There are several key players when it comes to water monitoring in the Hill Country.  Each agency publishes data through different platforms and reports.  This page compiles useful references that can help get a more comprehensive view of water resources in the Hill Country.

Recent Rains Lead to Some Flow at Jacob’s Well
October 2022 Hydro Report

After 32 days of zero flow this year, Jacob’s Well finally started flowing again! With a total of about 3/4 of an inch of rain this week, a little recharge and less groundwater pumping goes a long way! It’s a happy thing to see, but springflow is less than 0.5 cfs and will likely subside quickly without more rain. Link:  Real-time data from the USGS Jacob’s Well gauge.

We won’t see recovery in aquifer storage, spring flow, or creek flow without rain.  Looking at the US Climate Data historic monthly average rainfall totals for Blanco, by the end of October there are usually 29.7 inches of rain.  As of October 28, the weather station at the Watershed Association near Jacob’s Well has recorded a scant 12.75 inches of actual rainfall.  The Wimberley Valley area is about 16.9 inches below the average rainfall for this time of year, which impacts aquifers, springs, creeks, and rivers. Please keep conserving water! 

Monitor wells are at record lows, and many well owners are having to rely on hauled water.

Drought recovery will require over 17 inches of rain over the contributing and recharge zones of the Trinity Aquifers.  The prolonged hot and dry conditions have affected soil moisture, groundwater storage in aquifers, and flow from springs and creeks, which all have different response times to rainfall. Dry soils will likely soak up the first inch or two to the benefit of trees, grasses, and plants. After soils are saturated, they’ll allow runoff to fill creeks and rivers, which funnel water into the groundwater system through karst features like caves, fractures, and sinkholes. Water levels in the Middle Trinity Aquifer in western Hays County will recover more quickly than the Lower Trinity Aquifer, which is deeper and has a confining layer that generally separates the two aquifers. Once water levels in the Middle Trinity Aquifer rise above spring elevations, spring flow will increase and supply needed baseflow to boost flow in streams like Cypress Creek and the Blanco River. Once Jacob’s Well reaches a 10-day average above 6 cubic feet per second, the Hays Trinity Groundwater Conservation District will remove the drought declaration.

Please continue to conserve. Coordinated water conservation is key to preserve groundwater availability, spring flow, and water supplies.  All of the Hill Country is experiencing rainfall deficits which leading to pronounced drought conditions in our area.

Most communities in the Hill Country are groundwater-dependent, so drought conditions are particularly troublesome for water supplies, recreation-based tourism, and springs and rivers.  Please follow groundwater district drought restrictions and local water provider drought water use guidance.  Limit outdoor irrigation and conserve water indoors.  Identify and fix leaks.  Conserve water to prolong water supplies until rainfall can replenish our aquifers. While we can’t control the weather, we can conserve water and look for innovative ways to use alternate supplies (like site-harvested supplies—rainwater and AC condensate) to lessen impacts of pumping. While each aquifer behaves differently, all groundwater is limited and deserves to be used wisely. For more information on native landscapes, rainwater harvesting, leak identification tips and more, visit the Home Owner Resource page.

No matter what area agencies call their drought declaration, coordinated water conservation is important to preserve groundwater availability, spring flow, and water supplies.

Agency Drought Stage Date Declared Details
Barton Springs Edwards Aquifer CD Stage III Critical Drought (minimum of 30% Reduction) Oct 2022 Press Release, 10/20/2022
Blanco Pedernales GCD Stage 3 – 20-50% Reduction in pumping August 2022 Press Release, August 2022
Comal Trinity GCD
Cow Creek GCD Stage 3 – 30% Reduction in pumpage June 2022 Public Notice, 6/14/2022
Hays Trinity GCD 30% Curtailment for Jacob’s Well GMZ, 40% for remainder of the District July 2022 Board Order, 7/31/22
Edwards Aquifer Authority San Antonio Pool is in Stage 3 – 35% Reduction June 2022 Press Release, 6/13/22

[Updated 10/28/2022]

Annual rainfall average for Central Texas is approximately 33 inches per year.  To understand recharge potential, it’s important to track where rain falls, how fast it falls, and how saturated the soils are.  Key rain gages for the area are (upstream to downstream):

Realtime comparison of two key spring flow sites: (USGS gages: Blanco at Fischer Store–08170950 and Jacob’s Well–08170990)

Jacob’s Well Spring, Cypress Creek

Jacob’s Well is a Middle Trinity Aquifer spring that provides the baseflow for Cypress Creek.

    • Realtime data: USGS 08170990 Jacobs Well Spg nr Wimberley, TX
    • Spring flow is a strong indicator of groundwater levels in the Jacob’s Well Groundwater Management Zone (JW GMZ), because low spring flow directly correlates to low well water levels.
    • The 10-day average spring flow is a drought trigger for the HTGCD Jacob’s Well GMZ (Thresholds:  10% Curtailment: below 6 cfs; 20% Curtailment: below 5 cfs; 30% Curtailment: below 3 cfs).
    • Groundwater pumping causes 1 to 1.5 cfs fluctuation in flow and is more evident under low flow conditions.

Pleasant Valley and Park Spring, Blanco River

Pleasant Valley and Park Springs are Middle Trinity Aquifer springs that provide significant baseflow for the Blanco River, especially during dry periods.

The Hill Country’s iconic streams are known for their clear water and rocky bottoms.  Oftentimes, cracks, caves, and faults are visible in stream beds.  When creeks and rivers are flowing, these cracks, caves, and faults channel water from the surface into the groundwater system below.  Streamflow gages are strategically located to help monitor gaining (where springs are found) and losing (where recharge happens) sections of creeks and rivers. Key gages include:

Groundwater monitoring is an art.  TWDB, HTGCD, and BSEACD have extensive monitoring networks.

Key wells from west to east:

Archived Hydro Reports

Month   Cypress Creek – Jacob’s Well Blanco River – Pleasant Valley & Park Springs Date Published
2022 Sept What does Drought Recovery Look Like? 9/13/22
2022 June Wide-spread Drought 6/16/2022
2022 April Drought Conditions Return 4/4/2022
2022 Feb Three-month Dry Spell Ends with Icy Precipitation 5.7 cfs 16.4 cfs 2/3/2022
2021 Nov Rain brings increases in spring flow and groundwater levels 19.2 cfs 22.5 cfs 11/14/21
2021 Oct Rain brings temporary increases in spring flow and groundwater levels 2.7 cfs 16.0 cfs 10/7/21
2021 Sept Water levels and spring flow on the decline (again) 2.6 cfs 28.1 cfs 9/16/2021
2021 July Spring flow increased, Groundwater levels still low 3.9 cfs 33.2 cfs 7/6/2021
2021 May Recharge! 2.2 cfs 13.5 cfs 5/18/2021
2021 April Lowest Groundwater Level Recorded Since 2005 1.4 cfs 11.4 cfs 4/22/2021
2021 March 2.4 cfs 13.5 cfs 3/10/2021
2021 January 0.3 cfs 11.8 cfs 1/19/2021
2020 December 1.3 cfs 16.8 cfs 12/8/2020
2020 November 1.1 cfs 17.1 cfs 11/11/2020
2020 October 1.7 cfs 17.7 cfs 10/25/2020
2020 September 6.5 cfs 25.2 cfs 9/14/2020

Please note:  Page under construction.  Please email robingary@wimberleywatershed.org with suggestions or questions.