people. In anotherexample, the Okavango delta in Botswana and theKafue Flats in Zambia draw large numbers of tour-ists because of the spectacular range of game.

PRODUCTION FUNCTION

Production functions are goods produced naturallyin wetlands, as opposed to cultivated plants andanimals. Only time and energy are necessary in-vestments for their harvest. These goods includewater itself, naturally produced food (meat, fruit,fish), raw materials (peat and firewood), and ge-netic and medicinal resources. The natural food,water, and energy supply that many communitiesdepend upon for their existence is included in thiscategory. For example, local communities harvest115,000 tons of firewood per year from the Hadejia-Nguru floodplain in Nigeria. In the Sudd wetlandsin Sudan, hunting provides 25 percent of the meatconsumed by local people.

Fisheries are one of the most important activitiessupported by wetlands. Fish caught in wetlandsprovide an important source of protein for commu-nities around the world. For example:

n The 1987 catch from the seasonal lakes of theOgan-Komering floodplain in Sumatra was as-sessed at $15 million.

n In the Niger inner delta in Mali, some 100,000fishermen provide around 90 percent of nationalfish production.

n In the Kulna-Jessore drainage rehabilitationproject in southwest Bangladesh, fish produc-tion is more profitable than rice cultivation.

Wetlands, particularly coastal wetlands, also pro-vide a critical spawning area for fish, invertebratessuch as prawns, and other aquatic food. Box 3 de-scribes the attempt to reestablish the productivityof an important fish spawning area in India.

INFORMATION FUNCTIONS

Wetlands also provide opportunities for spiritualenrichment and recreation. Information functionsinclude aesthetic, spiritual and religious, historicaland archaeological elements, cultural and artistic,educational, and scientific activities. Although thevalue of these functions can be difficult to quantify,it can be large.

Wetlands have played a significant role in the de-velopment of many civilizations; their historical im-portance is enormous. In some areas, manygenerations have grown up near and within wet-lands, which are an important feature in their art,literature, and religions. The methods developed bythese communities to make sustainable use of wet-

BOX 2.ECOTOURISM IN THE UKRAINE DANUBE DELTA BIODIVERSITY PROJECT

The $1.5 million GEF-funded Danube Delta Biodiversity Project has supported the development of administrativefacilities for the reserve, with a small hotel, simple guest houses on the Delta islands, and development of a bird-watching trail. The project also sponsored staff visits at reserves in Europe to learn good practices in self-financing.Since the project was completed in 1999, the Ukraine Danube Biosphere Reserve (DBR) has been developing revenuesources and creating jobs through ecotourism. The DBR has created a special division for ecotourism and offerslodging, food, guides, and auto and boat transport. In order to avoid dependence on the quality of outside tourismfirms and to capture a greater share of tourism revenues, the DBR has obtained a license for conducting touristactivities itself. With the money earned thus far, they have built an observation tower and equipped their informationcenter.

Source: World Bank. 2002. ECA Biodiversity Strategy. Washington: World Bank.

18


land resources may have great learning potentialfor research and possible replication in other re-gions. For example, aquaculture and fishing tech-niques developed in the wetlands of Benin arestriking examples of ingenious traditional tech-niques with potential for use in other regions. InLake Titicaca, between Bolivia and Peru, the Uros

people have lived for centuries on floating islandsbuilt of totora reeds. They use boats made from thesame material for traveling between the islands.Fish, caught using artisanal methods, provide theiranimal protein. Even if these techniques are not rep-licable elsewhere, they contribute to human diver-sity and provide cultural benefits to humankind.

BOX 3.THE MAHANADI DELTA, ORISSA, INDIA

Over the centuries, the delta and extensive floodplains of the Mahanadi River in the Indian state of Orissa haveprovided rich fishery resources supported by tidal estuaries with seasonal freshwater and saltwater conditions. The deltawetlands also provided extensive spawning grounds for freshwater prawns and fish. In the later part of the 20th century,the conversion of the delta into irrigated land and changes in the hydrology of the river, particularly the construction ofthe Hirakud dam upstream of the delta in 1958, have caused many aquatic species to virtually disappear.

Indian carp species (Catla catla, Labeo rahita, L. calbasu and Cirrhina mrigala) live in the delta and are totallydependent on monsoon floods for spawning. The more intense the flood, the more fry will be produced. Due to theHirakud dam and the abstraction of water for irrigation, spawning is virtually absent during years of low rainfall whenfloods are controlled. Freshwater Macrobrachium prawns also reproduce in the brackish waters of the delta. Thehatched juveniles migrate upstream into freshwater areas during a 3-month post-monsoon period. Maintenance ofpost-monsoon discharge is essential for this activity.

The replacement of the deteriorating Naraj Weir by the Naraj Barrage, under the World Bank-funded Orissa WaterResources Consolidation Project, provided an opportunity to improve the fish and prawn breeding potential of thedelta. The new barrage will be provided with gates for flow regulation, which could make it possible to manage tosome extent the inflows into different branches of the delta. A fish pass—with a width of 2 meters—will be included. Theoperating rules for the barrage state that, once irrigation requirements are met, the first monsoon floods should be ashigh as possible to enhance spawning of carp, and that a continuous flow will be maintained through the barrageafter the monsoon to allow upstream migration of prawns. The operation of the barrage will be adjusted to maximizethese spawning activities as knowledge of flow-biology relationships grows, subject to the requirement that irrigationneeds are met.

Source: World Bank. 1998. Integrating Freshwater Biodiversity Conservation with Development: Some Emerging Lessons. EnvironmentDepartment Paper No. 61. Washington: The World Bank.

INCORPORATING WETLANDS MANAGEMENTINTO BANK PROJECTS

Projects that involve wetlands need to follow the samegeneral principles as projects involving other envi-ronmental resources: the extent of impact needs tobe assessed; the various stakeholders with an inter-est in the wetland need to be involved; options needto be developed involving different levels of mitiga-tion; the costs of wetlands losses need to be estimatedand compared to the benefits from the developmentunder the different options; mitigation measuresneed to be agreed and incorporated into the project;

and a monitoring program needs to be instituted totrack the success of the implementation

IMPACT ASSESSMENT

The need for wetlands management arises in dif-ferent types of Bank projects, including:n Projects that affect the hydrology of wetlands,

through such upstream activities as road con-struction, dam developments and irrigation

19

WETLANDS MANAGEMENT

schemes, lowering of water tables thoughgroundwater exploitation for water supply, andflood control investments.

n Direct conversion of noncritical wetlands toagriculture, ports and harbors, navigationprojects, and aquaculture, especially mangrovesfor mariculture. Under its Natural Habitat Policy,OP4.04, the Bank does not fund projects involv-ing significant conversion of critical wetlandhabitat areas unless there are no feasible alter-natives and the benefits substantially outweighthe costs.

n Projects that change the water quality and thebiological composition of wetlands throughpollution from agricultural runoff, urban andindustrial discharges, introduction of exoticplant and animal species, acid rain, and sea-level rise.

The Bank’s Operational Policy 4.01 applies to allBank-funded projects likely to have significant en-vironmental impacts on wetlands, including impactscaused by any of the above effects. Several other poli-cies can also be triggered by projects that affect wet-lands, including pest management (OP 4.09), waterresources management (OP 4.36), indigenous people(OP 4.20), and involuntary resettlement (OP 4.30).

When a particular project is likely to impact a wet-land, the following questions should be asked:n Is the area on the Ramsar list, the list of

biodiversity hotspots, or any national listing ofareas requiring protection?

n Will there be significant changes in the ecologi-cal structure and functioning of the wetland?

n Is the project likely to increase nutrients, pesti-cides, and other pollutants, or induce physicaldisturbance to the wetland?

n Will any part of the wetland be converted to adifferent land use?

n What is the present socioeconomic value of thewetland? What would be the sustainable yieldunder better management? What is the replace-ment cost if the ecosystem services currentlyprovided by the wetland are destroyed?

n Are local people willing and able to adapt theirtraditional practices to the likely changes inwetland functioning resulting from the project?

Borrowers are required to undertake an Environ-mental Assessment (EA) if the project receives anA or B environmental rating.6 Issues arising fromthe proposed development will be identified in theEA, and appropriate mitigation measures will beincluded in either the EA or a separate Environ-mental Management Plan (EMP). If a project is likelyto affect a wetland located off the site of the projectarea itself, an EA should take into account the ex-isting and future relationships between a wetlandand neighboring ecosystems. This may necessitateexpansion of the geographical coverage of the EAand generation of sufficient hydrological, ecologi-cal, and socioeconomic linkages to capture and re-spond to all significant potential social andenvironmental impacts (Box 4).

The EA should contain baseline data for assessingthe potentially positive and detrimental impacts ofthe proposed project. Because many wetlands func-tion seasonally, the data should describe the usesand services of the wetland over each season. TheEA should include assessments of the importanceand value of the wetland to affected local commu-nities and groups, such as women, fishing families,and livestock owners.

STAKEHOLDER PARTICIPATION

The Bank (and often national laws and procedures)requires involvement of stakeholders at an earlystage of major project proposals in most countries.Usually the Ministry of Environment—but also typi-cal development ministries such as Energy, Indus-try, Public Works, and local and regional water andenvironment management agencies—must be con-sulted regarding the application of these laws andprocedures.

Specific attention must be given to ensuring thatstakeholder groups, such as local communities de-pendent on the wetland functions and services, areincluded in the project planning at an early stage.Communities dependent on groundwater recharged

6 See World Bank 2002.

20


from seasonal wetland flooding are potentially justas affected by proposals that affect wetland hydrol-ogy as those living in the wetlands. Other groupssuch as NGOs, the general public, and business lead-ers may also be included if they have specific inter-ests in the wetland.

Failure to involve groups that are highly dependenton wetlands can impose large, subsequent socialcosts on the project and may even lead to the can-cellation of the project. The protests of ethnic groupsagainst the construction of a large-scale waterway(Hidrovia) in Brazil led to the licensing process forthis development being suspended. These groupshad not been involved, even though the Brazilianconstitution guarantees indigenous people the rightto be consulted regarding water projects that wouldaffect them (Box 5).

DEVELOPMENT OPTIONS

The choice of how much protection and how muchdevelopment is appropriate for a wetland or sys-tem of wetlands will depend on a range of factors,including alternative uses for the land and water(both upstream and downstream) of the wetland,and the ecological functions supplied by the wet-

land. It should be guided by well-established prin-ciples of ecological management:7

n Principle of Wise Use. As formulated by theRamsar Convention, wetlands should besustainably utilized “for the benefit of human-kind in a way compatible with the maintenanceof the natural properties of the ecosystem.”

n Principle of Interdependence. Wetlands cannotbe considered independently or as an isolatedecosystem. They should be managed on a widerecosystem basis, particularly the watershedwithin which they are located, which may crosspolitical and social barriers and different sec-tors. This includes groundwater systems feed-ing the wetlands.

n Principle of Multiple Use. Sustainable wetlandmanagement means accepting and optimizingthe different uses for wetlands and their asso-ciated watersheds.

n Precautionary Principle. “It is better to be safethan sorry.” Avoid an activity with an assumeddetrimental environmental impact, even whenscientific evidence cannot yet prove that theimpact will occur. And if detrimental impacts

7 OECD, 1996.

BOX 4.THE KIHANSI HYDRO PROJECT AND THE SPRAY TOAD

The Kihansi Hydro Project—a $260 million project to supply electricity to Tanzania—was financed by the World Bank, theGovernment of Tanzania, the European Investment Bank, and a number of bilateral donors. The project was com-pleted in 2000. Water was diverted from the Kihansi gorge through a tunnel to drive the turbines. Consequently, flows inthe gorge have been drastically reduced and the area of wetland in the gorge receiving spray has declined by 98percent.

The project received an A rating and a full EA was carried out. The EA noted that the ecology of the gorge would besignificantly impacted by the reduced water flows but, at that time, the existence of the Kihansi Spray Toad wasunknown and the project went ahead. The toad was discovered in 1996 when further studies were being conductedfor an EMP.

Various measures were initiated to save this unique toad. A captive breeding program has been carried out since2000 at the Bronx Zoo. After some initial problems, toad numbers have now started to increase. A pilot artificial spraysystem has been installed in the gorge to mimic the effect of the falls and restore some of the original habitat, andhydrological and ecological monitoring has been set up in the area. A search has been mounted for other habitats ofthe Spray Toad. A new project is being developed to manage the environment in the wetland area. It includescomponents to build management capacity in government institutions and to educate the general public aboutenvironmental issues.

Source: World Bank. 2001. Supporting the Web of Life: Biodiversity at the World Bank. Washington: World Bank.

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WETLANDS MANAGEMENT

BOX 5.THE PANTANAL

Bordered by Brazil, Paraguay, and Bolivia, the Pantanal is one of the world’s largest wetlands. It sustains flows in theParaguay River in both the wet and dry seasons, and supports a diverse assemblage of birds (650 species), fish (400species), and other biota. Tribal groups, numbering about 150,000 people, are highly dependent on these wetlandsfor their livelihoods, including food, transportation, and shelter. The wetlands also provide flood control and waterpurification services to millions of people downstream.

In the late 1980s, the governments of Argentina, Bolivia, Brazil, Paraguay, and Uruguay proposed a commercialwaterway through the Pantanal to provide year-round navigational access from inland regions to the sea. The eco-nomic study that accompanied this proposal did not include the social and environmental costs arising from theproposed channel straightening, deepening, and stabilization. Subsequent studies showed that the losses arising fromreduced wetland flooding and more rapid transmission of flood peaks would substantially offset the economicbenefits. Perhaps more importantly, the indigenous groups affected by the proposal mounted a worldwide protestbased on their exclusion from the planning of the project. As a result of these concerns, the Brazilian federal environ-mental agency suspended work on the plans within Brazil, and the Brazilian court system agreed that indigenousgroups had not been consulted sufficiently as required in the constitution.

are to be expected from project activities, checkthat measures are taken to mitigate impacts,even if they are not certain.

n No-Net-Loss Principle. If a development destroysor impairs an area of wetland after an assess-ment shows that there were no feasible alter-natives and the net benefits outweighed the costs,then the development plan should seek to re-tain the functions of the wetland as much aspossible and establish an equivalent wetlandelsewhere (Box 6). This is consistent with theBank’s O.P 4.04.

n Principle of Restoration. Wherever possible,previously degraded wetlands should be re-stored, if it can be shown through studies thatsome of the original functions of the wetlandcan be reestablished. The creation and restora-tion of wetlands is becoming technically andecologically feasible for a few types of wetland,such as freshwater marshes (Box 7) and tidalmarshes on low-energy coasts.

Project proposals can involve conversion of part orall of the wetland to an alternative use, or an up-stream development that can affect the wetlandthrough changes in flow (including groundwaterflows), increases in pollution, and the possibility ofthe introduction of alien flora and fauna species.Normally a small number of development options

are generated with input from the affected stake-holders. These options can then be assessed for theireconomic, social, and environmental effects.

ECONOMIC ANALYSIS

The choice of the preferred development option willdepend partly on an economic analysis of the ben-efits and costs of the options, and partly on the so-cial and environmental values of the wetland. Thelatter are seldom quantified and incorporated intothe economic analysis, even in developed countries,although there is now good guidance on how to doso.8 Nevertheless, quantification of major ecosys-tem services can provide important insights intowhich development option is appropriate. For ex-ample, an analysis of wetlands in northern Nigeriashowed clearly that the economic losses to wetlandusers from diversion of water to an upstream irri-gation scheme would at least be comparable to theeconomic benefits from the new irrigation area (Box8). Other noneconomic costs, such as social disrup-

8 World Bank (1998). Dixon, J.A., L.F. Scura, R.A. Car-penter, and P.B. Sherman. 1986. Economic Analysis of En-vironmental Impacts. London: Earthscan Publications.Also Chapter 6 in Belli, P., et al. (2000).

22


9 See World Bank (1998b).

BOX 6.WETLAND MITIGATION BANKING: AN INNOVATIVE APPROACH

Wetland mitigation banking provides an innovative, market-oriented approach to balancing the pressures for convert-ing valuable wetlands to high-intensity uses with the need to preserve the ecosystem functions provided by wetlands. Itis defined as the “restoration, creation, enhancement, and (in exceptional circumstances) preservation of wetlandsand/or other aquatic resources, expressly for the purpose of providing compensatory mitigation in advance of autho-rized impacts to similar resources.” If one wetland is to be destroyed through a change in land use, a fully compensat-ing wetland is developed to replace the lost ecosystem services. These “new” wetlands are taken from wetlandbanks—typically large wetland areas with agreed ecosystem values—under regulatory agency approval.

Estimating the value of an ecosystem is not easy and, in practice, most credits and debits have been measuredsimply in terms of the area of various classes of wetlands. Although area is a crude measure of value, it still allows theloss of many small wetlands to be accumulated into the establishment of a larger, ecologically superior wetland thatcan be better managed.

The approach has proven to be popular in the United States, with over 100 banks now in operation. Most banks areoperated by the same organizations, such as state highway departments that are carrying out the land use conver-sion. Until recently, there were few banks operated by the private sector where general developers could purchasecompensatory wetland credits. Now, under encouragement from the federal government, several watershed-basedwetland initiatives include private or publicly sponsored commercial banks.

In spite of its increasing popularity, there are some important unresolved issues with wetland mitigation banking. Thetiming of receipt of credits is central to full private sector involvement. If mitigation banks are constructed in advanceof wetland losses, commercial bank entrepreneurs require that they receive financial credits before replacementwetlands are fully functioning or self-maintaining. Also, the replacement wetland needs to be sustainable in the longterm if it is to be truly compensatory. This may require legally enforceable conditions on the long-term management ofthe replacement wetland. Finally, there are few satisfactory tools available for measuring the ecosystem servicesprovided by a wetland, and so the issue of agreeing on compensation for a destroyed wetland is subject to consider-able uncertainty and negotiation.

Source: Davis, M. 1995. “A More Effective and Flexible Section 404.” National Wetlands Newsletter 17(4).

tion to groups dependent on the wetlands and dis-ruption of water-bird habitat, were not quantified.

Economic analysis provides only one of the inputsto the decision regarding which development/con-servation option to select. To be seen as fair andhave local support, the decision will inevitably be aconsultative process that must involve all stakehold-ers. Given the diversity of functions provided bywetlands and the inter-connectedness of wetlandswith their surface watersheds and groundwatersystems, it is essential that any interventions thatmay affect a particular wetland be based on a thor-ough understanding of the ecological functions ofthe wetland and the consequent sensitivity of thosefunctions to changes likely to be induced by Bank-funded projects. This is an essential component ofmaking sure that the parties involved in these trade-offs understand the probable consequences of dif-ferent interventions.

MONITORING AND INDICATORS

Once a decision has been made about the preferredoption, there will need to be monitoring of the im-pacts of the proposed development on the function-ing of the wetland.9 Indicators of wetlandfunctioning should be developed as part of the imple-mentation process. A monitoring program shouldbe designed during project preparation to gatherthe information needed to quantify these indicators.The choice of indicators should be undertaken withinput from local communities so they can becomepart of the ongoing implementation and trackingof the project.

Wetlands are responsive to many other factors apartfrom those arising from the development. Conse-

23

WETLANDS MANAGEMENT

quently, the monitoring program needs to be de-signed to allow the effects of exogenous factors, such

as climate variability and climate change, to be sepa-rated from the effects of the development project.

BOX 8.VALUING ECOSYSTEM SERVICES: THE HADEJIA-NGURU WETLANDS

The Hadejia-Nguru wetlands in northern Nigeria occur at the junction of the Hadejia and Jama’are rivers, downstreamof existing and proposed irrigation schemes. During the rainy season, the wetlands are formed by annual flooding ofinactive sand dunes. The wetlands are important for wildlife conservation and also support a range of economicactivities, including wet-season and dry-season agriculture, fishing, fuelwood collection, livestock rearing, and forestry.Local people also use wild foods from the wetlands for sustenance, and obtain drinking water from shallow aquifers.Through the combined effects of drought and upstream water extraction, the wetlands have shrunk in recent yearsfrom 2,350 km2 in 1969 to 413 km2 in 1993.

One study put the economic value of the agricultural/fishing/firewood benefits provided by the wetlands at between846 and 1275 Naira per hectare. A later study put the loss of groundwater recharge benefit for dry-season irrigators at106,000 Naira per annum, and 1,146,000 Naira per annum for domestic water supply for a 1m drop in groundwaterlevel. The latter study did not include all the environmental benefits provided by recharge, let alone other environmen-tal benefits such as habitat provision for water birds and provision of wild foods for local populations. Overall, thestudies show that even these losses from a reduction in downstream wetlands are comparable to, and usually greaterthan, the benefits from proposed upstream irrigation schemes.

Source: Acharya, G. 2000. Approaches to valuing the hidden hydrological services of wetlands ecosystems. Ecological Economics 35:63-74.

BOX 7.RESTORING THE DELTAIC WETLANDS OF THE NORTHERN ARAL SEA

The decline of the Aral Sea began in the 1960s as increasing amounts of water were diverted—mainly for irrigation—from the inflowing rivers, the Amu Darya and Syr Darya. Between 1960 and 1996, the surface area of the sea declinedby some 50 percent and the sea level dropped by 16 meters. In 1990, the Aral Sea split into a small Northern Aral Sea(NAS) and a Large Southern Aral Sea (LAS) as the waters receded.

Today, fish production in the Syr Darya delta and the NAS is virtually extinguished, as well as hay production thatbenefited in the past from natural flooding along streams, lakes, and wetlands. The ecological system has deterio-rated, affecting both people and wildlife. Dust and salt storms occur often, and local climatic changes are takingplace around the sea. It is becoming difficult to locate adequate and safe drinking water supplies, and human healthproblems have increased sharply. Tens of thousands of jobs were lost in the former fishing, agriculture, and servicesectors. Huge tracts of agricultural lands were degraded by windborne and waterborne salt from the rivers, soil,groundwater, the desiccated seabed, and dried-up wetlands.

The delta area, wetlands, and lakes near the NAS could be rehabilitated by building a dike across the Berg Straitconnecting the NAS to the LAS. Using limited local resources, this approach was tested by the creation of a temporarydike in the Berg Strait in 1992 and then again in 1996. It demonstrated that a partially restored NAS will have a muchlower salinity than the LAS, thereby improving the environmental situation, improving fisheries potential, and in particu-lar, enhancing the socioeconomic conditions in the area.

By rehabilitating the NAS, the project would address the root cause of the environmental degradation in the Syr Daryadelta. This would improve agricultural, livestock, and fishery production in the river basin and the delta area. The mainenvironmental benefits of the project include the restoration of the ecosystem and improvements in fishery reproduc-tion conditions in the NAS and in the lakes. The positive impact of the NAS on microclimate and air quality wouldpositively affect soil salinity, soil fertility in the delta area, human and animal health, vegetation, and wildlife.

A World Bank-funded project commenced in 2001 to construct the Berg Strait dike, rehabilitate some control structureson the Syr Darya River, upgrade the Chardara Dam, develop the fisheries industry in the NAS, and install a monitoringand assessment capability.

Source: Project Appraisal Document (P046045), Syr Darya Control and Northern Aral Sea Phase-I Project. Washington:World Bank.

24


Indicators of change such asextent of poverty, annualwithdrawals of ground andsurface water, or threatenedspecies as a percent of totalnative species can be used.The United Nations Commis-sion for Sustainable Develop-ment has done much work onindicators to measure sus-tainable development.10 Box9 gives an example of indica-tors used to monitor theimpacts of a wetlands man-agement program imple-mented in the Baltic SeaRegion with pilot projects inRussia, Latvia, Estonia,Lithuania, Poland, and Ger-many. It shows how a consis-tent structure can be set up to link causes ofchange—in this example, control of illegal forestryand fishing—with the impacts of those changes. It isimportant to ensure consistency between indica-tors used for the monitoring programs and indica-tors used during the environmental assessment (EA)process so that changes can be measured from anagreed baseline.

Data are gathered for these indicators through amonitoring program. Field monitoring by rangers,

scientists, and local residents can be supplementedby modern technologies such as remote sensing andtelemetric data management. Responsibility formonitoring should be clearly assigned to specificinstitutions or parties, which may be governmentagencies, NGOs, or private organizations with thecapacity to undertake the data collection and inter-pretation.

BOX 9.INTEGRATED COASTAL ZONE MANAGEMENT INDICATORS IN THE BALTIC SEA REGION

The HELCOM Management Programs for Coastal Lagoons and Wetlands, led by the WWF, includes pilot projects inlagoons in Estonia, Latvia, Lithuania, Russia, Poland, and Germany. The main goal of the project is to introduceIntegrated Coastal Zone Management (ICZM) principles into the management of the Baltic Sea.

Some regions are highly polluted and industrialized, while others have high biodiversity values that are being threat-ened. Many of the problems have not been solved because of lack of institutional capacity. The OECD (Pressure,State, Response) framework was used in the monitoring programs. The indicators were identified through workshopsand meetings with the stakeholders. Most important indicators are related to ecotourism; fisheries; hunting, birds, forest,and fauna; pollution and landfills; land and natural resources; and water quality, water treatment, and drainage.

A Driving Force Indicators (DFI) matrix (Table 4) shows how problems and their causes are related. In a second matrix(Table 5), the State and Response Indicators (SRI) are linked by “targets” and proposed “actions.” Part of the matricesfrom the Latvian example are used here to illustrate the principles of the approach.

Source: Gladh, L. WorldWide Fund for Nature, Sweden

Fishermen on the Shire River, Malawi

Pho

to b

y Ja

ne T

urp

ie

10 United Nations (1996).

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WETLANDS MANAGEMENT

CONSTRUCTED WETLANDS

costs for small communities and even for upgrad-ing of larger treatment facilities. In addition, thesesystems can provide valuable wetland habitat forwaterfowl and other wildlife, as well as areas forpublic education and recreation.

Because of the build-up of contaminants in sedi-ments and aquatic plant tissues, wetlands con-structed for contaminant removal need to be activelymanaged. Nutrients and other contaminants willbe released back into the water as the plants dieand decompose unless the wetland management in-cludes periodic harvesting and productive use orsafe disposal of the plant material. Contaminantsabsorbed in the sediments also will be flushed outduring large flow events unless the wetland is spe-cifically designed to bypass large flows or the man-agement plan includes removal and safe disposal

TABLE 5.S-R INDICATOR MATRIX

State Indicators Targets Actions Response Indicators

nNumber of inspectors Develop local business Launch “business nNumber of local enterprisesincubator” using business incubator

nManagement plans Provide control and Establish administra- nNumber of new inspectorselaborated YES/NO decisionmaking bodies tion of Kemeri

for area National Park

nEmployment in tourism Establish administra- nNumber of training activitiestion for the project for local people

nEmployment in agriculture area

Establish fund for the nPercent of local people familiarproject area with nature protection idea

Hire inspectors

TABLE 4.DRIVING FORCE INDICATOR MATRIX

Problems Causes Driver Indicators

Illegal forest cutting and fishing Lack of controlling bodies nUnemployment rate

Lack of coordination nGDP per capita in agriculture

No management plans nCoastal area with buildings/total

Unemployment area market

Wetlands can be constructed to provide specific eco-system functions. In particular, they have been usedfor treating and recycling wastewater, resulting inimproved water quality and often valuable wild-life habitat. Although wastewater treatment is themost common use of constructed wetlands, theycan also be used for removal of toxicants and in-dustrial wastes and for recharging groundwatersystems.

Different wetland technologies are now available,such as various forms of ponds, land treatment andwetlands systems. Considerable experience has beengained over the years on improved methods for de-signing and operating constructed wetlands. Thisexperience, together with results reported in the re-search literature, suggest that constructed wetlandsoffer considerable savings in wastewater treatment

26


of the sediments. The health of these wetlands needsto be closely monitored, because constructed wet-lands can be subjected to large loads of toxic con-taminants that can damage the flora and fauna ofthe wetland that provides the ecosystem services.

Agricultural and industrial chemicals can cause thedeath of microbes and macrophytes unless the dis-charges into the wetlands are closely monitored andregulated.

CONCLUSION

Wetlands provide a wide range of ecological func-tions that support the livelihoods of local commu-nities as well as provide regional and global benefits.They provide food and fiber locally, flood controland groundwater recharge regionally, and migra-tory bird habitat and nutrient recycling globally. Inthe few studies undertaken to date, the economicvalue of these functions is surprisingly high—com-parable, in some studies, to the benefits from pro-posed development activities that would haveaffected the wetlands.

About half the world’s wetlands were destroyedduring the 20th century by agricultural develop-ment, urban expansion, pollution, and changes inriver flows. There is an increasing appreciation in

the developed world of the importance of retainingwetlands; options include construction of artificialwetlands for specific purposes (such as treatmentof effluent), as well as innovative schemes to com-pensate for any wetlands destroyed by development.Projects financed by the World Bank can affect wet-lands through inundation, conversion to alternateland uses, changes in flow regimes, increases inpollution, and drawdown of groundwater. Conse-quently, damage to wetlands can trigger a numberof safeguard policies. The Bank does not supportprojects that would result in the significant conver-sion or loss of natural habitat, such as wetlands,unless there are no feasible alternatives, the ben-efits substantially outweigh the environmental costs,and suitable mitigation measures are put in place.

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WETLANDS MANAGEMENT

FURTHER INFORMATION

The following texts provide general background onwetlands:

Firehock, K. L., J.V. Middleton, K.D. Starinchak, C. Will-iams and L. Geoff. 1998. Handbook for WetlandsConservation and Sustainability. Gaithersburg,MD: Izaak Walton League of America.

Acreman, M.C. and G.E. Hollis, eds. 1996. Water Manage-ment and Wetlands in Sub Saharan Africa. Gland,Switzerland: IUCN Wetlands Programme.

OECD. 1996. Guidelines for Aid Agencies for Improvedand Sustainable Use of Tropical and SubtropicalWetlands. Paris: OECD.

Roggeri, H. 1995. Tropical Freshwater Wetlands: Guide toCurrent Knowledge and Sustainable Management.Dordrecht / Boston / London: Kluwer AcademicPublishers.

Information on wetland assessment can be foundin:

Koudstaal, R., and R. Slootweg. 1994. Wise Use of Wetlands:A Methodology for the Assessment of Functionsand Values of Wetlands. Delft, The Netherlands:The Wetland Group.

Howe, C.P., G.F. Claridge, R. Hughes and Zuwendra. 1991.Manual of guidelines for scooping EIA in Tropi-cal Wetlands. PHPA/AWB Sumatra WetlandProject Report No. 5. Asian Wetland Bureau.Bogor, Indonesia: Department of Forestry, Indo-nesia.

World Bank. 2002. Wetlands and Environmental Assess-ment. Environmental Assessment SourcebookUpdate No 28. Washington: World Bank.

Two useful documents on assessing environmen-tal values provided by wetlands are:

World Bank 1998a. Economic Analysis and Environmen-tal Assessment. Environmental AssessmentSourcebook Update No. 23. Washington: WorldBank.

Belli, P., J.R. Anderson, H.N. Barnum, J.A. Dixon and J-PTan. 2000. Economic analysis of investment op-erations: analytical tools and practical applica-tions. Washington: World Bank.

Information on monitoring and indicators can befound at:

World Bank. 1998b. Guidelines for Monitoring and Evalu-ation for Biodiversity Projects. Environment Pa-pers No. 65. Washington: World Bank.

United Nations. 1996. Indicators of Sustainable Develop-ment: Framework and Methodologies. New York:UNCSD.

The following reference provides a good overviewon constructed wetlands:

Hammer, D.A. ed. 1990. Constructed Wetlands for Waste-water Treatment: Municipal, Industrial, Agricul-tural. Chelsea, Michigan: Lewis Publishers.

Some useful websites dealing with wetlands include:

IUCN Wetlands Programmehttp://www.iucn.org

Ramsar Convention Bureauhttp://www.ramsar.org

World Wide Fund for Naturehttp://www.panda.org

Wetlands Internationalhttp://www.wetlands.org

US Society of Wetland Scientistshttp://www.sws.org/

etlands management echnical note g.3 ater resources and...

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