What is this project?
Artificial ground-water recharge has long been recognized as a water-resources management tool for introducing water into the ground-water system to store water, reduce pumping lifts, salvage storm-water runoff, or enhance ground-water quality. Using this approach, ground-water aquifers are used as water-storage facilities similar to surface-water reservoirs. Aquifer Storage and Recharge (ASR) projects involve the storage of water in an aquifer when water is available, and recovery of the stored water from the aquifer it is needed. Artificial ground-water recharge can be accomplished by surface spreading (ponding) of water in areas where surface deposits are highly permeable, or by injection of surface water into an aquifer using wells. The Weber River Aquifer Storage and Recovery Project uses water diverted from the Weber River to recharge the principal ground-water aquifer (Delta aquifer) in the Davis and western Weber Counties area. The project uses surface ponds located near the mouth of Weber Canyon pictured below, view is to the southeast.
Why was this site chosen?
There are good reasons to believe this project will be successful at this site. In 1952, the U.S. Bureau of Reclamation conducted a series of ground-water recharge experiments near the mouth of Weber Canyon. The purpose was to determine whether surface infiltration at this location would recharge the Weber Delta Aquifer.
These experiments were very successful. Using the gravel pit nearest the mouth of the canyon, U.S. Bureau of Reclamation measured an infiltration rate of approximately 7 cubic feet per second per acre. There was a hydraulic response to this recharge in several monitoring wells located near the site and several miles away. The experiments lasted seven weeks and added approximately 2,200 acre-feet of water to the ground-water aquifer.
Why is this project needed?
Ground-water levels in the Ogden area have been declining since the 1950's according to Utah Department of Water Resources. This is due to increased withdrawals from wells for municipal and industrial use. From 1953 to 1985 water levels declined an average of 27 feet in the Ogden area, with a maximum drop of 50 feet in some areas. Water levels in wells in the recharge area near the mouth of Weber Canyon declined as much as 40 feet during the same time period. The U.S. Geological Survey documented water level declines of up to 30.8 feet from 1970 to 2000.
In 2004, the Utah Division of Water Resources did a study of ground-water declines in the Delta aquifer. Using U.S. Geological Survey monitoring well data, they determined that from 1950 to 2004 water levels have dropped from 50 to 67 feet over an area of more than 40 square miles. They also found that at the current rate of ground-water decline, salt water intrusion into the fresh-water aquifer was a risk within the next 25 to 30 years.
Purpose of Pilot Project
In the summer of 2002, the U.S. Bureau of Reclamation approached the Utah Division of Water Resources and the Weber Basin Water Conservancy District seeking water-supply topics within the basin that needed further study. The three agencies decided to initiate an Aquifer Storage and Recovery pilot project at the mouth of Weber Canyon. Later, the Utah Geological Survey, Weber State University, and University of Utah joined the project team. Using the knowledge gained, the Conservancy District intends to eventually expand into a permanent large-scale recharge facility. A permanent facility would help address several water-supply problems including the following:
In addition to the benefits that the Weber Water Conservancy District Basin will realize, a successful project would positively influence the use of this technology throughout the rest of the state. Much has been learned already, and this knowledge is forming a solid foundations for future projects.
View Updates of the Pilot study that began in March 2004