RioGrande_fs

• Year: 2002
• Title: Rio Grande Basin Facts
• Author: CWCB
• Description: Rio Grande Basin Facts Sheet
• Publications - Doc Type: Basin Fact Sheets

Unique Characteristics

'" Approximately 2,700 square miles in the San Luis
Valley form an internal drainage called the Closed
Basin, for which there is no surface outlet to the
Rio Grande.

t.\ The Closed Basin Project is a system of 170 salvage
wells which draw from the shallo~ unconfined
aquifer and salvage water that otherwise would be lost
to evapotranspiration.

. San Luis Valley irrigation relies heavily upon conjunc-
tive use of groundwater and surface water. An
estimated 85 to 90 percent of irrigation water in the
central part of the valley is from managed recharge
and pumping of unconfined-aquifer wells.

t\ Development of new supplies may be affected by
the Rio Grande Compact, endangered species,
interstate litigation, and overappropriated surface and
groundwater sources.

Source: Colorado Water Conservation Board

Wet and Dry Periods

Every year, Colorado experiences at least one 100-year flood
somewhere in the state. Colorado's total flood losses to date
have been documented to be $4.9 billion. The basin's most
recent flood event was June 9, 1985. The estimated total
historic flood damages for this basin are $12.1 million to
date.

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Dry Avg Wet

Oct 1911
Basin floods
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June 1927
Basin floods
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June 1941
Basin floods
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-=--=-

June 1985
Basin floods
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Major Imports into the Basin

Name Recipient Diversions
Stream (acre-feet)

1 * Tarbell Saguache 310
2 Weminuche Pass Ditch Weminuche 652
3 Pine River-Weminuche Weminuche 433
Pass Ditch
4 Wms Cr.-Squaw Pass D. Squaw 308
5 Don La Font D. 1 & 2 Red Mountain 198
6 Treasure Pass Ditch Pass 98
7 Tabor Pass Ditch Spring 846

Major Exports from the Basin

Name

Diversions
(acre-feet)
117
1,047

8 Hudson Branch Ditch
9 Medano Ditch

* Numbers in the above tables correspond to numbers that
accompany arrows on the basin map (p. 5).

Source: Division 3 1998 Annual Report, 10-year Averages

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Great Sand Dunes National Park (Photo courlesy of Adam Bingham)

Sept 1970
Basin floods
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Source: Colorado Water Conservation Board; and McKee, Doesken, and Kleist, Historical Dry and Wet Periods in Colorado, Figures, Colorado
Climate Center, Colorado State University, 1999.

( Rio Grande Basin Facts - 3 )