The rains received across West Texas last week resulted in major inflows to the area’s reservoirs, and an overall improvement to the drought conditions threatening the region.
Storms on April 20, which delivered less-than an inch of rain to several spots around San Angelo, went on to drop as much as 8 inches in the northeast part of the state, after producing large hail and tornadoes in Irion, Sterling and Tom Green counties.
An estimated rainfall rate of around 1.5-inches-per-hour fell in the Middle Concho watershed for a sustained period, and by April 21 storm waters in that channel reached the 12-Mile Bridge on US Highway 67 South, and began flowing into Twin Buttes Reservoir, which caught the most significant storm flows, adding 11,038 acre-feet, or 3.6 billion gallons.
What a Difference Some Rain Makes
All told, San Angelo area reservoirs added 19,685 acre-feet to their holdings, or 6.4 billion gallons. To put that in perspective, the average daily water usage for San Angelo is about 12.5 million gallons, or 36.82 acre-feet, so 19,685 acre-feet would be enough water to serve San Angelo for about 535 days.
With all of the catch pockets in the Middle Concho Watershed full, further rains forecast for that watershed this week would be likely to make it all the way Twin Buttes.
Reservoirs get a boost
Biggest Gains
- Twin Buttes Res. – added 11,038 acre-feet
- Ivey Res. – added 3,402 ac.-ft.
- O.C. Fisher Res. – added 2,643 ac.-ft.
- Lake Nasworthy – added 508 acre-feet
- Lake E.V. Spence – added 570 ac.-ft.
Almanac
So far this year, the official rainfall total for San Angelo is 3.79 inches.
Normal rainfall for this date is 4.66 inches.
The most rain San Angelo ever received in April was 6.54 inches in 1908.
The lowest amount of rainfall recorded in April was 0.0 inches in 1920 and 1998.
Lake Levels
Before the rains: April 16
Reservoir – % – total volume – increase/decrease
- Lake Nasworthy – 91.9% with 9,326 ac.-ft.
- Twin Buttes Res. – 6.8% with 21,292 ac.-ft.
- Ivey Res. – 38.8% with 215,304 ac.-ft.
- Lake E.V. Spence – 15.7% with 81,412 ac.-ft.
- O.C. Fisher Res. – 7.3% with 8,466 ac.-ft.
After the rains: April 23
- Lake Nasworthy – 92% with 9,339 ac.-ft. / 13
- Twin Buttes Res. – 18% with 32,330 ac.-ft. / +11,038
- Ivey Res. – 40% with 220,000 ac.-ft. / +4,696
- Lake E.V. Spence – 16% with 82,480 ac.-ft. / +1,059
- O.C. Fisher Res. – 9% with 11,345 ac.-ft. / +2,879
Water Conservation in San Angelo
San Angelo currently is in standard conservation, with outside watering restricted to no more than 1-inch, twice-per-week. Watering is prohibited between noon and 6 p.m. and runoff of more than 150-ft. is always prohibited.
Hand watering of lawns, gardens, landscape areas, trees, shrubs or other plants being grown outdoors or foundations may be done on any day, except during the prohibited watering hours of noon to 6 p.m., provided the allowable application rate is not exceeded.
To report watering violations or leaks call 325-657-4409.
