In a turn of events that has brought both relief and caution, recent flooding in South Texas has caused a substantial rise in the water levels of two critical reservoirs that supply Corpus christi. The city, which has been grappling with severe water shortages, is now watching closely to see if this influx will alleviate its drought conditions or merely provide temporary respite.

The reservoirs in question, Choke Canyon and Lake Corpus Christi, have seen notable increases in their water levels following the heavy rains that swept through Central and South Texas last week. These storms, which triggered flash flood emergencies and necessitated evacuations and rescues, have also brought a glimmer of hope to the drought-stricken region.

Choke Canyon Reservoir: A Significant Boost

The most dramatic changes have been observed at Choke Canyon Reservoir, the city’s largest water resource. According to data from the Meadows Center for Water and the Environment at Texas State University the reservoir’s water level climbed from 7.9% of capacity on Monday to 19.8% by Saturday. This is a substantial increase, although the reservoir was last consistently full in the early 2000s and has been below 50% full since 2013.

Robert Mace executive director of the Meadows Center, emphasized the significance of this rise. “It’s nothing to sneeze at,” he said, noting that the reservoirs are still rising, indicating that more water is on the way. Even if the levels were to stabilize today, this influx would buy Corpus Christi valuable time to pursue alternative water supplies.

The Journey of the Water: From Rivers to Reservoirs

The water that is now filling Choke Canyon Reservoir originates from the Frio, Atascosa, and Nueces River systems. The Frio River, which flows into Choke Canyon, rose from a depth of around one foot in recent weeks to nearly 30 feet on July 22 in Tilden. At its peak, the river carried roughly 20,000 cubic feet of water per second.

Greg Waller a hydrologist with the National Weather Service’s West Gulf River Forecast Center provided insights into the forecast. He predicts that Choke Canyon Reservoir could rise a total of 12 feet, bringing it up to 192 feet. Currently, the lake is nearing 186 feet, which, while an improvement, is still far from full.

The Complexity of Predicting Lake Corpus Christi’s Inflows

While Choke Canyon Reservoir is already receiving inflows, Lake Corpus Christi is expected to begin seeing them within the next week. However, forecasting these flows is more complicated due to the Nueces River’s interaction with the Edwards Aquifer Recharge Zone. During dry periods, the ground can absorb water before it reaches the reservoir, making it difficult to predict how much water will actually make it to Lake Corpus Christi.

Waller noted that the last five rain events have shown “variable loss” of water, and while some water will likely recharge the aquifer this time, it’s too early to calculate how much. The Nueces River in Cotulla crested at significant flood levels at 29 feet on July 22, up from 4 feet in the weeks prior. This water will continue to travel downstream in the coming days, with forecasters expecting it to arrive at Lake Corpus Christi, which currently sits at 32% capacity, as early as July 27.

Corpus Christi’s Response and Future Outlook

Corpus Christi officials are closely monitoring upstream river flows to both Choke Canyon and Lake Corpus Christi. Nick Winkelmann chief operating officer of Corpus Christi Water, stated that their team is continuously tracking upstream gauge levels and coordination efforts across the watershed. The city is fully prepared to manage incoming volumes to ensure dam safety, optimize municipal supply storage, and fulfill all regulatory requirements.

The city plans to hold a meeting next week to discuss what the rising lakes mean for its water emergency. However, experts caution against declaring victory too soon. Mace noted that Texas is a state of drought with occasional massive flooding, and it remains to be seen how much water will ultimately enter these reservoirs and whether they will be true “drought busters” for Corpus Christi.