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Climate Change and Sustainable Water Infrastructure: King County

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

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  1. Climate Change and Sustainable Water Infrastructure: King County David Monthie King County DNRP January 2008 2008 Symposium on Innovating for Sustainable Results

  2. Presentation Objectives • Adaptation Basics: Guidebook, King County Climate Plan • Recent successes in Water Supply, Flood Management • Developing Wastewater Strategy • Final thoughts and suggestions

  3. King County looks like this….

  4. And this….

  5. And this.

  6. 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

  7. 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

  8. Insight from a Notable American Philosopher “The future ain't what it used to be.” -- Yogi Berra

  9. Local Evidence of Climate Change on Water (UW CIG) • Declining snowpack • Shifts in timing of runoff • Declining trend on overall runoff volume

  10. 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

  11. 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

  12. 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

  13. Climate Change Guidebook • Preparing for Climate Change: A Guidebook for Local, Regional and State Governments • Developed with UW and ICLEI • Builds on KC experiences

  14. Climate Change Guidebook--Approach • ID relevant areas • Vulnerability Assessment • Risk Assessment • Adaptation Strategy • Implement • Measure

  15. 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

  16. 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

  17. Climate Change Building Blocks • Peer-reviewed literature • What is known and widely accepted about climate change

  18. 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

  19. 2000 2026 2050 2075

  20. 2000 2026 2050 2075

  21. Projected Changes in Spring Flows 2000 to 2075

  22. Projected Changes in Summer Flows 2000 to 2075

  23. Projected Changes in Winter Flows 2000 to 2075

  24. 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

  25. 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

  26. 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

  27. 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

  28. 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

  29. 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

  30. 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)

  31. Risk: CSOs Influenced by Tide Combined Sewer Outfalls (CSOs) Influenced By Tide • Elevation of CSO Outfalls Determined by Highest Observed Tide

  32. 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

  33. 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

  34. 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)

  35. 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

  36. 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 (?)

  37. 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

  38. 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

  39. Carkeek CSO Treatment Plant – Grit Tank

  40. Carkeek CSO Treatment Plant – Sedimentation Tank

  41. 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

  42. 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

  43. 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

  44. 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

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