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... !' ~j ~ ~\J 11 The initial pool level for the 1963 simulation was slightly greater than the 1967 initial pool level. During both years the above described spring pattern occurred. During the summer of both years, near surface stratification developed. However, there was no extensive deepening of the thermocline as is usually the case in temperate lakes and reservoirs. The thermocline that developed was never below 2.5 meters in either year and was at about one meter deep for most of the time that defined stratification was present. In addition to the thermocline being near the surface, it never thickened appreciably. The thermocline was usually one to two meters thick, but extended for four meters for one week duri ng 1967 and three meters for a week duri ng 1963. On the whole, the reservoir did not exhibit stable stratification during either year. In both cases there was warm water inflow to the surface throughout the summer. Despite the surface inflow the bottom waters were warmed continually and rather extensively during both years. This would indicate a 'surface exchange across the thermocline as well as the influence of longwave radiation. Since the thermocline remained relatively shallow, the hypolimnion was quite extensive and comprised the greater part of the reservoir volume. In addition, the bottom withdrawals extended to the floor of the reservoir, such that there was no indication of a "dead zone" in the area deeper than the outlet works. On the basis of the extent of the hypolimnion, and consequently the large dissolved oxygen reservoir, along with the evident surface exchange, which was probably due to a combination of inflow-outflow rel ationshi ps and diffusion, it was concluded that the bottom waters should remain aerobic during the summer. The South Platte River carries a large salt load throughout most of the year. Due to this, it was felt that there was a possibility that the salinity could create density differences in excess of those resulting from temperature. In such a case, chemical stratification could develop and inhibit the above described exchange. However, the results of the analysis indicated that the differences in salinity between the inflowing water and the reservoir pool would be insufficient to overcome the density differences resulting from purely thermodynamic processes as descri bed above. Therefore, there woul d be 1 i ttl e 1 i kel i hood of any chemical stratification occurring. 20