WSP05772 - Laserfiche WebLink

Home Browse Search

. l 0766 . . uncontrolled area such that the flood peaks from the uncontrolled area would not be materially increased. The effect of the Trinidad Reservoir operation for flood control on all floods at Trinidad, COlorado, which occurred during the 30-year period from January 1, 1921, through Decem- ber 31, 1950, was estimated. The effect was also estimated on the maxi- mum kn01<Tn flood which occurred in September 1904. Runoff from the uncon- trolled drainage area (97 square miles) together with the flow through the outlet works anj the uncontrolled notch from all the above floods at Trinidad would :;.c:.:oss than 15,000 cubic feet per second. Flood peaks of record modified by the Trinidad Reservoir are shown in table 12. 52. The standard project flood peak flow from the uncontrolled drain- age aroa was estimated to be 28,000 cubic feet per second at Trinidad. The standard p1Dject flood for the drainage area above the Trinidad dam site would be controlled to a maximum outflow of 15,000 cubic feet per second. Since the peak produced by the standard project storm on the un- controlled drainage area occurred about three hours prior to the peak in- flow to the reservoir, flow past the dam site would not contribute to the peak of the flood from the uncontrolled drainage area. Plate 4 shows the discharge~frequency curve for regulated conditions at Trinidad, Colorado. 53. Effects of the project on Arkansas River water supply. _ Reservoir operation studies based on the period of record 1925-1949 were made by the Bureau of Reclamation and the Corps of Engineers to evaluate the effects of the irrigation storage and the regulation of the reservoir inflows for flood control, respectively, on the water supplies downstream from the project. These studies were needed to determine the project feasibility within the administration of the Arkansas River Compact. Operation of the reservoir for irrigation.under conditions a, b, and c was estimated to reduce the average annual usable water supply at John Martin Reservoir on the Arkansas River by 200 acre-feet. The regulation of the 39 APPENDIX B .