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

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

Each of these items was analyzed, reviewed with the Study Advisors and included

in a model of the operation of the Rio Grande within Colorado. The model was

then used to estimate storable flows at four potential reservoir sites for

several water supply/demand scenarios. The analyses are summarized in the

following paragraphs.

Reservoir Sites

Storable flow was investigated at the four potential reservoir sites indicated

below. The latter two sites were selected during this study following a review

of factors influencing physical and legal water availability in selected reaches.

1 )

the Wagon Wheel Gap site on the Rio Grande approximately 32 miles

upstream from Del Norte, Colorado,

the Vega Sylvestre site on the Rio Grande approximately 49 miles

upstream of Del Norte,

a site (called RGt) on the Rio Grande located approximately 14 miles

upstream from Del Norte, and

a site (called SFl) on the South Fork approximately 6 miles upstream

from the town of South Fork, Colorado.

2)

3)

4)

Water Rights Administration

In Colorado, the basic water allocation principle is the prior appropriation

doctrine which can be expressed as "first in time, first in right". The

appropriation date and adjudication date of a water right become the basis for

determining which users are entitled to the river flow during a period when there

is insufficient water for all appropriators.

Water use and water rights administration in the Conejos Basin, the largest

tributary to the Rio Grande within Colorado, have developed independently of

water use and water rights administration on the mainstem of the Rio Grande.

Legal water availability at the four potential reservoir sites would be affected

by water rights administration of mainstem water rights but would be unaffected

iii