• Please read our May Aquifer Health assessment. The monthly assessment utilizes the District’s monitoring network to… ,
Important New HTGCD Meeting Date!
now scheduled on 1st Thursday
but check the calendar.

Drought Management

The Hays Trinity Groundwater Conservation District is in 20% groundwater pumping Curtailment Stage District wide.

New Drought Contingency Plan containing updated Rules 13 and 15 is available here.

The HTGCD uses Pedernales and Blanco River streamflow as District-wide drought indicators because these rivers are recharge features of our aquifers. Aquifer recharge occurs relatively slowly, and streamflow indicates the current and future health of the Trinity Aquifer in the District -- and therefore determines what stage of drought we must observe.

Data shows healthy streamflow in the Perdernales River is above 31.6 cubic feet per second (cfs), and 28.5 cfs in the Blanco River. The District recommends conservative use of water when streamflow is healthy.

When streamflow drops below a drought trigger -- shown in the table below as "Alarm," "Critical," and "Emergency" -- a daily counter begins. If the counter for both drought indicators reaches 30 days, the District Board will declare the appropriate drought stage.

To move out of a drought stage, both drought indicators must flow 60 consecutive days above the current drought trigger in order to give aquifers time to recharge. The declaration of the District coming out of drought stage will go into effect on the next Board Meeting.

So, though Hays County may be out of atmospheric drought and have full ponds and lush landscape, the aquifer that feeds your well requires a longer time to catch up with the surface conditions.

Drought Stage
Stage Start Date: September 2020
Discharge Flow Rate 30 Day Mean 60 Day Mean Alarm Trigger Critical Trigger Emergency Trigger
Region K
Pedernales Rv nr Johnson City, TX (08153500) as of 2021-07-28 181.37 242.46  31.6  10.2 2.23
Days with flow Above Stage Trigger 59 59 59
Region L
Blanco Rv at Wimberley, TX (08171000) as of 2021-07-28 58.21 62.85  28.5  14.5 9.28
Days with flow Above Stage Trigger 58 58 58
Streamflow is measured by the United States Geological Survey (USGS) gages at the Blanco River in Wimberley and the Pedernales River in Johnson City. These gage readings are represented by the graphs above. The yellow triangles represent the median flow over an 80-year period and the blue line represents streamflow in CFS. More information about the Blanco and Pedernales River can be found by clicking the USGS symbol to the left of the name in the table above.

Jacob's Well Groundwater Management Zone Drought Management

In order to protect groundwater supplies and Jacob's Well spring flow in the 39 square mile Jacobs's Well Groundwater Management Zone, District Rule 15 designates cutback triggers based on Jacob's Well spring flow. When flows from Jacob's Well averages six cfs or less during any 10-day period, The District Board declares appropriate drought stage.
Discharge Flow Rate 30 Day Mean 10 Day Mean Alarm Trigger Critical Trigger Emergency Trigger
Jacob's Well Groundwater Management Zone
Jacobs Well Spg nr Wimberley, TX (08170990) as of 2021-07-28 5.37 4.57 6 5 3
Days with flow Above Stage Trigger 0 0 55
Days with flow Below Stage Trigger 16 6 0
Drought Stage
Jacob's Well Management Zone
Stage Start Date: June 2021

HTGCD Drought Stage History