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Water + Weather for August 2023 Posted on September 10, 2023


Andrew Weinberg – Geoscientist, Texas Water Development Board

Hi everyone, and welcome to the Texas Water Development Board's Water and Weather report. I'm Andrew Weinberg, a geoscientist in the groundwater division sitting in for Dr. Mark Wentzel. And today, we'll be looking at conditions in our state at the end of August 2023 and focusing on groundwater conditions. Let's take a look at some of the big water and weather headlines.

This August was the hottest and fourth driest August for our state in data going back to 1895. At the end of August, 76 percent of the state was in drought, up 27 percentage points since the end of July. Statewide, storage in our water supply reservoirs is about 69 percent of capacity, more than 13 percentage points below normal for the time of year. Groundwater is likewise showing the effects of drought, with many districts imposing restrictions on pumping and water use. 

Let's take a closer look at temperature and precipitation. On these maps, we're looking at temperature and precipitation relative to what is considered normal for August. From a water supply perspective, reds, oranges, and yellows mean trouble on both maps. They show areas with above-average temperatures on the left and below-average precipitation on the right. As you can see, August was pretty rough. In fact, 2023 was the hottest August for the state going back to 1895. Thanks to remnants of Tropical Storm Harold, some parts of South Texas did receive near- to above-normal rainfall, but 2023 was still the fourth driest August in the historical record.

Let's take a closer look at drought conditions at the end of August. This is the drought monitor map for conditions as of August 29. On this map, 76 percent of the state is in drought­—the tan, orange, and red colors—up 27 percentage points from the end of July. This is the largest extent of drought in our state since the end of August 2022, when a similar amount of the state was in drought. Central Texas has been hit especially hard, and some counties have been in exceptional drought for much of the summer. We'll take a look at how this is affecting groundwater in a minute. 

Let's take a closer look at groundwater conditions in Hays County in the Hill Country in Central Texas. Groundwater conditions vary a lot locally, depending on what aquifer a well is in, how much pumping is going on, where the well is located in relation to areas of recharge or discharge, and whether or not we're in a drought. As a hydrogeologist, I spend a lot of time looking at hydrographs, or records of water level over time, trying to sort these factors out. We're looking at water level records for three wells in Hays County between Dripping Springs and Wimberley. The different colors represent different wells, and the traces show how the water levels have changed over time. These three wells are in the Middle Trinity, which is the main source of groundwater supply in Hays County. The Middle Trinity recharges rapidly during wet periods, but prolonged drought and increased pumping associated with rapid growth in the area has drawn down water levels between Dripping Springs and Wimberley at between 20 and 30 feet per year since 2019, bringing current water levels below the previous lows from the 2011-2014 drought. With the plummeting groundwater levels, Jacob's Well has ceased flow, and the Hays Trinity Groundwater Conservation District is at stage four water restrictions, representing a 40 percent curtailment in water use. As the district states, water wells are failing at an unprecedented rate. No new permits for production or nonexempt well construction will be issued until conditions improve. Similar water use restrictions are in place for most of the groundwater districts across the Central Texas area. 

Hot and dry conditions have also had an impact on our surface water reservoirs. The dark line on this chart shows how storage in our water supply reservoirs this year compares to minimum, maximum, and median values for the day of the year from data going back to 1990. Also displayed are lighter lines that show how we did in 2022 and 2021 and a red line that shows how we did in 2011. At the end of August, supplies are at 69 percent of capacity, 13 percentage points lower than normal for this time of year. That's almost two percentage points lower than last year but still about four-and-a-half percentage points more than during 2011.

What can we expect over the next few months? Here's the latest seasonal drought outlook from the National Weather Service. Hotter and drier-than-normal conditions that plagued Texas this summer are expected to persist into the early fall, leading to drought persistence throughout the state and drought expansion in the Panhandle through the end of November. On a longer time frame, the outlook is better for Texas. El Niño conditions, warmer-than-average sea surface temperatures in the eastern equatorial Pacific, are in place and expected to persist into next year. El Niño typically brings Texas wetter and cooler-than-normal conditions during fall and winter, which should hopefully bring widespread drought relief to our state before the end of the year.

If you'd like to know more about water conditions in Texas, check out the Water Development Board's Water Data for Texas website. That concludes our report for August 2023. For the Texas Water Development Board, this is Andrew Weinberg signing off.

This article is posted in Aquifers / Weather / Drought / Water Supply / Groundwater / Water Data .