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EXHIBIT A <br /> Statement of Work <br /> Page 1 of 4 <br /> BACKGROUND <br /> The San Luis Valley Irrigation District (SLVID) owns and operates the Rio Grande Dam and Reservoir on <br /> the Rio Grande in southwest Colorado.The dam is a 111-foot high earth and rock fill embankment with <br /> a crest elevation of 9470 feet. Key features of the project include the dam with a crest length of <br /> approximately 450 feet, an un-gated spillway at the right abutment of the dam, and a low level outlet <br /> that includes an 11-foot high by 15-foot wide tunnel with a multiple sluice gate control structure near <br /> the middle of the tunnel.The reservoir is approximately six miles in length and 0.50 miles in width, <br /> oriented in a roughly northwest-southeast direction and has a capacity of 52,192 acre-feet. <br /> A comprehensive study for rehabilitation and/or enlargement of the dam and reservoir was conducted <br /> by Deer and Ault Consultants (D&A) and Camp Dresser& McGee (CDM) in 2007 and 2008 ("Rio Grande <br /> Multi-Use Rehabilitation and Enlargement Study,"CDM, 2008).That study estimated costs of$19.2 <br /> million for rehabilitation and $33.2 million for enlargement. <br /> Construction of the dam began around 1908 with completion in 1914. The dam was constructed in a <br /> narrow valley between a massive volcanic formation known as Fish Canyon Tuff(at the right abutment) <br /> and a large rock slide that is a mixture of clays, sands,gravels, and large blocks of tuff(at the left <br /> abutment).The highly permeable rock slide material at the left abutment has been problematic since <br /> the first filling of the reservoir where seepage of the order of 1,500 gpm has been measured in the left <br /> abutment, with a total combined seepage of 2,500 gpm downstream of the dam.The seepage flow is <br /> responsive to reservoir elevation with flows increasing significantly at higher reservoir elevations (at <br /> gage 60 and above). <br /> The low level outlet was originally constructed with 10 sluice gates, made up of five control gates and <br /> five upstream guard gates.The gates frames used a combination of concrete and steel framing to <br /> support the gates. When first operated, the gate structure experienced significant vibrations such that <br /> failure of the gates appeared likely.The response was to fill two of the three gate chambers with <br /> concrete and extend the concrete downstream of the gates for a length of 5 feet to create a more rigid <br /> structure.This initial repair was completed in 1915 and was apparently left unchanged until 1982. <br /> Between 1982 and 1999, a series of repairs were made to the control gates, including replacing the <br /> three active gates and reinforcing the framing around the gates.After the last repairs were made in <br /> 1999,the flows from the low level outlet have been restricted to approximately 1,200 cfs;flows <br /> significantly greater than 1,200 cfs cause excessive vibrations in the gates, gate stems, and steel <br /> reinforcing downstream of the gates. <br /> The dam was originally constructed with an unlined spillway at the right abutment.The spillway has <br /> been modified since its original construction by lengthening the crest of the spillway and lining the <br /> spillway deck and walls with concrete. A recent analysis on the spillway, performed by CDM in 2008, <br /> suggests that the spillway training walls are insufficient in height to pass the required 6,600 cfs design <br /> flow.The training wall height deficiencies exist at the entrance of the structure and continue throughout <br /> its length.The greatest concern with the spillway training wall heights exists on the left side. Any <br />