WSP08501 - Laserfiche WebLink

Home Browse Search

Costs The 1980 cost estimate for construc- tion of the design project is $135 million. The interest cost during construction would be nearly $56 million. The annual costs for opera- tion, maintenance, and replacement would be $5.3 million. Impacts The investment required would total $191 million in construction costs and interest during construction. The net economic benefit would be -$78 million. The estimated impact on the water quality of the South Platte River Basin would represent a large nega- tive change from existing conditions. The estimated impact on the fish and wildlife of the South Platte River Basin would represent a moderate negative change from existing con- ditions as a result of the transfer of water out of the basin. Transbasin Exports (Alternative III-E) One plan transfering the water from the South Platte River Basin into the Republican River Basin is the Trans- County Project. The project involves two optional plans depending on the utilization of a downstream main- stem reservoir. The first plan would transfer flows from the downstream mainstream reservoir to the proposed Fremont-Butte Reservoir. The second plan would take water from the pro- posed Morgan-Beaver Reservoir, transfer it to the proposed Beaver Creek Reservoir and then transfer it to the Fremont-Butte Reservoir. Both pians would then transfer flows to three proposed High Plains reser- voirs. This water storage and distri- bution system would be known as the "upper unit." Water would ulti- mately be transferred throughout the Republican River Basin from these three High Plains reservoirs. 8 The "lower unit" would direct water from the mainstem South Platte River at Sedgwick to a pumping plant. Diverted flows would then be pumped up to the High Plains for distribution to three reservoirs. Surface water would be distributed to the Repuh- Iican River Basin for Irrigation from these three reservoirs. The proposed project would transport an estimated 160,000 acre-feet of direct irrigation water deliveries into the Republican River Basin. Conjunctive Surface Water/Groundwater Storage and Use (Alternative III-F) Conjunctive use of undeveloped streamflows of the South Platte River with groundwater and aspects of artificial recharge constitute this alternative. For purposes of this pre- liminary investigation, three areas for implementing programs of con- junctive use of surface/ground water were considered: the Henrylyn sys- tem, the Badger-Beaver system. and the lower South Platte River system. Based on the preliminary analysis, estimated water diversions from the South Platte River would total 191.000 acre-feet and water recharged to the alluvial aquifers would total 63,200 acre-feet. Water recovered through ?umping at the point of use (that is, m recharge areas) would equa142,200 acre-feet. The Henrylyn Irrigation District, lo- cated approximately 40 miles north- east of Denver, supplies irrigation water to ahout 33.000 acres in Pros- pect Valley, which is located at the eastern edge of the Henrylyn district. The district began a limited ground- water recharge program to mediate surface water shortages and water well declines. The program utilized seepage available from the Olds Reservoir to artificially recharge the alluvial aquifer. Additional seepage from the Lord Reservoir and the Denver-Hudson Canal contrihuted to the recharge. The reservoir underlying Prospect Valley can continue to be used COn- junctively with the surface irrigation system to provide long-term irrigation supplies for the area with the use of this limited ground water recharge program. The Badger-Beaver Water Conserv- ancy District has also formulated a conjunctive use plan. The plan would consist of both surface and subsur- face storage, change of a water right to an alternate point of diversion, and change of storage rights to an alternate point of diversion. Water would be diverted through the Beaver Canal to a small storage reservoir of 10.000 acre-feet to be called the Badger-Beaver Reservoir. Water would then be released for subsur- face storage in the alluvial aquifer, which has an estimated capacity of approximately 559,000 acre-feet. The water would be used for rural domestic, irrigated agriculture. rec- reation, artificial recharge, and for augmentation of the existing wells within the District. Several existing ditches in the lower South Platte River have been eval- uated as potential sites for artificial recharge and for developing high- capacity alluvial wells. An advisory committee has been formed to esti- mate the feasihility of recharge sites and supplemental well sites within the vicinity of these ditches. The lower South Platte River con- junctive use plan would be facilitated by a downstream mainstem reservoir approximately one-half the size of the proposed downstream main stem reservoir (Alternative III-A). Such a reservoir would require a conserva- tion storage capacity of about 225,000 acre-feet.