WSP01461

• File Number: 8549.800
• Description: Rio Grande Basin-Miscellaneous Small Projects and Project Studies-Rio Grande Assessment
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 2/1/1981
• Author: Brandes Kier Stecher
• Title: Water Resources Reference Base for the Assessment of the Rio Grande Region
• Water Supply Pro - Doc Type: Report/Study

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evaporation. For the period 1955-1974, the average annual evaporation loss
from Elephant Butte and Caballo Reservoirs was 63,000 and 26,000 acre-feet,
respectively [13]. Based on average measured pan evaporation rates [4] and
conservation pool surface areas for Amistad and Falcon Reservoirs, the quan-
tities of annual evaporation loss from these impoundments have been calcu-
lated to be approximately 400,000 and 600,000 acre-feet, respectively.
Actual evaporation losses during the past ten to fifteen years have been
less in both of these impoundments, however, since their average storage
volumes have been below conservation pool levels by about 20 percent.

IMPORTS/EXPORTS

The major import of water into the Rio Grande Region is through the San
Juan-Chama Diversion Project. Water from the Colorado River Basin in north-
western New Mexico and southwestern Colorado is collected and transported
into the Rio Chama Basin, a major tributary of the Rio Grande in WAU 130201.
This project was completed by WPRS in 1970, and its purpose is to provide
110,000 acre-feet of water annually to supplement municipal, industrial and
irrigation water supplies in the middle Rio Grande Basin of New Mexico and to
provide a recreation pool in Cochite Lake. Major annual allocations of the
water include 48,000 acre-feet for the City of Albuquerque, 20,900 acre-feet
for the Middle Rio Grande Conservancy District, 5,600 acre-feet for the City
of Santa Fe, and 8,400 acre-feet for evaporation loss in Heron Reservoir,
the major storage impoundment for project water in the headwaters of the
Rio Chama Basin [18].

Minor interbasin diversons of surface water into the Rio Grande Basin of
Colorado (WAU 130100) are made from the Gunnison and San Juan River Basins in
southwestern Colorado. Approximately 4,000 acre-feet are imported annually
and used primarily for irrigation [7].

The only export of water from the Rio Grande Region occurs in the lower
Rio Grande valley of Texas (WAU 130900) where major irrigation diversions are
made outside of the IBWC flood control levees. Approximately one million
~re-feet of water are diverted annually from the River into the Nueces-Rio
C'6'OO

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