2010 PNCWA Conference
Seattle’s Drainage & Wastewater Climate Change Adaptation Strategy
Gary Schimek
Manager, Drainage & Wastewater Division
Seattle Public Utilities
Outline
• Climate Adaptation Context
• Climate Vulnerability
• Seattle’s Adaptation Approach
• Conclusions
Context
• “(Climate) vulnerability is a function of location and capacity to cope”‐Cooperative Program on Water and Climate, “Climate Changes the Water Rules”
• “Adaptation is a process through which societies make themselves better
able to cope with an uncertain future”UNFCCC, “Impacts, Vulnerabilities and Adaptation in Developing Countries”
• “Countries will need to plan for adaptation with much greater rigor, focus
and urgency than has been the case until now ‐
aligning the actions of
public, private and NGO stakeholders in concerted effort.”Lord Nicholas Stern, “Shaping Climate Resilient Development”
Orientation
Sequim – 17”
Seattle – 37”
Cedar River Watershed – 100”
Hoh River Valley – 150-180”
Seattle’s Drainage and Wastewater System
• System Drivers:
• Combined Sewer Overflow
(CSO) and Stormwater
Permit Compliance
• Sediment cleanup
• Urban Flooding
• Urban flooding and climate
change:
• Significant life safety and
property impacts in ‘04,
‘06, and ‘07
• Projected climate change
impacts more intense
winter storms
• Historic system design =
25yr event
Historic Precipitation Analysis
• Extreme events mostly localized
and short duration
• No significant change in IDF
curves
• Weak increasing statistical
trend in occurrence of extreme
events
• Tendency toward increased
frequency of localized events
Projected Climate Impacts
Washington Climate Change Impacts Assessment (WACCIA)• 2009 report
• Produced by UW Climate Impacts Group (UWCIG) in partnership with
Washington State University and Pacific Northwest National Laboratory
• Stormwater
Infrastructure chapter
• Generally projections for increases in extreme high precipitation
(Rosenberg et al, 2009)
Climate Vulnerability is a function of:
(location and system specific impacts)
Operational & structural
Behavioral & sociological
Technical Political
Technological Legal & financial
InstitutionalCAPACITY TO COPE
LOCATION
AND
SPU’s
approach to drainage/wastewater adaptation
• Move beyond capital focused approach
• Bottom‐up, “no regrets”
• Identify operational adjustments
• Support applied research• Identify high priority impacts areas
• Collaborate• Experiment
• Build internal capacity• Create a flexible business portfolio
Identifying Priority Areas: Flood Prone Mapping
• Identify highest priority
flooding areas based on:
– impacts from recent storm events,
system knowledge, modeling
results, and complaint database
• Develop “fact sheets”
for the
most critical areas (2008)
• Conditioned development in
flood prone areas
Operational Adjustments & Capacity Building
• Created a System Operations and Planning Analysis (SOPA) Group• Tailors National Weather Service info to SPU drainage needs
• Projects possible system impacts
• Anticipates call volume
• Analyzing characteristics of historic “storms of concern”
• Created Storm Observer Program• Staff deployed to know problem areas ahead of storm
• Boots on the ground to identify potential problems
• Improvements to Operations Control Center
• Regional Communications
• Customer Service Program
• Incorporating new skills
Applied Research: Nowcasting
• Nowcasting:
• Spatially refined precip
forecasting tool
• Integrates rain gage data
with radar
• Urban drainage scale
• 60‐90 minute forecast,
increase to 3 hrs. with
coastal radar
Applied Research: Sea Level Rise
• Created GIS layers
• Produced inventory of assets
inundated
• Moving towards system impacts
• Incorporate into asset
management framework
Scenario Estimate by Year
2050 2100Low n/a 6”
Medium 6” 13”High 22” 50”
Extreme 60” 88”
Experiment: Dynamical Downscaling
• Used downscaled data from UW
CIG State Assessment
• Ran data through urban
drainage hydrology model
• Not of much utility at this point
Green Stormwater
Infrastructure
• Integrating into Capital and
O&M Programs• Initial focus was reducing
runoff impacts in creek basins
• Analyzed cost/performance of
parcel and ROW based
strategies
• Used that analysis in CSO
control planning
• Rainwise
program –
https://rainwise.seattle.gov/sys
tems/water
• Incorporation into Code• New development must use
GSI to maximum extent
feasible
Collaboration
• Water Environment Research Foundation
Issue Area Team
• EU Research Projects
– MARE
– Prepared• Urban Drainage Adaptation Workshop
• PUMA
• Opportunities to:
– Address information gaps
– enhance knowledge– learn from others
Conclusions and Observations
• Primary area of interest is precip
and changes in hydrology
• Projected increases in extreme events, but projections are uncertain
• Use bottom up, “no regrets”
approach
• Pursue adaptation in multiple realms– Opportunities to leverage broader societal adaptation
• Consider capacity building, institutional development and
collaboration as forms of adaptation• Move towards incorporating climate info into decision‐
making (e.g. CIP)
Thank You
“Stimulate…intensive,multi-disciplinary cooperation”