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o <1<13 foundation of the dam? Our assignment deals only with the second question. It is known that the deep aquiIer has its basic source of recharge from the bed of the South Platte River, along the reach from 14 to 25 river miles upstream from the damsite. In that reach, the riverbed elevation varies from Elev. 4405 at Mile 14 to Elev. 4465 at Mile 25. At Mile 14, the bottom of the buried channel, on which the aquifer generally centers, turns away from the present river channel, and where it passes the damsite it is about 5 mi. from the river (just South of Bijou No. 2 Reser- voir). We suspect that there is only extremely limited communication between the aquifer and the present river channel downstream from River Mile 14 to well below the damsite. There seems little doubt that the known heavy downward leakage of Bijou No. 2 Reservoir is due to its proximity to the buried aquifer, since the present ground wa- ter table at this vicinity, as determined in the aquifer, is about 70 ft. below ground surface. We have reviewed the USGS study (Open File Report 76-379) which, among other items, evaluates the effects of Narrows Reservoir operation on performance of the aquifer, assuming a steady reservoir level of Elev. 4404, a reasonable assumption for non-transient, prudent ma.ximum, operating conditions. The study concludes that a stable reservoir at Elev. 4404, which incidentally would have almost no effect at the postulated aquifer intake reach, would at most raise the aquifer pressure about 20 ft. below Bijou Reservoir. Hence, the unsaturated thickness of alluvium there, iI isolated from e.'dended surface flooding, would amount to about 50 ft., and no foundation stabil- ity problem at the proposed dam could exist. In fact, it is shown that, if 'rapid communication between the ground surface and the aquifer locally exists, the aquifer would act as a massive underdrain for surface flooding. We have also reviewed the very thorough seepage analyses of a portion of the right abutment area, as basically affected by surface flooding, performed by USBR and dated November 8, 1977. We are impressed by the analytical skills demonstrated by the analyses, the scope of the work, and the finding that relief wells along the down- stream. toe of the dam would be highly effective in preventing serious seepage exit gradients. 13.