Frequent thunderstorms this season have left the lake at a level that supports recreation and should sustain the water needs of North Texas.
Mark Fox, a warning and coordination meteorologist with the National Weather Service, said June and July have been very wet months for DFW, but it’s not too unusual.
“It’s normal in an abnormal way,” he said.
He explained that historically, May is typically DFW’s wettest month with an average of 5 inches of rain, and this year there was only .7 inches of rain recorded.
“Now that is very unusual,” Fox said. “We made up for it in June. In June, we normally get 3.75 inches of rain, but we had almost 8.5 [inches], so we made up for normal.” Fox said it was the fifth highest rainfall for June in the record books.
Fox said heavy rains on June 19, 23, 24 and 27 replenished the lake even with the previous month’s lack of precipitation.
The first part of July has been very wet too, he said.
“Normally for the entire month we get 2 inches of rain. So far, for the first eight days, we saw 2.75 [inches] of rain,” Fox said. “We could go the remainder of the month without a drop of rain and that’s pretty much normal for July.”
Fox explained that much of the rainfall the area has received this season is from ‘air mass thunderstorms’ that hit in the late afternoon and early evening.
“As the afternoon air heats up a lot, you start to get rising air just because the conduction currents that are formed. Thunderstorms develop in late afternoon and rain themselves out. By the time the sun sets, the heating gets cut off and then the storms go away,” Fox said. “It’s kind of a late afternoon typical summer thunderstorm.”
All this precipitation is good news for Lewisville Lake. The lake’s conservation pool is currently at 100 percent capacity with an additional 2 percent in the flood pool, according to the U.S. Army Corps of Engineers, who manage the lake.
The lake level was at 522.29 feet as of Friday afternoon and the Corps is releasing 297.0 cubic feet of water per second through the dam’s outlet works, which is normal for this time of year.
This time during the summer, an annual algal bloom can alter the taste and odor of the lake water, which is the primary source of drinking water for Lewisville residents. The taste and odor is temporary and harmless. Lewisville increases the use of activated carbon in the water treatment process during the summer to help with taste and smell.