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Climate Change and Sustainable Water Infrastructure: King County. David Monthie King County DNRP January 2008 2008 Symposium on Innovating for Sustainable Results. Presentation Objectives . Adaptation Basics: Guidebook, King County Climate Plan
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Climate Change and Sustainable Water Infrastructure: King County David Monthie King County DNRP January 2008 2008 Symposium on Innovating for Sustainable Results
Presentation Objectives • Adaptation Basics: Guidebook, King County Climate Plan • Recent successes in Water Supply, Flood Management • Developing Wastewater Strategy • Final thoughts and suggestions
Some Facts about King County • 2,134 Square Miles • 1.8 Million residents (14th largest county in U.S.) • 39 Cities • Farmland and the Cascade Mountains on the east side, Puget Sound and urban coastline on the west side • Three listed fish species under ESA (chinook salmon, bull trout, steelhead) • County govt provides local services and regional services include: regional transit, sewage treatment, solid waste disposal, flood control, regional parks, public health
Major Water Utilities • Water supplied by three major utilities—Seattle (70%), Tacoma, Everett—all with surface supply sources from Cascades • Regional wastewater system operated by King County; 30+ local collection systems • Countywide flood management district operated by King County (as of 2007) • Stormwater utilities operated by local govts, incl King County in unincorporated
Insight from a Notable American Philosopher “The future ain't what it used to be.” -- Yogi Berra
Local Evidence of Climate Change on Water (UW CIG) • Declining snowpack • Shifts in timing of runoff • Declining trend on overall runoff volume
What We Forecast • Higher temps by 2100; PNW temp increases more than global avg now, up roughly 1.8 degrees F every 25 years • Total precip may go up; more rain than snow; storm intensity likely to increase • PNW snowpack will decline; runoff earlier • Increased risk of floods and drought • Rises in sea level: levels speculative • Unclear impacts to groundwater
King County Actions • Creation of formal Global Warming Team w/in Executive’s office • Executive orders: lower carbon emissions, greater use of advanced technology, new energy policies and the increased use of biodiesel • Comprehensive strategy addressing both mitgation and adaptation(2007 Climate Plan) • Take home: leadership at the top makes a big difference
2007 King County Climate Plan • Includes both Mitigation and Adaptation • 170 pp—across all sectors of County activities • Includes goals, activities, milestones, measures • Includes KC work and collaborations • Annual report/update
Climate Change Guidebook • Preparing for Climate Change: A Guidebook for Local, Regional and State Governments • Developed with UW and ICLEI • Builds on KC experiences
Climate Change Guidebook--Approach • ID relevant areas • Vulnerability Assessment • Risk Assessment • Adaptation Strategy • Implement • Measure
Relevant Areas—Water (identified in 2007 Climate Plan) • Water supplies: threats from declining snowpack, reduced flows, higher temps, increasing demands • Flooding: threats from higher flows, more intense events, aging infrastructure, development • Wastewater: threats from rising sea levels, intense storms, existing capacity issues
Water supplies: Vulnerability and Risk Assessment • Convened regional water planning process in 2005 • Includes major water utilities, local govts, enviros, tribes, others • Work revolving around 7 technical committees by substantive topic; geographic scope varied • Climate Change Committee w/UW CIG as tech lead, three-county geographic scope
Climate Change Building Blocks • Peer-reviewed literature • What is known and widely accepted about climate change
Downscaled Global Models • 3 GCM’s w/2 GHG scenarios • Downscaled to apply to King County watersheds • Meteorology entered into hydro models • Streamflow forecasts to 2075
2000 2026 2050 2075
2000 2026 2050 2075
Water Utility Risk Assessment and Adaptation • Water utilities (Seattle, Tacoma, Everett) used streamflow data as input to system models (vs. historic meteorology/hydrology) • Key impacts are changes in timing of flows • Utility forecasted impacts on firm yield by 2075 of -3% to -18% annually, possibly more • Allows for planning; mitigation steps already being identified by utilities • Unaddressed issues, e.g.,multiyear drought, storms
Flood and Stormwater Management • KC has six major rivers, and more than 115 miles of riverbank • Floods are controlled to some extent by an aging system of 500 levees/revetments • FEMA-driven flood plain management is based on old maps (remember Yogi!) • New mapping underway in WA—proposed floodplain boundaries creating concerns for residents
Vulnerability and Risk Assessment for Flood and Stormwater Systems • Low-lying developed areas could be flooded—could include Boeing Renton plant, Southcenter major shopping area • Econ study: one event could generate $42 million harm • Physical risk: many levees built of soft sand—susceptible to repeat events • Scour in streambeds and stormwater channels—loss of functions and habitat, impact on ESA recovery plans • Warming could result in changes to vegetation that helps in managing high precipitation events • Management issues: multiple flood districts, competing interests with water suppliers
Adaptation and Planning Response • New Countywide Flood Hazard Management Plan • $179 million in projects over 10 years—including levee fixes, acquisition of flooding properties, expanded Warning Center, restrictions on development in floodplains • Creation of countywide flood control district (consolidate existing districts) • Approval of regional funding source (property tax) • New stormwater manual—emphasizes processes to mimic natural hydrology • Active efforts to preserve forest and natural lands • Low impact development emphasis in land use, esp critical and vulnerable areas—new Shoreline plan
King County’s Wastewater Service Area • 34 Local Agencies • Two Regional Treatment Plants • Serves 1.4 million • Service Area: 414 square miles • Combined: 70 square miles • King County Sewers: 335 miles • Local Agency Separated Sewer: 3,300 miles
Regional Wastewater System Basics • System designed and constructed based on historic data (including rainfall)—capacity based on historic peak flows (remember Yogi!) • Effects on planning/operation related to both combined and separated sewers • Location of combined sewer outfalls (CSO’s) determined by highest observed tides • I&I drives capital costs—75% peak flows in separated system, 90% in combined • Recl water not built into planning—until now
Wastewater System Vulnerability and Risks • Increased rainfall/intense events raise questions of cost to construct capacity, and whether the system will be overwhelmed • New high tides could back up CSO’s, cause saltwater damage to system • Major investment decisions: 2006 capital budget for combined system is $780 million through 2050; $400 million for separated; budget is rising (adopted 2008 five-year capital budget is $1.938 billion)
Risk: CSOs Influenced by Tide Combined Sewer Outfalls (CSOs) Influenced By Tide • Elevation of CSO Outfalls Determined by Highest Observed Tide
King County 2007 Climate Plan 2. To support operational resilience of wastewater treatment facilities • Collaborate with climate science experts to develop reasonable regional assumptions for long-range planning purposes • Develop a reclaimed water comprehensive plan for regional production, distribution and application to support natural water systems • Develop strategies to manage wet weather impacts of climate change to the sewer system
Wastewater: King County 2007 Climate Plan • Collaborate with climate science experts to develop reasonable regional assumptions for long-range planning purposes • Obtain more detailed local and regional climate information upon which to base planning assumptions • Provide consistency between multiple agencies and departments • Further understanding of future impacts and costs across agencies and departments
Wastewater Adaptation: Identify Vulnerable Facilities • Goal - Identify WTD facilities impacted by storm surge/sea level rise (above extreme high water), and intense storm/urban flows, and the impact on each facility • GIS based analysis: to be completed in 2008 • Identify the impact threshold (consultant) • Identify the level of impact (consultant)
Wastewater Adaptation: ID Potential Strategies • Develop response strategies • Identify adaptive strategies for each facility (i.e., berm, armoring, relocation, etc.) • Identify operational strategies (facility specific and system-wide) • Develop cost estimates and schedules
Wastewater: Develop Adaptation Plan • Update and integrate capital and asset management plans accordingly • Select strategies • Revise capital and asset management plans (e.g., capital investment thresholds; asset replacement schedules) • Revise operational protocols • Complete asap—2009 (?)
Storm Intensity • Difficult to predict w/climate models; area-specific • Significant issues for urban stormwater • November 2006: 5” precip in 24 hours->one death, $millions in claims in Seattle • November 2007: 4” precip in 24 hours (second highest in 50 years)->different areas of Seattle flooding • I-5 shutdown 4 days below Olympia
WTD System Performance and Vulnerability • System performed well given size of the storm and the amount of urban flooding • Treatment plants ran at or over capacity during the entire storm, did not have any major failures or damage • Problems w/pumps handling volume of treated water • Urban flooding/I&I overwhelmed some facilities—flows to streams, beaches
December 2007 storm: Summary • Plants and whole system ran at or over its capacity • Need to work with local jurisdictions on urban flooding impacting our system • Need to work on infiltration/inflow (I/I) • Need additional capacity (third treatment plant—Brightwater) • Need long-term climate strategy
Water Resource and Management Challenges • Evolving science: will require dynamic planning and decision making • Investment risks: what are appropriate thresholds, who bears the risk • New approaches: e.g., decentralization and flexibility in order to increase resilience; integration (reclaimed water as resource) • Inadequate management structures and institutions: competing interests (flood management vs. water supply), regional approaches • Costs: will likely be high
Suggestions for national support • Encourage or require states to incorporate climate change into appropriate planning • Condition financial assistance funding (e.g., SRF) on accounting for climate change in utility infrastructure planning • Provide direct technical assistance or financial support (e.g., downscaling) • Provide a one-stop clearinghouse for all categories of climate change information
More resources • Climate Change Tech Comm report (UW CIG): www.cses.washington.edu/cig/fpt/planning • KC global warming: http://www.metrokc.gov/global warming • KC flood hazard management plan: http://www.metrokc.gov/wlr/flood/FHMP • International Council for Local Environmental Initiatives (Guidebook): http://www.iclei.org/ and UW CIG (see above) • KC regional water planning: www.govlink.org/regional-water-planning