irrigation systems water savings - technical, economic and...
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B R S S E M I N A R S E R I E S P R E S E N T S :
Friday 18 November
Irrigation Systems Water Savings - Technical,Economic and Institutional Issues
Dr Shahbaz Khan - The Water for a Healthy CountryFlagship, CSIRO
In the Murray Darling Basin it is generally accepted that there will be lesswater available for irrigated agriculture in the future and that the availableresource must be used more efficiently. Water for environment or newirrigation developments needs to be resourced through irrigation watersavings at the farm and system levels. However water savings from one partof the system may lead to higher water use in another part of the system andthe overall improvement may be negligible.
The key to achieving substantial water savings lies in the assessment andhydrologic ranking of water saving options in a “whole of system” context.This seminar describes results of a major water use efficiency study in theMurrumbidgee Valley, Australia. Benefits of a systems approach aresummarised through a hydrologic and economic evaluation of water savinginterventions at the field, irrigation area and catchments levels. Supply anddemand theory is used to explore how to internalise the social costs createdby irrigation activity and saving of associated losses that burden the local andregional environment.
11.00am - 12:00noon (morning tea at 10:45am)Edmund Barton Conference Centre (in the courtyard)
Department of Agriculture, Fisheries and ForestryEdmund Barton BuildingKings Avenue, Canberra
Bookings not required.Parking can be a problem, we suggest taking public transport or a taxi.
For further details, please call the BRS Seminar Coordinator on 6272 4011.
For further information on BRS Seminars or to obtain papers/presentations supplied byprevious seminar presenters, please visit our website at: www.brs.gov.au/brsseminars
Click to edit Master subtitle style
Irrigation Systems Water Savings: - Technical,Economic and Institutional Issues
Shahbaz Khan
Stream Leader Irrigation Systems/Professor of Hydrology
Acknowledgements: Water for a Healthy Country Flagship, ACIAR
and Pratt Water
www.csiro.auPresentation Objectives
ß Using examples from Australia and China
ß Two examples of options and relative size of watersavings in large irrigation systems
ß Issues associated with realising these water savings
ß Suggest a possible way forward – how to increase waterproductivity at the system level
www.csiro.au
CLIMATE VARIABILITY and CHANGERainfall
CATCHMENTIRRIGATION
GROUNDWATER
WETLAND
RIVER
ESTUARY
SEADAM
Key Pressure Points for Increasing WaterProductivity in Rice Based Systems
www.csiro.auWater losses and gains are part of the water cycle
gain
loss
www.csiro.au
5125
14
17
3924
15
1096
7
1217
2536
22
194
1181
21
466
2038
-99590
164282386
#
Wagga Wagga
#
Narrandera
#
Darlington Pt
#
D/S Hay Weir
#
D/S Balranald Weir
Inflow / Outflow (GL)
Diversions (Gl)
Evaporation (GL)
Net Change (GL)
1880
1945
1830
2216
#
Burrinjuck Dam
#
Blowering Dam
Murrumbidgee System Water Account (1991)
www.csiro.auDecline in Deeper Groundwater Pressures (1990-2000)
The overall basis for the groundwater allocation is the averageannual recharge to each groundwater source as follows:(a) 65,000 ML/yr to the Shepparton (over 50.000 ML from RiceGrowing) and,(b) 335,000 ML/yr (over 90,000 ML/yr from Channels) to theCalivil and Renmark.Current groundwater use is around 200,000 ML/year.
www.csiro.auOn-farmMurrumbidgee &ColeamballyIrrigation Areas
EnvironmentalBenefit
Soil + groundwater monitoring
0.1 to 3 ML/ha
Irrigation flowmonitoring
0.2 to 2.5 ML/ha
Laser levelling0.1 to 0.4 ML/ha
Lining on-farmchannels
1 to 4% of supply
Relocating rice tosuitable locations
0.1 to 3 ML/ha
ConvertingIrrigationSystems
2.0 to 4.0 ML/ha
_ accessions to watertable
Water Savings
_ subsurface drainage_ surface drainage
Incr
easi
ng in
vest
men
t
$50
- $7,
000
/ML
_ accessions to watertable_ salinity
www.csiro.auEnvironmental
Benefit
Monitoring anddelivery
100 – 200 GL
Closer monitoringand delivery
10 – 50 GL
Piping channels
15 – 70 GL
Reducingevaporation losses
20 – 50 GL
Incentives forefficient water use
10 to 30% increase in water security
Providing ecosystemservices
reduction in rechargeabatement cost
match demand with supply
_ accessions to watertable
Water Savings
production andenvironmental benefits
Incr
easi
ng in
vest
men
t
$500
- $7
,000
/ML
Sealing leakychannels
_ accessions to watertable_ salinity
promotion of water efficientcommunity
Off-farmMurrumbidgee &ColeamballyIrrigation Areas
www.csiro.au
Potential Water Savings (ML/ha)Potential Water Savings (ML/ha)For Converting Flood to Pressurized IrrigationFor Converting Flood to Pressurized IrrigationSystems for Maize in the MurrumbidgeeSystems for Maize in the Murrumbidgee
mm
Water Savings Vary Across the Landscape
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Channel Seepage Varies Spatially and Temporally
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-120
-100
-80
-60
-40
-20
0
20
40
60
0 5 10 15 20 25
Year
NP
V (
'000
)
BaselineDecreased BenefitsIncreased Costs
Cost Benefit of Conversion from Contour Bay to CentrePivot ( 3 circles)
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Capital investment and total water savings byhigh-tech irrigation technologies
0
5000
10000
15000
20000
25000
30000
40905 58305 60610 61810 63630 65385 66135 81821 82121
Total Water Savings (ML)
Ca
pit
al
($/M
L)
Lateral MoveCentre Pivot (towed)Centre Pivot (fixed)Subsurface Drip
www.csiro.auCosts of Saving Channel Losses
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
0 8000 16000 24000 32000 40000
Total (ML) Saved
Cap
ital
Co
st(
$/M
L)
Sav
ed
Bentonite Rice Hull Ash Water Sludge
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Breakeven water chargesfor saved water over 30 years project life
Bentonite
0
50
100
150
200
250
300
350
0 5000 10000 15000 20000 25000 30000 35000 40000
Total Water Saving (ML)
Bre
akev
en P
rice
of
Wat
er (
$)$/
ML
Alternatively every water user pays $30/ML for access to more efficient water supplies
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Efficiencies in Murrumbidgee Irrigation AreaGL 2000/01
Irrigation water(surface)
Irrigationwater
(groundwater)
Rainfall
Regionalgroundwater
1048
439
26
Off-farmconveyance
90%95%
On-farmconveyance
88%90%
Fieldefficiency
89%95%
Edge offarm
836
946
1162Rootzone
Edge offield
Water useefficiency
Waterproductivity
87%91%
798t/GL836
Economicreturn
$198K/GL$207
1419ET
Shallowground-
water118
1,300,241tonnes
$322m profit
Total watersupply 1630
18 Applyingproject results
Current
75 GL saved +$14m profit
www.csiro.au
Saving Seepage Losses – AustralianContext
ß Canal Lining - $1500 to $4000/ML saved
ß For saving 35000ML capital investment @2000/ML is $ 70 Million
ß Water Productivity is $100-200 per ML
ß Permanent Trading Price ~$ 800-1200 per ML
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Yellow River
Railway Line
River System
River Bank
Water Savingsin Liuyuankou Irrigation System in China
www.csiro.auCropping Pattern in the LIS
Rice, 4909, 22%
Maize, 8033, 36%
Cotton, 8479, 38%
Soybean, 893, 4%
Summer Crops, Area in ha, % of total crop
Winter Wheat 20,000 ha
Cropping Intensity 1.44
www.csiro.au
0.62
0.41
0.13
0.04
0.16
0
5000
10000
15000
20000
25000
30000
Agriculture Crops Fallow Land Bare Soil Water Others
Land Use Classes
Are
a (H
a)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
ET
(M
cM)
Area ET
2 September 1990
Actual ET Vs Land Use for LIS, China
www.csiro.au
Net Drawdown After 10 YearsCanal Lining Only
%age WT ET reduction
14.2% on the whole
of the model domain
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Net Drawdown After 10 YearsCanal Lining and Pumping ARL
%age WT ET reduction
45.3 % on the whole
of the model domain
www.csiro.auCosts of Canal Lining and Water Saving
ß Estimated canal to be lined = 60 km
ß Total Savings 20 MCM
ß Total cost = 76.76 million Yuan
ß Total O&M cost = 1.15 million Yuan/yr
ß Capital Cost of Water Saving per m3=3.8 Yuan
ß Water Productivity per m3=1.35 Yuan
ß Capital Cost/ML=AUS$619
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25.00
7.36
1.05
4.90
0.86
44.00
16.82
1.15
3.27
0.73
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
IRR (%) NPV (000' Yuan) BCR Pay Back Period Breakeven (ha)
Evaluation Criteria
Val
ues
Diesel Engine (15 HP)Electric Engine (2.2 KW)
Economics of Tubewell (based on most commonly used pumps)
Cost of GW PumpingIn China
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Possible Public-PrivatePartnerships to Water Savings
www.csiro.auThe Concession Deed Framework
ß Concession deed is provided for the regionalwater infrastructure project
ß Joint private and government entities are partyto the agreement
ß Construction and operation: terms andaccountabilities
ß Proportion of saved water allocated for regionaljobs & investment (but bulk of water goes to theenvironment)
ß Environmental obligations costed and includedin concession deed arrangement
www.csiro.auKey Benefits of Concession Approach
ß Allows leveraging of government funds withsignificant private sector investment
ß Risk transfer to private sector (cost of construction+ maintenance obligations)
ß Creates sustainable water savings for bothenvironment and regional development
ß Provides a model for other regional projects
ß Retains government ownership and bulk of water& other assets (revert to government at end ofperiod)
www.csiro.auPotential Hurdles
ß Water infrastructure viewed as aliability, not and asset
ß No natural “sponsor” for projects suchas this
ß Doctrine of allocating all savings toenvironmental/downstream flows
ß Securing agreement for access partof the savings for regional use
ß Institutional issues
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The Five-Step Feasibility Approach to Water SavingsAimed to Make Australia’s Irrigation to Lead the World
BiophysicalStocks andFlows
1WaterProductivity&EcosystemServices
2 SocialCultural &InstitutionalAspects
3EstablishA BusinessPlan
4 5Implement the Business Plan
In what keyareas doirrigationbusinessesdirectly andindirectlyrely on andimpact waterthroughoutthe valuechain ?
Key Drivers forWater & ResidualCycle
Key Water Uses
Key Water Impacts
What are theecologicalrisks andWUEopportunitiesfor irrigationbusinesses?
WUEOpportunitiesPrioritisedEcologicalRisks and
How thecommunitiesandorganisationscan be bestengaged inpursing thewatersustainabilitystrategy ?
Institutionaland SocialOpportunities
What is thebestbusinesscase forpursuingwatersustainabilitystrategy ?
Business Casefor Action
Setting theStrategic WaterBusinessDirections
A structureddeliverymechanismthat producestools forapplicationelsewhere
Templates forResilientIrrigationBusinesses&Environments
Input to OtherWaterPlanning and ManagementStrategies
New Science for Synchronising Irrigation Systems and their Operating Environments
Business Cases and Delivery Templates
x
Feasibility Step
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Future Challenges
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Supply ChargesSupply Charges
20052005
Total units of waterTotal units of water
20xx ?20xx ?
X?X?
20yy ?20yy ?
y?y?
True Cost of WaterTrue Cost of Water True Cost of SupplyTrue Cost of Supply
Environmental CostsEnvironmental Costse.g.e.g.1 to 4 Million/EC Credit1 to 4 Million/EC Credit0.5 to 1 $/ML/EC Credit0.5 to 1 $/ML/EC Credit
Demand Curve Demand Curve with Current Useswith Current Uses
Technologies to improve WUE
Managing Irrigation Efficiency at the System Level
14000 MCMConsumptive Use of WaterConsumptive Use of Water
MB, M
C ($/unit of wat er)
MB, M
C ($ /u nit of wate r)
>1000 $/ML
<30 $/ML
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In irrigation practice - water, costs andknowledge are interlinked
Costs
Water
Knowledge
Decrease water•Increase costs•Increase knowledge
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• Need to manage the system - salinity,surface and groundwater systems, water quality
• Need to distinguish between salinity impacts onrootzone (crop production) and surface /groundwater systems (environmental impacts)
• Need to understand and manage differencesbetween channel leakage (system problems) andirrigation practice (e.g. rice recharge)
Future Challenges
www.csiro.auPlanning Tools for Future Irrigation Systems
•Tools for reconfiguration of irrigation systems due toland retirement and water trading out in and out ofsystems
•Models for quantifying climate and engineeringinterventions impacts on local and basin water andsalt balances
•Planning and management instruments for costsharing among primary, secondary and tertiarystakeholders
www.csiro.auPolicy, Law and Governance Challenges
• Unified Legal Frameworks for water managementand water savings at different scales which leads toa water efficient society
• Harmonising the Environment and Irrigation andDrainage Acts
• Legislative changes to incorporate positive andnegative externalities of irrigation systems
• Cost sharing instruments between farmers and thewider environment – water leasing for anenvironment as an option for saving water
www.csiro.auConclusions
ß Whole of the system analysis is necessary toidentify “true” water savings for production and theenvironment.
ß Accurate measuring and monitoring systems fromriver to the plant levels are perquisite for realising“true savings”.
ß A top down (catchment to farm level) watersavings approach (“soft approach”) aimed atpublic-private sharing of cost and benefits isnecessary. Leasing environmental water may bean option.
www.csiro.auMaking Australian Irrigation As WorldMaking Australian Irrigation As World’’s Bests Best
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