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Exhibit A <br /> Statement of Work <br /> Rio Grande Cooperative Project <br /> November 30,2012 <br /> BACKGROUND <br /> The San Luis Valley Irrigation District(SLVID) owns and operates the Rio Grande Dam and <br /> Reservoir on the Rio Grande in southwest Colorado.The dam is a 111-foot high earth and rock fill <br /> embankment with a crest elevation of 9470 feet.Key features of the project include the dam with a <br /> crest length of approximately 450 feet,an un-gated spillway at the right abutment of the dam,and a <br /> low level outlet that includes an 11-foot high by 15-foot wide tunnel with a multiple sluice gate <br /> control structure near the middle of the tunnel.The reservoir is approximately six miles in length <br /> and 0.50 miles in width,oriented in a roughly northwest-southeast direction and has a capacity of <br /> 52,192 acre-feet. <br /> A comprehensive study for rehabilitation and/or enlargement of the dam and reservoir was <br /> conducted by D&A and CDM in 2007 and 2008("Rio Grande Multi-Use Rehabilitation and <br /> Enlargement Study,"CDM,2008).That study estimated costs of$19.2 million for rehabilitation and <br /> $33.2 million for enlargement. In addition,the District has previously conducted studies regarding <br /> operations of Rio Grande Reservoir. The Rio Grande Reservoir Multi-Use Project Studies <br /> (collectively"Multi-Use Studies") identified basin-wide benefits from the use of storage and re- <br /> operations of Rio Grande Reservoir.These studies also concluded that CPW can particularly benefit <br /> from storage in Rio Grande Reservoir as it relies upon storage to manage some of its water <br /> resources. In recent years,under a non-permanent lease agreement,CPW,the San Luis Valley <br /> Water Conservancy District and others have stored up to 10,000 AF of water in Rio Grande <br /> Reservoir. In addition,the benefits of compact storage for Rio Grande Compact compliance and <br /> basin administration were outlined. The Multi-Use Studies revealed that Rio Grande Reservoir <br /> must be rehabilitated in order to provide long-term regulation of CPW water rights and other basin <br /> water supplies as well as storage for compact compliance. <br /> Construction of the dam began around 1908 with completion in 1914.The dam was constructed in <br /> a narrow valley between a massive volcanic formation known as Fish Canyon Tuff(at the right <br /> abutment)and a large rock slide that is a mixture of clays,sands,gravels,and large blocks of tuff(at <br /> the left abutment).The highly permeable rock slide material at the left abutment has been <br /> problematic since the first filling of the reservoir where seepage of the order of 1,500 gpm has been <br /> measured in the left abutment,with a total combined seepage of 2,500 gpm downstream of the <br /> dam.The seepage flow is responsive to reservoir elevation with flows increasing significantly at <br /> higher reservoir elevations (at gage 60 and above). <br /> The dam was originally constructed with an unlined spillway at the right abutment.The spillway <br /> has been modified since its original construction by lengthening the crest of the spillway and lining <br /> the spillway deck and walls with concrete.A recent analysis on the spillway,performed by CDM in <br /> 2008,suggests that the spillway training walls are insufficient in height to pass the required 6,600 <br /> cfs design flow.The training wall height deficiencies exist at the entrance of the structure and <br /> continue throughout its length.The greatest concern with the spillway training wall heights exists <br /> on the left side.Any overflow of the left training walls has the potential to threaten the right <br /> abutment of the main dam.Based on the 2008 study,this appears at flows below the design flow of <br /> 6,600 cfs. <br />