outlook+water: Massive rains in the Hill Country, drought improvement, but the Edwards is still in drought

SUMMARY:

• Drought conditions (D1–D4) decreased to 30% of the state from 39% of the state four weeks ago (and is surely lower after the early July rain bombs); statewide reservoir storage increased to 80% full up from 78% four weeks ago, about 4 percentage points below normal for this time of year.
• The El Niño Southern Oscillation remains in neutral conditions, which are favored through March.
• The recent rains in the Hill Country are not as rare as you might think.

I wrote this article on August 8, 2025

The July rainfalls will be remembered for many, many years. The storms took at least 135 lives, including 117 in Kerr County, 9 in Travis County, 5 in Burnet County, 3 in Williamson County, and 1 in Tom Green County. Three-hour rainfall rates exceeded one in 1,000-year events upstream of Hunt, north of San Angelo, and south of Bertram (Figure 1a). One in 500-year events occurred in those places, but also in and near Menard and Burnet (Figure 1a). Twenty-four-hour rainfall totals exceeded one in 1,000-year events in San Angelo and between Menard and Mason (Figure 1b). 

While the storms nearly filled Lake Buchanan and Lake Travis, Canyon Lake remains well below full even though it received a welcome increase in storage from 46% full to 69% (Figure 1c). Canyon Lake remains about 25 percentage points below normal for this time of year. Medina Lake saw little improvement, eeking up to 6.4% full from 2% full before the storms (Figure 1d). The lake remains about 60 percentage points below normal for this time of year. Little water made it down the Nueces River to benefit the Choke Canyon Reservoir. Choke Canyon is still about 13% full and almost 40 percentage points below normal (Figure 1e). The reservoir remains in record-low conditions.

The Edwards Aquifer didn’t benefit as much from the rains as you might think. One reason is that the Guadalupe River doesn’t provide much recharge to the Edwards Aquifer; it needs to rain west of San Antonio to induce improvements in the San Antonio Segment of the Edwards Aquifer. The Barton Springs Segment needs more local rain, especially in the Onion Creek watershed. As a result, both aquifers remain in drought conditions, although both have seen some improvement.

July precipitation provided a giant purple blob in the middle of the state, with two dozen counties receiving more than 10 inches of rain, about a dozen counties seeing more than 15 inches of rain, and a few counties with parts seeing more than 20 inches of rain (Figure 2a). A large part of the state received more than normal rainfall, while a sizable part of the state saw more than six times normal rainfall (Figure 2b). Outside of the flood zone, much of the state received less than half of normal rainfall in July (Figure 2b).

The amount of the state under drought conditions (D1–D4) decreased from 30% four weeks ago to 19% today (Figure 3a), with improvements in the southwestern third of the state (Figure 3b). Extreme drought or worse decreased from 13% of the state four weeks ago to 4% today, with exceptional drought decreasing from 6% to 0.5% (Figure 3a). In all, 28% of the state is abnormally dry or worse (D0–D4; Figure 3a), down from 38% four weeks ago.

The North American Drought Monitor, which runs a month behind current conditions, shows drought in the American Southwest with smatterings in the northern part of the continent (Figure 4a). The Rio Conchos basin in Mexico, which confluences with the Rio Grande just above Presidio and hosts the largest tributary to the Lower Rio Grande, remains in extreme to exceptional drought (Figure 4a).

Conservation storage in Elephant Butte Reservoir—an important source of water for the El Paso area—decreased from 6.0% full four weeks ago to 3.8% more recently (Figure 4b), about 20 percentage points below a rather pitiful median storage of 22% full. Current levels in the reservoir are flirting with lows not seen in at least 35 years. 

Combined conservation storage in the Amistad and Falcon reservoirs increased to 25.6% full from 23.7% four weeks ago and is about 20 percentage points below normal for this time of year (Figure 4c). Storage is on an increasing trend from recent rainfalls, so perhaps we’ll see more storage improvements over the next month.

Basins across the state continue to host flows over the past week that are below the historical 25^th, 10^th, and 5^th percentiles (Figure 5a). Statewide reservoir storage is at 78.7% full, down (believe it or not!) from 79.5% four weeks ago and about 4 percentage points below normal for this time of year (Figure 5b). The reservoir marked in reddish-orange in the Dallas-Fort Worth area (the persimmon in a sea of blueberries) is New Terrell City Lake and has dropped from full in early March 2024 (Figure 5c). The Lake is no longer used for water supply and appears to be undergoing long-term maintenance work.

My (drumroll please) “Hydrograph of the Month” is Lake Buchanan for how quickly it came up following the July rains (Figure 5d).

We are under La Nada conditions, with neither an El Niño nor a La Niña imminent (Figure 6a). Neutral conditions are favored through the end of this year and into 2026 by both the dynamical and statistical models (Figure 6a, b).

The U.S. Seasonal Drought Outlook through August shows drought persistence in South Central Texas and along the Rio Grande (Figure 7a). The three-month temperature outlook projects—surprise, surprise—above-average temperatures for most of the state (Figure 7b), while the three-month precipitation outlook favors average rainfall (Figure 7c).