New efforts in planning for large scale ecosystem restoration in the Sacramen...
Status of Capitol Lake Planning in Washington State
1. The Status of Capitol Lake Planning Washington State Capitol CommitteeOctober 12, 2010
2. CAPITOL LAKE Setting the Context 1856: U.S. Coast SurveyDepartment of the Navy1911: State Capitol CommissionHires Olmsted Brothers and Wilder and White.1912: Olmsteds write to Gov. Hay suggesting improvements to the inner harbor which “may be accomplished from time to time as opportunity arises”.
3. CAPITOL LAKESetting the Context 1927: Correspondence from Wilder & White to the Capitol Committee: “Improvement of the water front…has been given very little study on the Olmsted Plan and we believe it would be unfortunate to leave it at this stage.” Wilder & White - undated 1937: The Legislature appropriated $150,000 to create Capitol Lake. The “Des Chutes Water Basin” project would acquire land, construct a parkway, and dam the river. The affected area would become part of the capitol campus. 3
4. CAPITOL LAKESetting the Context 1951: Project completed. Since 1951 more than 2,000,000 cubic yards have accumulated in the basin. Maintenance dredges have not removed sediment, but simply changed the lake’s shape. 1995: GA prepared proposal for a maintenance dredge. 1997: Dredge proposal withdrawn and CLAMP Committee formed to advise GA on management of the basin. TRPC
36. Technical Considerations Managed Lake Little change in infrastructure. The operation of the dam provides greater protection against the initial effects of sea-level rise on downtown flood risk. A large initial dredge is required in addition to regular maintenance dredging. Dredging inside the lake is more difficult than in Budd Inlet. Estuary Initial and maintenance dredging are lessened; most sediment is moved to the shoreline, reducing costs and permitting complexity. Significant infrastructure is required early in implementation (including building a new 5th Avenue bridge and reinforcement of Deschutes Parkway) Dual Basin Estuary In addition to estuary alternative considerations, constructing a north basin barrier involves engineering and environmental uncertainties.
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41. PSNERP was initiated in 2001 to identify nearshore ecosystem problems and solutions.
42. PSNERP process may result in significant federal funding for projects to restore Puget Sound.
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Notes de l'éditeur
Basin management discussions remain highly polarized between lake and estuary advocates. A constituent group, the Capitol Lake Improvement and Protection Association (CLIPA), issued a report at the end of June 2010 critiquing the CLAMP analyses and providing further support for lake management. Another constituent group, the Deschutes Estuary Restoration Team, has also formed, to support the estuary recommendation.
Managed LakePros: Little change in infrastructure is required. The operation of the dam provides greater protection against the initial effects of sea-level rise on downtown flood risk.Cons: A large initial dredge is required in addition to regular maintenance dredging. Dredging inside the lake is more difficult than in Budd Inlet.EstuaryPros: Initial and maintenance dredging are lessened; most sediment is moved to the shoreline, reducing costs and permitting complexity. May improve transportation flow.Cons: Significant infrastructure changes are required early in implementation (including building a new 5th Avenue bridge and reinforcement of Deschutes Parkway).Dual Basin EstuaryPros: Same as estuary alternative.Cons: In addition to estuary alternative considerations, constructing a north basin barrier involves considerable engineering uncertainties and may not provide an environmentally self-sustaining system.Remaining Technical Uncertainties:Limited Options – CLAMP’s process focused on the lake/estuary options.
Costs for any of the studied options are projected to exceed $100 million over 50 years and may be much higher, depending on assumptions. Further, CLAMP’s process did not analyze effects on the local economy. Creation of the lake established a significant economic benefit to downstream marine interests by reducing sedimentation in lower Budd Inlet. [EXPAND/CLIPA]Managed LakePros: Relatively little cost required for infrastructure. Preserves significant cost benefits to downstream marine economic interests. Cons: Greater initial dredge is required, in addition to greater regular maintenance dredging. EstuaryPros: Initial dredging and maintenance dredging quantities and unit costs are lower. Cons: Significant infrastructure renewal is required early in implementation.Dual Basin EstuaryPros: Same as estuary.Cons: Same as estuary, except for added costs and impacts of north basin barrier work.Remaining Economic Uncertainties:Dredge Costs – Dredging is necessary in any option and is the largest cost element. The presence of invasive New Zealand mudsnails will likely increase disposal costs. Downstream economic impacts – Economic impacts to the local economy from changes in lake management have not been evaluated. [EXPAND/CLIPA]Construction in estuary scenarios will likely impact downtown economic activity (similar to Fourth Avenue Bridge project).
Portions of the Deschutes River, Capitol Lake, and Budd Inlet do not meet federal water quality standards and are on the Clean Water Act Section 303(d) list for one or more of the following parameters: fecal coliform bacteria, temperature, dissolved oxygen, pH, or fine sediment. Budd Inlet suffers from very low dissolved oxygen levels. Improved flushing in the Inlet and the associated reduction in dissolved oxygen concerns is cited by some parties as the most compelling argument for estuary restoration. Ecology estimates that estuary restoration may resolve dissolved oxygen concerns for about one-half of the affected area in the Inlet (~650 acres resolved). Most other water quality issues originate in the watershed above the lake basin, which is a concern since changed lake management strategies will have no effect on upland inputs.[EXPAND/CLIPA/NZMS]Managed LakePros: Supports insects that are an important food source for foraging birds and bats.Cons: Would continue to support several invasive and non-native species, including exotic amphibians and mammals. Dam increases risk of predation for migrating salmon. Is expected to make efforts to improve water quality in Budd Inlet more difficult.Estuary or Dual Basin EstuaryPros: Increased tidal flushing is expected to improve water quality in the basin and Budd Inlet. Would improve habitat for anadromous and marine fish. Would restore 260 acres of an ecosystem type that has been significantly reduced throughout Puget Sound.Cons: Loss of nearly all habitat used by freshwater species. Reduced forage insects for bats and some birds. Potential for all 16 lake-dependent freshwater fish to be eliminated.Remaining Environmental Uncertainties:Total Maximum Daily Load (TMDL) Planning – Ecology’s ongoing water quality study required under the federal Clean Water Act will deliver a Deschutes watershed cleanup plan, and the lake management decision may affect, and be affected by, the TMDL process.Puget Sound Near-Shore Restoration Projects – For several years, theUSDFW and the US Army Corps of Engineers have been identifying and evaluating potential projects for near shore restoration. Deschutes Estuary restoration has been identified as one of 47 candidate projects for their consideration.
(Joyce)The 2010 Legislature ended CLAMP committee funding. The CLAMP process identified some critical shared interests and objectives among all members. However, lake and estuary advocates remain polarized, and disputes persist over the CLAMP analyses and conclusions. The State Capitol Committee and Legislature still must act before any long-term management can begin. Permitting for such a strategy is projected to take four to six years and involve more than 20 different federal, state, local, and tribal authorities. As a result of these factors, the permanence of any decision and the ongoing care of the basin have become major considerations. While these deliberations are continuing, GA has also submitted a capital project request to begin the process for seeking a permit to conduct a limited dredge of Capitol Lake for flood risk mitigation purposes. Permitting is expected to take 4-5 years. Such a dredge will not constrain consideration of any of the long-term management strategies currently under evaluation.