Hays Trinity GCD declares drought for Jacob’s Well GMZ

Hays Trinity Groundwater Conservation District Press Release [8/18/2020]:

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Effective August 1, the Hays Trinity Groundwater Conservation District Board of Directors voted to move the Jacobs Well Groundwater Management Zone (See Map) into 20% Curtailment drought status.

The 20% curtailment will help prolong groundwater availability for all users. Permittees operating within the Jacobs Well Groundwater Management Zone (JWGMZ) are required to reduce pumpage by 20% to extend supplies until the area receives enough rainfall to sufficiently recharge the aquifer. Groundwater users—whether served by a water utility or well–should reduce water use by 20%, which is usually achieved by limiting outdoor water use.

“The full heat of summer is upon us — and if hot and dry conditions persist through the month, the entire District should expect to move into drought curtailment in September,” said Linda Kaye Rogers, HTGCD Board President. “It is critical that we all conserve where we can by cutting back on outdoor usage.”

The Hays Trinity Groundwater Conservation District reports that District-wide, wells are experiencing sharply declining water levels. District and volunteer citizen monitor wells are down 5 percent from June and below levels seen last August. District monitor wells in the northwestern quarter of the District are at their lowest levels on record.

“Local well drillers are reporting an increase of dry-wells,” said District General Manager Charlie Flatten “they are recommending limiting unnecessary pumping to protect your pump from burning out.”

Jacobs Well spring flow is the District’s trigger for drought curtailment in the JWGMZ because it is an indicator of groundwater storage within the zone. 20% Curtailment is called for if flow drops below a 10-day average of five cubic feet per second (CFS) as measured by the US Geologic Survey (USGS) flow gauge at the spring. Average spring flow exceeding 6-CFS over an 10-day period will bring the JWGMZ out of drought curtailment.

The immediate rainfall forecast shows no major rain events in the near future. The National Oceanic and Atmospheric Administration (NOAA) predicts very little rainfall and higher than average temperatures through the rest of the summer.

The Texas Water Development Board recognizes that Hays County and much of Central and West Texas continues to experience Moderate to Extreme drought conditions. Many residents in the Wimberley Valley are already under conservation restrictions. Please visit the Hays Trinity Groundwater Conservation District website for more drought information and tips on conservation at home.


Hydrographs showing springflow that is currently providing baseflow for the Cypress Creek and Blanco River. [click image to visit Water Monitoring page]
Flow at Jacob’s Well has dropped below the drought threshold triggering a drought declaration by the Hays Trinity Groundwater Conservation District at the August 6 Board Meeting.  With the Jacob’s Well Groundwater Management Zone (GMZ) drought declaration, permittees operating wells within the GMZ are required to reduce pumpage by 20% to extend diminished groundwater supplies. For groundwater users and residents supplied by groundwater supplied water utilities, a 20% reduction in water use is easily achieved by limiting outdoor water use.  Conservation now will help protect water availability during these dry times.

Jacob’s Well GMZ drought stage.

Water levels within the aquifer upgradient (or uphill in groundwater terms) have been declining since early summer.  With high water use and hot temperatures, monitor wells traditionally show sharp declines during the summer months.  The last significant rain event happened on May 25 (with 2.5 inches recorded at the EAA weather station on the Blanco River near Burnett Ranch Road).  There has been little to no recharge to replenish groundwater supplies.  As a Middle Trinity Aquifer spring, Jacob’s Well flow serves as an indicator of groundwater storage in the Jacob’s Well GMZ.

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