Transcript Slide 1

Regional Climate Change
Water Supply Planning Tools for
Central Puget Sound
Austin Polebitski and
Richard Palmer
Department of Civil and Environmental Engineering
University of Washington
Seattle, WA 98105-2700
www.tag.washington.edu
Regional Motivation
 Multiple agencies and organizations
working together to develop data,
information and pragmatic tools to
assist in water resource and supply
planning activities in the region.
 Regional Water Demand Forecast
 Water Supply Source Alternatives
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Climate Change
Reclaimed Water
Source Exchange Strategies
Small Water Systems
Tributary Streamflows
 Research Goal: Provide climate
impacted streamflows and
meteorological data to Water
Demand and Water Supply
Committees
Regional Motivation
 Multiple agencies and organizations
working together to develop data,
information and pragmatic tools to
assist in water resource and supply
planning activities in the region.
 Regional Water Demand Forecast
 Water Supply Source Alternatives





Climate Change
Reclaimed Water
Source Exchange Strategies
Small Water Systems
Tributary Streamflows
 Research Goal: Provide climate
impacted streamflows and
meteorological data to Water
Demand and Water Supply
Committees
Deliverables
 Meteorological Variables
 Technical memorandum documenting the methods used,
key assumptions, QA/QC efforts and results.
 Database of climate variables for defined scenarios and
future years for specific sites.
 Streamflow Data
 Technical memorandum - for each portion of the WRIAs,
documenting the methods used, key assumptions, model
calibration and validation, QA/QC efforts and results.
 For each of the climate change scenarios, database of
projected streamflows into local reservoirs.
 For each of the climate change scenarios, database of
projected streamflows associated with environmental flows
or other operational components.
 Other Support
 Framework for estimating potential future climate change
impacts on municipal water demand and supply.
 Support to Municipal Water Demand Forecast and Water
Supply Assessment Advisory Committees.
 Cloud cover Study
 Groundwater Study
Building Blocks
 Conceived as Team Building and as an ‘Ice-Breaker’
 became extended, heated issue.
 Uncertainty: As with other science, our understanding
will improve with time, uncertainties exist, but much is
known
 Impacts organized into six areas:
 Temperature
 Precipitation
 Snowpack and Glaciers
 Streamflows
 Sea Level Rise
 Salmonid Habitat
 Areas of interest
(Source:
http://agexted.cas.psu.edu/FCS/mk/imag
es/BuildingBlocks.jpg)
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Global trends
National trends
Pacific Northwest trends
Puget Sound Region
 Available at: http://www.climate.tag.washington.edu
 Building Block 1 – The global average
temperature has increased during the 20th
century and is forecasted to increase in the
21st century.
 Building Block 13 –Climate change, as
described in Building Blocks 1-12, is
forecasted to contribute toward stream flow
and temperature conditions that have been
shown to negatively impact freshwater and
estuarine habitat of most species of
salmonids in the Puget Sound watersheds.
Tech Memo #1 - Literature Review
 Climate Change Primer
 Historical perspective of
incorporating climate
change into water
resources planning
Discussion of GCMs,
Downscaling Methods, and
Hydrology Models
 Incorporating uncertainty
Tech Memo #2 – Downscaling Methodology
 Details downscaling method in
two different formats:
10
January Average Temperature (C)
January Average Temperature (C)
 An in-depth discussion of the
method and a case-study provided
as a journal paper
 An overview discussion of the
method accompanied by a process
diagram
HadCM3 Cell (47.5, -120.0)
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Regional Cell (47.5625,-121.8125)
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4
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0
0.2
0.4
0.6
0.8
Non-Exceedance Probablility
1
1.2
10
Regional Cell (47.5625,-121.8125)
Snoqualmie Falls
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0.2
0.4
0.6
0.8
Non-Exceedance Probablility
1
1.2
Tech Memo #3 – Website and Database
Functionality
 Details construction and
functionality of web-based
database for climate
variables
 Website contains historic and
climate impacted precipitation
and temperature data for 15
meteorological stations within
planning area
 Simulated historic and
climate impacted streamflows
are accessible, plotting
function is nearing completion
Tech Memo #4 – Meteorological Variables
Change in Average Monthly Temperature Relative to Historic (WY 1928 - 2004)
2025
Meterological Stations in WRIAs 7 - 10
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5
5
4
4
3
3
Degrees C
6
2
 Was recently approved
by committee and is now
available online
GISS_B1 2000
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IPSL_A2 2000
Ensemble Average
Historic
Echam5_A2 2025
Change in Average Monthly Temperature Relative to Historic (WY 1928 - 2004)
2050
Meterological Stations in WRIAs 7 - 10
GISS_B1 2025
IPSL_A2 2025
Ensemble Average
Historic
Change in Average Monthly Temperature Relative to Historic (WY 1928 - 2004)
2075
Meterological Stations in WRIAs 7 - 10
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5
5
4
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3
3
Degrees C
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2
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GISS_B1 2050
IPSL_A2 2050
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 Contains a quality control
discussion of data and
computer code used in
generation of the data
 Provides an assessment
of future projections and
likely impacts to
temperature and
precipitation for our region
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 Evaluation of impacted
climate data
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Degrees C
Change in Average Monthly Temperature Relative to Historic (WY 1928 - 2004)
2000
Meterological Stations in WRIAs 7 - 10
Month of Year
Ensemble Average
Historic
Echam5_A2 2075
GISS_B1 2075
IPSL_A2 2075
Ensemble Average
Historic
Tech Memo #5 – Streamflow Generation
 Evaluation of climate impacted
streamflows
Streamflow @ 12093500
2000
 Contains a detailed discussion on
model development, calibration,
and comparison to historic
observed records
 Provides an assessment of future
impacts to streamflow for the TriCounty Region
1800
1600
1400
Flows (cfs)
1200
1000
800
600
400
 Is undergoing final revisions but
likely approved in October
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Oct
Nov
USGS_Median
Dec
Jan
Feb
DHSVM_Median
Mar
USGS_25th
Apr
May
Jun
USGS_75th
Jul
DHSVM_25th
Aug
Sep
DHSVM_75th
Average Monthly Flows at Tolt Inflow
700
Average Monthly Flows (cfs)
500
400
300
200
100
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600
0
Oct/1990 Oct/1991 Oct/1992 Oct/1993 Oct/1994 Oct/1995 Oct/1996 Oct/1997 Oct/1998 Oct/1999 Oct/2000 Oct/2001 Oct/2002
Tolt_Inflow
Tolt_USGS
Tech Memo #6
Final Summarizing Document
Integrate documents produced by
CCTC
Make suggestions for incorporating
available data and uncertainty into
water resources planning
Use of Data in Other Research
Tract 2800
24000
 Water Supply Systems Modeling
and Impacts
20000
16000
12000
0
 Each utility is evaluating system yield
with climate impacted data
20
30
40
50
60
70
25000
20000
RMSE Pooled = 10.55% RMSE Indiv = 4.22%
15000
 Regional water supply will use
temperature and rainfall elasticities
0
10
20
30
40
50
60
70
35000
Tract 3000
30000
RMSE Pooled = 7.56% RMSE Indiv = 5.86%
20000
25000
 Wastewater Management
 Evaluate base waste water demand
with regional demand model
0
10
20
30
40
50
60
70
0
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-2
Change in Firm Yield (MGD)
 Evaluate impacts of climate change
on extreme rainfall events and
associated runoff
10
Tract 2900
 Water Demand Modeling
 Potential Impacts of Climate
Change on Flood Related Issues
RMSE Pooled = 16.2% RMSE Indiv = 4.16%
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2000
GISS_B1
Linear (GISS_B1)
2025
ECHAM5
Linear (ECHAM5)
2050
IPSL_A2
Linear (IPSL_A2)
2075
Ensemble
Linear (Ensemble)
 Over 20 half-day
meetings/ workshops
to establish study
objectives and
approach
 Significant
participation from over
15 regional agencies
and stakeholders
 Consensus achieved
 Results incorporated
into evaluation of
supply and demand
alternatives in regional
process
http://www.tag.washington.edu/projects/kingcounty.html