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• Environmental Permitting. Infarmation on major `roadblocks' in the NEPA and Army Corps of <br />Engineers 404 permitting process will be identified where practicable and applicable. <br />Task 3 — Site Reconnaissance <br />Site reconnaissance will consist of one site visit to the area of study described in the document by up to two <br />Boyle/AECOM personnel for up to 2 days. To the extent possible, the site visit will include the potential <br />reservoir site described in the report, two potential diversion locations, and possibly portions of the potential <br />conveyance alignrnents identified under Task 2. <br />The site visit will be performed to observe the proposed dam location and surficial geologic features. It is <br />assumed that there are no site access restrictions with respect to accessing the potential dam and reservoir site <br />identified in the report and any required permissions will be the responsibility of CWCB. <br />Task 4 — Analysis <br />The analyses below will be based on information gathered under Task 2 and Task 3: <br />• Conveyance Feasibility. Both the gravity-fed and the pumped conveyance systems to the reservoir will <br />be assessed for feasibility. The gravity fed conveyance is estimated to have a relatively flat slope over it's <br />entire length. The soils, geology, conveyance losses, and land use for the gravity conveyance system will <br />be evaluated. Conveyance losses will be assessed by urilizing available infiltration and evaporation data. <br />The pumped system will be evaluated for conveyance costs. <br />• Project Demand. Water demand will be analyzed based on the information available of the potential end <br />users, and recreation. This will be performed at a qualitative level to determine whether a need exists <br />based pn the information obtained under Task 2. <br />• Reservoir Yield. The reservoir yield will be assessed based on potential viable water ri�hts, hydrology, <br />water demand, and conveyance losses. Reservoir yield will be analyzed for up to three scenarios based <br />on these factors. <br />• Water Quality. Water quality data wiil be qualitatively analyzed based on the available data. <br />. Dam Type/Layout. The dam type and layout will be selected based on the geologic conditions at the site. <br />Up to two dam layouts will be developed. Foundation considerations will include the conceptual analysis <br />of its strength and seepage properties and resulting surface preparation, grouting, and key/core trench <br />requirements. <br />• Spillway Layout and Sizing. For the purposes of this study, the dam will be considered to be high-hazard, <br />and therefore spillway sizing will be based on hydrologic analysis for the local and general pzobable <br />ma�cimum precipitation (PMP) flood events. These events will be analyzed using the relevant HIVIR data <br />andlor the State Engineer's Office's (SEO) Extreme Precipitation Analysis Tool (EPAT). The conceptual <br />spillvcray layout will based on geologic and foundation information from the recannaissance survey. <br />Spillway hydraulic analysis will include typical spillway components including alternative crest design, <br />discharge chute, and energy dissipating structure. A spillway rating curve will be developed ta support <br />interactive assessment of reservoir uolume, dam height, and freeboard requirements. One spillway <br />alignment will be developed. <br />• Outlet Works Sizing. A reservoir evacuation calculation will be performed according to SEO guidelines <br />to estimate the outlet pipe diameter. <br />BOYLE � �t��'��� <br />Grand Valley_Dam_Scape_3-9-09.doc - 3/16/2009 - 3 - <br />