Jump to main content

Water + Weather for June 2021 Posted on July 13, 2021


Dr. Mark Wentzel – Hydrologist, Texas Water Development Board   

Hi everyone, and welcome to the Texas Water Development Board's latest Water and Weather report. I'm Dr. Mark Wentzel, a hydrologist here in the Surface Water Division at the agency. And today, we'll be taking a look at our state's hardworking water supply reservoirs.

Our surface water supply reservoirs were built to even out the amount of water available to meet our needs throughout the year. They build up storage when water is plentiful and supplement supplies when water is scarce. To see how our water supply reservoirs have been doing their job over the last several months, let's look at a chart of storage across the state as a percentage of total conservation capacity. The dark line on this chart shows how storage 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 2020 and 2019. From October 2020 to March 2021, a six-month period, Texas received seven and three-quarter inches of precipitation averaged across the state, more than three inches less than normal for that period.

Our water supply reservoirs began 2021 at about 82 percent of conservation capacity. And because of the dry conditions, remained at that level through the end of March. That's more than three percentage points less than normal for that time of year. Fortunately for us, April, May, and June are typically wetter months for Texas. And May 2021 didn't disappoint. It was the fifth wettest May for Texas in National Weather Service data going back to 1895. We averaged more than six inches of rainfall across the state, almost three inches more than normal. Our water supply reservoirs took advantage of that abundant rainfall to increase their storage to 85 percent of capacity by early June, right about average for that time of year.

What can we expect going forward? July and August are typically hot and dry for most of our state. During that time, our water supply reservoirs will provide additional water to meet our needs, gradually drawing down their volume. In a typical year, volume in our water supply reservoirs will decline to about 80 percent of capacity by the end of September. Over the fall, winter, and next spring, they'll regain their volume to meet our needs for the next summer.

As you enjoy your summer and possibly take some time off from work, remember that our water supply reservoirs are hard at work for you. Visit our website, twdb.texas.gov, and click on the conservation tab for some ideas on how to make our reservoirs jobs a little easier. That concludes our Water and Weather report for June 2021. Until next time, I hope you all stay healthy and safe.  

This article is posted in Weather / Drought .