WSP06451

• File Number: 8460.500
• Description: Platte River Recovery Plan - SPDSS Studies ‎(see also 8483)‎
• Basin: South Platte
• Date: 6/5/1991
• Author: Univ. of Colorado
• Title: Colorado's Law of Underground Water" - A Look at the South Platte Basin & Beyond
• Water Supply Pro - Doc Type: Publication

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582

UNIVERSITY OF COLORADO LAW REVIEW

[Vol. 59

opment and use of these resources continued to proceed as if they were
separate and unrelated. No serious problems arose in Colorado until,
with the dramatic growth in groundwater pumping in the 19505 and
19605, it became evident that surface flows were being directly
impaired.9

III. DEVELOPMENT OF TRIBUTARY GROUNDWATER IN THE
SOUTH PU\ITE BASIN

The South Platte River drains the most populous and most agri-
culturally productive region of Colorado, The river and its major
tributaries head in the high mountains of the Front Range of Colorado
and drain northeast into the high plains, Intensive use of this modest
river during the past 120 years has radically altered its flow patterns.
Native water supplies, largely from high mountain snowmelt, are
about 1.4 million acre-feet in an average year. Historically, surface
water flows reaching into the plains area peaked with the snowmelt,
declining thereafter so that by late summer the riverbed often was
completely dry-especially at greater distances from the mountains,
Annual precipitation in this region of Colorado is very limited-about
10 to 14 inches per year,
Much of the South Platte River, especially that downstream from
Denver, is underlain by penneable material such as sand and gravel
long ago deposited in channels carved in bedrock, Over time, portions
of this alluvial fill became penneated by seepage from surface flows.
Substantial additional areas of alluvial fill underlying land adjacent to
surface streams have become saturated with water as a consequence of
seepage from irrigation water spread over the surface year after year.
Eventually the water table in this alluvial aquifer became higher than
the river bed. The resulting return flows to the river brought about
year.round surface flows, The alluvium in the reach of interest (down-

Along a water course where tbe dependable surface supplies are utilized for irrigation
and other purposes to the fullest practicable extent, the maximum beneficial utilization of
the total water resource will resul' from an intelligent coordinated use of the ground water
and surface water supplies both of which arc: intimately inter-related. and the proper utili-
zation of ground-water storage capacity. Utilization of the ground-water storage capacity
will be for the above-average surface water supplies, wl1ich will provide an increment of
stored ground water to be withdrawn during periods of below~average surface water
supplies.

Tipton Memorandum at 5.
9. In the Arkansas River valley tbefe were an estimated 40 irrigation wells in 1940 pumping
about 2,500 acre-feet of water. By 1972 the number ofwdls had increased to 1,477 and annual pump-
ing had grown to about 208,000 acre feet. Office of the State Engineer, State of Colorado, STREAM
DEPLETION BY WELLS IN THE AP.kANSAS RIVER. BASIN - CoLOItAOO, tables 6. 7 at 19, 22 (Mar.
1975) [hereinafter Arkansas Stream Depletions]. Similar growth occurred ill the South Platte. See text
accompanying notes 11.13.

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COLORADO LAW OF "UNDERGROUND WATER"

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