Transcript Water, Climate, Food, and Environment in Walawe Basin, Sri

Water Allocation
Scenarios
to explore Green Water Credits opportunities
Peter Droogers, SEI
Holger Hoff, SEI
Water Evaluation & Planning System
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SWAT
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WOFOST

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Supply analysis, basin scale
Detailed crop analysis
WEAP

Demand size allocation and benefits
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Possible questions to be answered
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How is blue water currently allocated between
different uses?
What unmet demands can be expected if current
trends are projected into the future?
What are alternative allocations to maximize benefits?
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Possible alternatives
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How should reservoirs be operated to maximize
benefits?
What would be the downstream effects of additional
reservoirs (Mutonga-Grand Falls) ?
What is the effect of erosion control on reservoir
siltation and hydropower generation?
What is WEAP

Old: Water Evaluation and Allocation Program
 Water Evaluation And Planning system
Use the
View bar to
switch
between
your data
and its
results.
GIS layers
can be
added here.
Your can
zoom your
schematic
in or out
by sliding
the bar
here.
Use the menu to do standard
functions such as creating
new areas and saving.
You can click and drag elements of the
water system from the legend onto the
schematic directly.
Data are organized in a tree
structure that you edit by rightclicking here.
Use the
View bar to
switch
between
your
analysis
and its
results.
You can create multiple scenarios and use
this box to switch between them.
Enter or edit
your data by
typing it
here.
Your data
are shown
here as
either a
graph or a
table.
Data Requirements

Water supply, provided by SWAT model
• Time series data of riverflows for Tana and tributaries
• River network (connectivity)
• Reservoir and hydropower generation
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Water demand, to be provided by national
partners
• Time series data of sectoral demands
• Trends in population, economic development etc
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Complementary data
• households
• poverty rates in the upstream areas
Data Requirements

(continued)
Sectoral water demands
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Municipal, hydropower and other demand
• Aggregated by sector
• Disaggregated by population (e.g., use/capita,
use/socio-economic group)
Agricultural demands
• Aggregated by area (# hectares, annual wateruse/hectare)
• Disaggregated by crop water requirements
Ecosystem demands (in-stream flow requirements)
SWAT: Supply site
HRUs
sbs1997.WYLDMM
0
1 - 250
251 - 500
501 - 750
751 - 1000
1001 - 1250
1251 - 1500
1501 - 1750
1751 - 2000
2001 - 3000
0
25
50
100 Km
Tana Basin, Kenya
Green Water Credits
Conclusion
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Models:

SWAT
• Supply (generation of green water credits)

WEAP
• Demand (benefits from green water credits)



Explore scenarios
Proof of green water concept
SWAT, WEAP only support tools:


Socio-economic analysis
Policy support
Thank You