PUB00027

• Year: 1990
• Title: Final Report Rio Grande Water Supply Study, Phase 1
• CWCB Section: Interstate & Federal
• Author: San Luis Valley Water Conservancy District
• Description: Reconnaissance level determination of the physically and legally available flow at 4 reservoir sites in the Rio Grande Basin upstream of Del Norte, Colorado
• Publications - Doc Type: Brochure

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Flows, surplus to downstream irrigation diversions and the Rio Grande

Compact, existed in 36 consecutive years of the study period. For the

Alternate Step Two mainstem diversion scenario, no Storable Flood Flows

oc:turred.

No Debit Storable Flows occurred in the simulations. The modeling indicated

that the generally low levels of Rio Grande Project storage during the

study period required that the captured amounts of Colorado' s Compact

obligation be subsequently released to downstream states.

Tbere are potentially large volumes of Storable Seasonal Flow. The average

(1948-1985) annual Storable Seasonal Flow ranged from approximately 5,500

af to over 90,000 af depending on the assumed efficiency of the direct flow

irrigation systems, the potential reservoir site, and the mainstem

diversion scenario. Storable Seasonal Flows were available in greater than

65 percent of the years studied.

The analyses conducted for this study indicate that the downstream reservoir

sites, RGl on the Rio Grande and SFl on the South Fork, would have the greatest

potential for capturing storable flows. The RGl site displays the greatest

potential of all sites investigated. It should be kept in mind, however, that

a number of factors in addition to water availability must be considered in the

selection of a potential reservoir site. These other factors such as

geotechnical suitability, construction costs and environmental considerations

were beyond the scope of this study.

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