Laserfiche WebLink
<br />-----y-- - -- <br /> <br />OO~~75 <br /> <br />November exhibits slightly less augmentation demand than either October or December. This dip <br />in demand may be indicative of the so-called "bounce" in the hydrograph at this time of year, <br />typically after irrigation diversions cease. This pattern has been attributed to latent return flows to <br />the river from irrigation earlier in the year (September-October). However, the rise in base flows <br />may be a natural phenomenon due to cooler temperatures, the onset of vegetation winter dormancy, <br />and correspondingly lower transpiration losses. <br /> <br />Formulation of an Augmentation Strategy <br /> <br />A variety of augmentation water supply alternatives, with and without storage, were identified and <br />evaluated. "Non-structural" options do not utilize storage, but rely instead on instream flow water <br />rights or supply interruption contracts with water users. These contracts also could involve water <br />conservation measures to make more water available for purchase. Supply interruption contracts <br />also were evaluated in combination with structural options. <br /> <br />"Structural" options rely on storage in new and/or existing reservoirs, including leases or contracts <br />for water from existing storage. Eleven alternatives rely on structural options or a combination of <br />structural and non-structural options. The following structural sources were evaluated: <br /> <br />. Steamboat Lake (by lease) <br />. Elkhead Reservoir (by lease, exchange and/or enlargement) <br />. Stagecoach Reservoir (by lease, exchange and/or enlargement) <br />. New tributary reservoir(s) <br /> <br />Steamboat Lake is 26 highway miles north of Steamboat Springs, Colorado, on Willow Creek, a <br />tributary to the Elk River, 33 RM upstream from the Yampa River and 77 RM upstream from Craig, <br />Colorado. Covering 1, I 00 surface acres, this reservoir provides both storage and water-related <br />recreation, with a total storage capacity of about 26,000 AF, including 18,068 AF for recreation and <br />5,000 AF for industrial purposes (Table 4). Up to 3,300 AF also is available for instream flow. <br />In the past, the Recovery Program augmented Yampa River flows with 2,000 AF from this pool, <br />which the Service leased from Parks. Up to an additional 1,300 AF of water could be leased subject <br />to availability. The entire 3,300 AF has been decreed for instream use, and the Service sublet it to <br />the CWCB for this purpose. Water was released from Steamboat Lake at the request of the Recovery <br />Program and CWCB to serve the instream flow needs of the endangered fishes. The Colorado Slate <br />Engineer delivered the water from Steamboat Lake downstream to the Deerlodge Park gage, less <br />any transit losses. The lease expired on September 30, 1999, and new terms have not be negotiated. <br />Several of the structural alternatives include leasing water from this reservoir, the cost of which <br />would be borne by the Recovery Program. <br /> <br />Elkbead Reservoir covers about 675 surface acres on Elkhead Creek, 8 RM upstream from the <br />Yampa River and about 17.5 RM upstream from Craig, Colorado. This 13,700-AF reservoir <br />provides both water storage and recreation, including 8,3 lOAF for industrial purposes, 1,668 AF <br />for municipal purposes and 3,722 AF of dead storage (Hydrosphere 1995). There is no current <br />storage volume available nor allocated to augment stream flows. To create a pool for this purpose <br />in Elkhead, it would be necessary to either enlarge the reservoir or purchase or lease water from one <br />or more of the existing pools. <br /> <br />Management Plan for Endangered Fishes in the Yampa River Basin <br /> <br />42 <br />