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I I I I I I I I I I I I I I I I I I I area, occas i ona 1 small 1 oca 1 i zed seeps are observed when the reservoi r is at its full normal pool elevation. Control and drainage of these minor seepage areas coul d be accompl i shed by extendi ng the toe drai n further towards the right abutment. Seepage which occurs through the overflow auxiliary spillway dikes on each side of the concrete ogee service spillway is of greater concern than seepage at the dam. In 1984, materi al s were removed from the upstream face of the dikes and used at the downstream toe of the dam for fill. The crest of these dikes was also lowered one foot. This resulted in a substantial shortening of the seepage path through the dikes with the reservoir at normal pool elevation 9087 (G.H. 40). At this level, uncontrolled seepage was observed at several locations on each side of the concrete service spillway and along the right spillway/dike contact. The seepage was stopped when the reservoir was lowered to elevation 9085 (G.H. 38). The City has established elevation 9083 (G.H. 36) as a self-imposed reservoir restriction to prevent seepage from occurring at these locations. Because of the erosive nature of the granular material comprising the overflow dikes, sustained seepage at these locations could lead to piping and failure of the dike embankments. Therefore, the City's self-imposed reservoir restriction at G.H. 36 is warranted. 2.6 Recommended Interim Operating Restriction Based on the sel f-imposed maintained. si te i nspecti on, it is recommended that the Ci ty I S current reservoir restriction to elevation 9083 (of G.H. 36) be 3.0 HYDROLOGY AND HYDRAULICS 3.1 Probable Maximum Flood The drainage basin for Barnes Meadow Reservoir 1 ies north of Rocky Mountain National Park in the Roosevelt National Forest as shown on Figure V.6 in Section 5 of this chapter. The basin divide is located at approximately 1231 H -61-