Assessment of Groundwater Depletion and Implications for Management in the Denver Basin Aquifer System

Abstract

AbstractThe Denver Basin Aquifer System (DBAS) is a critical groundwater resource along the Colorado Front Range. Groundwater depletion has been documented over the past few decades due to the increased water use among users, presenting long‐term sustainability challenges. A spatiotemporal geostatistical analysis is used to estimate potentiometric surfaces and evaluate groundwater storage changes between 1990 and 2016 in each of the four DBAS aquifers. Several key depletion patterns and spatial water‐level changes emerge in this work. Hydraulic head changes are the largest in the west‐central side of the DBAS and have decreased in some areas by up to 180 m since 1990, while areas to the northwest show increases in hydraulic head by over 30.5 m. The Denver and Arapahoe aquifers show the largest groundwater storage losses, with the highest rates occurring in the 2000s. The results highlight uncertainty in the volumetric predictions under various storage coefficient calculations and emphasize the importance of representative aquifer characterization. The observed groundwater storage depletions are due to a combination of factors, which include population growth increasing the demand for water, variable precipitation, and drought influencing recharge, and increased groundwater pumping. The methods applied in this study are transferable to other groundwater systems and provide a framework that can help assess groundwater depletion and inform management decisions at other locations.