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The EPA's most recent water quality criteria (EPA, 1975) recommend that fecal coli forms be used as the standard for evaluating the sanitary quality oT water. The State's proposed draft standards would follow this 'recommendati on and drop the current standards for t.ota 1 coli forms and fecal streptococci. On the basis of the .draft standards, the reservoir could be classified as being suitable for primary contact recreation. . Temperature Simulation Using the Corps of Engineers (1973) modification of the Water. Resources Engineers (WRE) Reservoir Temperature Simulation Moejel, the temperature regime of the reservoir was simulated. The simulation was run for three years, compriSing 1963, 1955, and 1957; these represent a "dry," a "wet," and a typical year respectively on the basis of total animal runoff. Input data were drawn from the National Weather Service Climatological Data Record, the Geological Survey stream gaging network, and the Bureau's Operations Study for the Narrows Unit. The streamflow data were taken from the records at the Weldona gaging station, while the daily inflow temperatures for the Julesburg Irrigation Network Station were used. The Jul espurg data were used only after a statistical comparison with all available data for the Weldona station verified the validity of superimPosing them upstream. The results of the simulation indicate that the reservoir will usually follow the classic spring pattern Of surface warming and have a period of the estapl ishment and disr\lption of near-surface, unstable strati- fication. This period would last for one to two months. The duration of stratification and the maximum summel" temperature were ultimately dependent on the size of the reservoir pool at initial spring warming.A1though1955 was a "wet" year on the basis of runoff, prior to the onset of the spring runoff, thereservoirwa.s at its lowest level of the three years, i.e. approximately 14 meters deep. Under this condition, the above described pattern occurred during the spring. This was followed by a rapid warming to the bottom and no development of persistent stratification. During June, extreme inflow raised the pool level by six meters. However, no ~Iell- defined stratification developed, and the reservoir cDntinued warming throughout the summer. The bottom temperature was in excess of 200 C for a period of 50 consecutive days. 19 .',' "-. 'i: