Laserfiche WebLink
<br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />COO:9~ <br /> <br />Prewitt Reservoir. The inlet canal to the Prewitt Reservoir diverts <br /> <br />from the river 2.1 miles upstream from the Balzac gaging station. Releases <br /> <br />from the reservoir come back into the river about 5.8 miles downstream from <br /> <br />the gage. The Prewitt Reservoir has an available storage capacity of <br /> <br />28,960 acre-feet which is divided into 31,000 rights. The rights are <br /> <br />held as follows: <br /> <br />1. Logan Irrigation District--17,000 rights <br />(includes the South Platte, Pawnee, Davis Bros., Schneider and <br />Springdale ditches) <br /> <br />2. Iliff Irrigation District--8,OOO rights <br />(includes the Bravo, Farmers, Iliff and Platte Valley, Lone Tree, <br />Powell, Harmony No.2, Ramsey and Harmony No. 1 ditches) <br /> <br />3, Morgan-Prewitt Reservoir Company--6,000 rights <br />(Some of these rights are used by exchange upstream, but most <br />are held by individuals under nearby downstream ditches such <br />as the South Platte, Pawnee, Davis Bros., Springdale and <br />Sterling No.2.) <br /> <br />During the IS-year study period, an average of 41,000 acre-feet of water <br /> <br /> <br />was diverted from the river to storage and an average of 10,400 acre-feet <br /> <br /> <br />was released back to the river (USBR, 1965). Storage records show that <br /> <br /> <br />there was 1,950 acre-feet more storage in January 1, 1962, than on <br /> <br />January 1, 1947. Therefore the estimated average efficiency of the study <br /> <br /> <br />period was 30 percent to the outlet of the reservoir. The water released <br /> <br /> <br />to the river suffers losses in transit to the receiving ditch (as much as <br /> <br /> <br />40 river miles downstream) and in the receiving ditch before delivery to <br /> <br /> <br />farm headgates. <br /> <br />A large portion of the loss in the Prewitt Reservoir system is by <br /> <br /> <br />seepage from the reservoir. Officials report that the seepage rate from <br /> <br /> <br />the reservoir when it is full is 130 acre-feet per day. This water becomes <br /> <br /> <br />available for diversion by ditches and wells downstream, although there is <br /> <br /> <br />a significant loss to evapotranspiration from a high water table and phreato- <br /> <br /> <br />phytes supported by the seepage between the reservoir and the river. <br /> <br />South Platte Ditch. The South Platte Ditch diverts from the river 1.6 <br /> <br />miles downstream from the Balzac gaging station and serves about 4,900 <br /> <br /> <br />acres of irrigated land on the south side of the river, The average annual <br /> <br /> <br />diversion during the 1947 to 1961 study period was 10,400 acre-feet, rang- <br /> <br /> <br />ing from a minimum of 7,700 acre-feet in 1959 to a maximum of 13,400 acre-feet <br /> <br />-37- <br />