Quantifying Groundwater Resilience

Posted by Karen Ray on September 14, 2018 6:55 PM

Quantifying groundwater resilience through conjunctive use for irrigated agriculture in a constrained aquifer system

Erek H. Fuchs, Kenneth C. Carroll, James P. King

Fuchs–Groundwater Resources Manager for Elephant Butte Irrigation District, Las Cruces, NM 88001, United States
Carroll–Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM 88003, United States
King–Department of Civil Engineering, New Mexico State University, Las Cruces, NM 88003, United States

To read entire article go to :

(Journal of Hydrology 565 (2018) 747–759)

Abstract

The Rincon Valley in arid, south-central New Mexico, is especially impacted by reduced
surface water supply because the contribution of groundwater is limited by aquifer constraints.
Consecutive surface water allotment shortages in the Elephant Butte Irrigation District (EBID)
have reduced recharge. The effects are compounded by farmers continuing to extract
groundwater to meet crop requirements. Conjunctive use assumes aquifer resilience (i.e.,
ability to absorb pumping stress), but not necessarily in drought. This study further develops
the water table fluctuation method by analyzing data from the EBID’s groundwater monitoring
program to reveal conjunctive use controls over the spatial and interannual variability of net
storage changes from 2009 to 2016 in the Valley and introduces the term groundwater-surface
water ratio of application (GSRA), that has potential for characterizing system resilience in
conjunctive use settings. Regression modeling shows that variation in the annual EBID surface
water allotment correlates strongly with year-end water table elevations, even more strongly
than total annual groundwater extractions for irrigation, suggesting that variable surface water
allotments are a primary driver of this system. Dewatering of the aquifer as of 2011
significantly altered the system hydrology such that from 2011 to 2016, net change in storage
correlates strongly with the annual surface water allotment, corresponding to large river losses
for the same period, but resulting in net gains in storage from 2014 to 2016. Rapid storage loss
and rebound in this constrained aquifer system allowed quantification of aquifer resilience,
enabling the development of a GSRA as a potential planning metric.