WSP06521

• File Number: 8111.831
• Description: Arkansas River Compact Administration - Article VIII ‎(H)‎ Investigations
• Basin: Arkansas
• Date: 1/1/1985
• Author: David Pope
• Title: Supplement Report to ARCA Regarding Article VIII ‎(H)‎
• Water Supply Pro - Doc Type: Publication

Based on an analysis of the tabulation of wells in-

cluded in the above referenced U.S.G.S. report, it is known

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that well development above John Martin Reservoir (Colorado
Water Districts 14 and 17) generally occurred prior to that

below John Martin (Colorado Water District 67). Half of the

irrigation wells between John Martin Reservoir and the

Colorado-Kansas stateline were drilled before 1962, but half

of the wells reported above John Martin were in existence

and in use prior to 1956.
As noted above, most of the alluvial wells are report-
edly used as a supplemental irrigation supply. Accordingly,

it is likely that annual well pumpage is highly dependent

upon quantities of water available from the surface water

supply. Thus, during drier than average years, when surface

water supplies are limited, well usage could be expected to

increase, and, during wet years, there may be little or no

need for irrigators to use their wells.

Without question, groundwater withdrawals by alluvial
wells impact streamflows. Stream depletions from the
pumping of alluvial wells is brought about primarily by the

interception and consumption of groundwater in transit to

the stream and secondarily by a flow reversal that occurs
when pumping lowers the water table elevation below that of
the stream bed. The timing of depletions from alluvial well
pumping is dependent upon the distance from the well to the

'stream and the characteristics of the groundwater aquifer;
For a well located immediately adjacent to a river, the

timing and pattern of depletions may closely follow the

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