Laserfiche WebLink
<br />Current information regarding the specific location(s) and volume(s) of any new reservoir(s) is <br />insufficient to accurately predict these impacts. Impacts of new reservoirs would be addressed in <br />separate, site-specific Section 7 consultations; however, the expectation is that their depletions <br />would be covered by the PBO for this management plan up to the first 30,000-AF increment of <br />depletions (see the section entitled DeDIetion Accountinl! on page 30). At such time as future <br />depletions from the Yampa Basin approach this first increment, an intra-Service Section 7 <br />consultation would be reinitiated as required by the PBO to address the impacts of developing an <br />additional 20.000-AF increment of depletions. <br /> <br />Yarripa River flows were modeled in CRDSS under historic, current and future demands (limited <br />by 1998 supplies and institutional constraints) to assess the impacts to base flows due to current and <br />future depletions in Colorado in historical context. These data provided the basis to estimate <br />volumes of water needed to augment instream flows for the endangered fishes within the critical <br />habitat reaches of the Yampa River (see the section entitled Provide and Protect I"stream Flows <br />beginning on page 32). Current depletions (Table 5) are intermediate between historic and future <br />depletions (Table 9). <br /> <br />Table 9. Historic and future depletions from the Yampa Basin in Colorado by sector <br /> <br /> Average annual CRDSS depletions (AF) <br /> Sector Historic Demand 2045 Demand a Difference <br /> Agriculture (irrigation) 81,116 87,755 6,639 <br /> Municipal & Industrial (M&I) 4,012 15,100 11,088 <br /> Thermoelectric Generation 8,680 32,350 23,670 <br /> Exports (trans-basin diversions) 2,388 2,814 426 <br /> Reservoir evaporation 7,649 12,543 4,894 <br />I TOTALS I 103,845 I 150,562 I 46,717 I <br /> <br />a Limited by 1998 supplies and legal constraints; agriculture affected by senior M&I and <br />power (excludes shortages of 4,8 13 AF). <br /> <br />Because water would have t<> be released from storage to serve average annual depletions above <br />150,562 AF, depletions in excess of this amount should have minor, if any, impact to base flows. <br />Moreover, return flows to the river from water stored on the peak. of the hydrograph and released <br />during base flow periods potentially could increase base flows and reduce both the frequency and <br />magnitude of base flow augmentation needed in the future. Therefore, the estimated volwne needed <br />to augment base flows to compensate for an initial 30,000-AF increment of depletions is believed <br />to be sufficient to satisfy a second 20,000-AF increment, as well. <br /> <br />Management Plan for Endangered Fishes in the Yampa Ri ver Basin <br /> <br />24 <br />