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Cooperative Project where the District works with multiple stakeholders in the State,primarily the <br /> Colorado Water Conservation Board and the Colorado Division of Parks and Wildlife to restore the full <br /> use of the reservoir. The project is made up of final design,program/project management and three <br /> primary construction components that address structural and/or operational deficiencies of the Reservoir, <br /> as described below: <br /> Final Design <br /> The rehabilitation of Rio Grande Reservoir requires that the proposed improvements be designed, <br /> managed,and inspected by a professional registered engineer in the State of Colorado. The engineering <br /> firm selected to conduct this work will provide overall project management, surveying, geotechnical <br /> exploration,geotechnical and hydraulic analysis,and the final design of the spillway,clay blanket liner, <br /> bypass tunnel and outlet works. The engineering firm will also provide cost estimating,QA/QC for the <br /> project, respond to State Engineer comments and assist will bidding and award for the project. This work <br /> is currently being conducted by SLVID under Contract C154210 at a cost of$1,256,134, under its sub- <br /> consultant—Deer and Ault Consultants. <br /> Program/Project Management <br /> The Rio Grande Cooperative Project involves the coordination and management of many different project <br /> components. Some of key project management issues that need to be addressed prior to the SLVID <br /> proceeding forward with construction,are 1)successful negotiation,feasibility analysis and exchange of <br /> land between the Forest Service and the SLVID,2)storage accounts and operation modeling,3) <br /> execution of storage agreements,and 4)overall stakeholder coordination and program management. The <br /> successful management of these key issues is vital to the overall success of the Project. <br /> Primary Construction Components <br /> 1.)Upstream Clay Blanket-In order to reduce seepage through the rock slide formation at the left dam <br /> abutment,a clay blanket slope liner will be installed on the upstream side of the dam at the left abutment. <br /> The clay blanket,shown on Figure 1 in plan and Figure 2 in cross-section,will be a zoned fill placed <br /> over the rock slide and extending across the west abutment of the dam approximately 100 feet. The zones <br /> include a filter layer, low permeability clay core,and cover zone.This improvement is expected to <br /> substantially reduce seepage and allow full storage capability of the reservoir to be achieved. Clay liner <br /> materials will be obtained by borrowing and processing approximately 20,000 cubic yards of soil and <br /> rock material from reservoir property.These areas are described in Figure 1. Processing shall consist of <br /> screening various gradations from the existing landslide deposit,as described in Exhibit 1. The clay liner <br /> material for the construction component described above is currently being conducted under Contract <br /> C154213,under its sub-consultant—Brad Moore,at a cost of$295,699.66. <br /> 2.)Low Level Outlet-The existing low level outlet will be replaced with a hollow jet valve discharge <br /> structure at the downstream side of the dam. The existing low level outlet tunnel will continue to be used <br /> to provide conveyance between the upstream and downstream portals.The existing sluice gate control <br /> structure will either be demolished or abandoned in-place with a bypass tunnel providing conveyance <br /> around the structure;this is shown on Figure 1. Schedule constraints for the work and the uncertainty of <br /> the demolition costs(for removal of existing sluice gate control structure)suggest that the construction <br /> bidding process may be the best way to determine the most economic solution.To that end,we <br /> recommend preparing the bidding documents with two options: Option 1 —Demolish Existing Sluice <br /> Gate Structure and Option 2—Construct Bypass Tunnel and Abandon Sluice Gate Structure.The District <br /> can then select which option is most economic based on the results of the bidding.Another important <br /> element of the low level outlet works is the provision for the future addition of hydropower.To allow <br /> hydropower to be added in the future with minimal disturbance to the primary function of the project,a <br /> tap will be provided at the low level outlet(downstream of the tunnel portal)which can be used to route <br /> flows to future turbine generator units. <br /> 2 <br />