Click on the image to see a larger version. Groundwater map showing changes in groundwater levels since pre-development. Source — UNL (Conservation and Survey Division, School of Natural Resources, Institute of Agriculture and Natural Resources, and College of Arts and Sciences), U.S. Geological Survey, Nebraska Natural Resources Districts, Central Nebraska Public Power and Irrigation District, Mark Burbach (Water Levels Coordinator, CSD).

Another important aspect of Central’s project is its impact on one of Nebraska’s most valuable resources: the underground aquifer. Recharge from Central’s system maintains groundwater levels in south-central Nebraska. Water that soaks into the ground recharges the underground water supply that is critical to farmers who use wells to irrigate their fields and to towns and cities in the area that pump groundwater to supply homes and businesses. Some of the water also moves underground back to rivers and streams in the area, helping to supplement stream flows.

Central undertook two major rehabilitation projects in the 1970s and 1980s on the E65 and Phelps Canals. During the planning stages for these projects, groundwater modeling studies helped engineers determine where it would be best to allow more recharge from the canals to benefit groundwater tables and where it would be best to install pipelines and lined canals to reduce the amount of water entering the groundwater table. The result has been a generally stable water table beneath and adjacent to Central’s service area.

It was the first time in Nebraska’s history that an irrigation system was designed to address the water supply and the needs of both surface and groundwater irrigators. This “conjunctive use” system recognizes the hydrological connection between surface water and groundwater.

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