WSP05149 - Laserfiche WebLink

Home Browse Search

w. I. I"J \. I~ . ~ w J, ~~tr~ fp.' ~ . ! . . a m 0) w mile of drainage basin. Using the above rate and applying it to the drainage basin above the Piedmont Bridge Reservoir results in a siltation rate of 607 acre-feet per year. Some authorities on sediment are of the opinion that, the best method for esti- mating the rate of siltation of a reservoir in one drainage basin is by the use, if possible, of actual experience in a drainage basin of similar characteristics. In analyzing the problem at Trinidad, it is believed that the bed load will not exceed 25 percent of the measured load and that about IO percent of the total load will be deposited above the ba,clcwater in the reservoir and passed through the dam by stratified flow and the sluicing action of released water. These criteria give an average siltation ra.te of 612 acre-feet per year. A siltation rate of 610 Hcre-feet therefore has been adopted for these studies. Irrigation Benefits. Most of the irrigation benefits that would result from the construction and operation of the Piedmont Bridge Reservoir would be the regu),ation of water now being di- verted, making the regimen of flow more nearly parallel with irrigation requirements. Such irrigation benefits would result from increased crop production of the type of crops now being raised, and some change in the crop pattern permitting of the raising of larger acreages of high-price late-season annual crops. The maximum benefit to the area would result from the pooling of all of the water and the water rights, those entering the pooling agreement to receive equivalent service from the reservoir. In cases when tile reservoir would be empty, it would be assumed. that the priority system would a.gain become operative. -12-