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Ground-water pumping impacts on surface water irrigation diversions from Big Lost River Item Info

The water table in the Big Lost River valley is declining due to increased irrigation pumpage and decreased recharge from surface-water irrigation, resulting from the use of more efficient application methods and an accompanying expansion to about twice the irrigated acreage of two decades ago. The lower water table reduces the already deficient river flows, and impacts the senior water rights of many surface water irrigators. Recorded irrigation diversions have decreased in relation to river flow in the last two decades. Diversions are estimated to be depleted by about 30,000 acre-feet per year in dry periods, such as 1987 and 1990. Depletion of diversions is estimated by a linear relationship to river flow, based on data from below normal water years. Extrapolating that relationship to all years, the depletion in a normal water year is estimated to be 13,000 acre-feet. A negative relationship between ground-water pumpage and river flow was extrapolated to estimate pumpage as 47,000 acre-feet during a normal water year. Senior surface-water irrigators are due mitigation from those depleting river flows. The mitigation may take any of several forms, but should be supported by a self-funding group of ground-water, or combined surface and ground-water irrigators in the valley.

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Title:
Ground-water pumping impacts on surface water irrigation diversions from Big Lost River
Authors:
Johnson, Gary S.; Ralston, Dale R.; Mink, Leland L.
Date Created (ISO Standard):
1991-12
Description:
The water table in the Big Lost River valley is declining due to increased irrigation pumpage and decreased recharge from surface-water irrigation, resulting from the use of more efficient application methods and an accompanying expansion to about twice the irrigated acreage of two decades ago. The lower water table reduces the already deficient river flows, and impacts the senior water rights of many surface water irrigators. Recorded irrigation diversions have decreased in relation to river flow in the last two decades. Diversions are estimated to be depleted by about 30,000 acre-feet per year in dry periods, such as 1987 and 1990. Depletion of diversions is estimated by a linear relationship to river flow, based on data from below normal water years. Extrapolating that relationship to all years, the depletion in a normal water year is estimated to be 13,000 acre-feet. A negative relationship between ground-water pumpage and river flow was extrapolated to estimate pumpage as 47,000 acre-feet during a normal water year. Senior surface-water irrigators are due mitigation from those depleting river flows. The mitigation may take any of several forms, but should be supported by a self-funding group of ground-water, or combined surface and ground-water irrigators in the valley.
Subjects:
Water management Surface water availability Groundwater depletion Pumping Irrigation Water rights
Location:
Big Lost River
Latitude:
43.94
Longitude:
-113.65
Collection:
Boise Basin
IWRRI number:
199112
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
Publisher:
Idaho Water Resources Research Institute; University of Idaho
Contributing Institution:
University of Idaho
Type:
Text
Format:
application/pdf
Cataloger:
KIT
Date Digitized:
2017-09-14

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Source
Preferred Citation:
"Ground-water pumping impacts on surface water irrigation diversions from Big Lost River", Idaho Waters Digital Library, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/iwdl/items/iwdl-199112.html
Rights
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
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