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. Page Quicklinks:

July 2020 Hydro Report

These are dry times, and creeks and groundwater levels are starting to really show it. It’s been nearly two months since the last major rainfall (EAA gage reported 2.5″ on May 25th). Summers in Central Texas are typically dry and hot; this year is no exception.

Soils are drying out and smaller creeks have stopped flowing. Middle Trinity springs are sustaining flow in the Blanco River and Cypress Creek. Pleasant Valley and Park Springs’ flow is estimated by the USGS gage near Fisher Store Rd. Jacob’s Well flow is measured at the USGS gage at the Natural Area. Both springs show a steady decline since June 1st. At Jacob’s Well under these low-flow conditions, groundwater pumping can cause 1 to 1.5 cubic feet per second (cfs) fluctuation in flow throughout the day. This increased variation in Jacob’s Well springflow through time is shown in green hydrograph above.

Water levels in monitor wells show similar trends, though the decline is slightly delayed. Review of selected HTGCD monitor well data (from west to east) show that water level in the Burnett Ranch well began declining in early July, the Mt. Baldy well began declining in mid-July, and the Downing well shows decline since early June. Review of the BSEACD monitor wells shows the Edwards aquifer is behaving similarly. Water levels in the Hoskins and Lovelady wells began declining in early June.

To preserve our water resources, conservation is key–especially during these dry times. Outdoor landscape and lawn irrigation can account for up to 60% of household water use. During these dry summer months when springflow and groundwater levels are low, Please limit outdoor water use and if you do choose to water outdoors, do it in the early morning or late evening to limit evaporation. Native and drought-tolerant landscaping is paying off now–those plants are accustomed to hot, dry Texas summers. Keep an eye out for leaks, and use water wisely.

Annual rainfall average for Central Texas is approximately 33 inches per year.  Where that rain falls, how fast it falls, and how saturated the soils are when it does play a role in understanding recharge potential.  Key rain gages for the area are (upstream to downstream):

Realtime comparison of two key springflow 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
    • Springflow is a strong indicator of groundwater levels in the Jacob’s Well Groundwater Management Zone (JW GMZ), because low springflow directly correlates to low well water levels.
    • The 10-day average springflow 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.  Stream flow 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:

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