WSP07823 - Laserfiche WebLink

Home Browse Search

2311 In the preparation of reconnaissance cost estimates for the two alternate dO\lIlstream reservoirs each was considered to provide conservation capacity of 265,000 aLre-feet,after 50 years, and joint use capacity of 75,000 acre-feet for new control and necessary dead, sediment, flood control, and superstorage space as required for each site. In addition Weld County Reservoir would provide 94,000 acre-feet of capacity for the transfer of Empire and Riverside Reservoir rights. As a practical matter the potential Weld County Reservoir should provide capacity to permit the transfer of Empire and Riverside storage rights. If such capacity is not provided the d.ead storage space Will need. to be increased to permit operation of the existing feed.er canals leading to the Empire and Riverside Reservoirs or else a pump 11ft would be required.. Meeting either ore of these requirements would. make Weld County Reservoir impractical. Therefore, no investigation was made of this alternate. '. Bijou Creek Control Bijou Creek carries a very heavy sediment load; at its mouth it contributes even more sediment than the mainsteID of the South Platte River. If floods are controlled on the mainstem and not on Bijou Creek, sediment interference on the mainstem could. become intolerable. Therefore, Bijou Creek flood control is considered an essential adjunct of any mainstem control. A reservoir on Bijou Creek, near Hoyt, Colorado, has been considered for the purposes of flood control and recharging ground water in the critical Wiggins area. This reservoir, however, would not provide adequate control of sedilrents. ~:" HYDROLOGIC DATA Talting into consideration only the water supply and its utilization there is little difference whether the conservation storage is provided at the Weld County site or the Narrows site. One of the primary objectives of the Narrows Unit is to increase the amount and/or improve the timeliness of 'later deliveries to the basin users. Capacity at either site to store and regulate the available water supply will accomplish this objective. As previously explained, exchange practices ,~ll be required to make water available to upstream users except as may be served directly by storage works located above Denver. These exchanges, in general, could be effec- tively made from either of the proposed downstream reservoirs. There are few differences in hydrologic aspects of the two downstream sites. 3