Playa Lakes: Enchancing Recharge to the Ogallala Aquifer

Project Goals

  • Overall Goal: Increase recharge to the Ogallala Aquifer from the 20,000 Texas playa lakes
  • Phase 1—Initial three years of monitoring completed: Quantify volume of water in playas and measure current recharge rates from selected playas
  • Phase 2—Pending $1 million additional funding: Playa modifications to assess potential for increasing recharge to the Ogallala Aquifer

Status

  • Five years of Phase 1 monitoring has been completed. More than 100 flood events were observed, ranging in size from < 1 acre-foot to nearly 1000 acre-feet in volume.
  • Access agreements were completed with 36 landowners.
  • Monitoring equipment was installed in 38 playas in 13 counties across the Panhandle.
  • Topographic surveys and satellite data were used to develop flood histories for 72 playas.
  • Research cooperation was established with groups from Texas Tech, the US Department of Agriculture - Agricultural Research Service, and Clemson University.
  • Technical reports are in preparation.
  • Intensive field monitoring will be discontinued at most sites in early 2016. Water level monitoring will continue at all sites pending Phase 2 approval.

Major Findings

  • The volume of water collected in playas from 1996 to 2014 averages 200,000 acre-feet per year, significantly less than estimated by previous studies. Long-term trends of increasing evaporation and observed declines in playa water volume between 1996 and 2014 suggest that less water may be available from playas in the future.
  • Current recharge rates measured at instrumented playas ranged near zero to more than one foot per year over the monitoring period; much of the region was in exceptional drought during 2011–2013.
  • Large, infrequent flood events produce most of the recharge. Exceptional flooding in 2015 produced more recharge than the previous four years together. Rapid infiltration from small floods on dry, cracked soil is typically held in the top 10 feet of the soil and can be transpired by plants during dry spells between floods.
  • Fifteen percent of the playas receive an average of more than a foot of water per year.

Potential Impact

  • Enhanced playa recharge may provide a sustainable local water resource but won’t substantially change the overall water budget for the Ogallala. The TWDB Groundwater Availability Model for the Southern High Plains estimated total recharge at 1,032,905 acre-feet in 2000; recharge enhancements at the 3000 wettest playas might gain 40,000 to 80,000 acre feet per year.
  • The 200,000 acre feet of water collected annually by Texas playas represents less than four percent of the 5.6 million acre-feet of 2010 irrigation demand for Regions A and O.

Additional Information


TWDB Reports


External Links


External Reports


Groundwater Conservation Districts

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