How groundwater pumping affects streamflow

system to recover from the previous pumping stress. In some aquifers, maximum rates of streamflow depletion may occur long after pumping stops, and full recovery of the groundwater system may take decades to centuries.

  • Streamflow depletion can affect water quality in the stream or in the aquifer. For example, in many areas, groundwater discharge cools stream temperatures in the summer and warms stream temperatures in the winter, providing a suitable year-round habitat for fish. Reductions in groundwater discharge to streams caused by pumping can degrade habitat by warming stream temperatures during the summer and cooling stream temperatures during the winter.
  • The major factors that affect the timing of streamflow depletion are the distance from the well to the stream and the properties and geologic structure of the aquifer.
  • Sustainable rates of groundwater pumping near streams do not depend on the rates at which groundwater systems are naturally replenished (or recharged), but on the total flow rates of the streams and the amount of reduced streamflow that a community or regulatory authority is willing to accept.

    • “Conjunctive management of groundwater and surface-water resources is critical in New Mexico, where our limited surface-water supplies can be impacted by new uses that are predominantly dependent on groundwater pumping,” said Mike Johnson, chief of the Hydrology Bureau in the New Mexico Office of the State Engineer. “This new USGS publication consolidates our understanding of the connection between aquifers and streams and provides a clear, thorough and up-to-date explanation of the tools and techniques used to evaluate streamflow depletion by wells.  This report will be very useful to New Mexico’s water managers in guiding technical analysis, dispelling common misconceptions, and explaining these complex concepts to decision makers and the public.”

    The report, which is a product of the USGS Groundwater Resources Program, is titled “Streamflow Depletion by Wells — Understanding and Managing the Effects of Groundwater Pumping on Streamflow” and is available in print and online.

    USGS notes that the Groundwater Resources Program provides objective scientific information and develops the interdisciplinary understanding necessary to assess and quantify the availability of the nation’s groundwater resources. The Program has been instrumental in documenting groundwater declines and in developing groundwater-flow models for use in sustainably managing withdrawals. The research and understanding developed through this program can provide water-resource managers with the tools and information needed to manage this important natural resource.

    — Read more in Streamflow Depletion by Wells — Understanding and Managing the Effects of Groundwater Pumping on Streamflow