Spring rains in extreme South Texas have helped keep reservoir levels behind Amistad and Falcon dams from dropping, but more is needed to help crops and end the drought, according to various experts in the field.

“We’ve gotten a lot more rain this spring than we did last year, but crops still need to be irrigated,” said Dr. Juan Enciso, an irrigation engineer at the Texas AgriLife Research and Extension Center at Weslaco.

“Rains complement irrigation,” he said. “Sugarcane, for example, requires 60 to 70 inches of water. If we get our normal 25 inches of rain in a year, a grower still needs to irrigate almost 40 inches or so.”

Citrus requires about 43 to 50 inches of water, cotton 35 inches, sorghum 22 inches, vegetables 16 to 22 inches, and summer corn needs 25, he said.

“If rains fall at the right time, at germination for example, like they did this year, they can really help crop yields,” Enciso said. “It’s also very beneficial at flowering. Unfortunately, it often rains a lot in a short period of time, which can produce wasteful runoff.  Crops really need prolonged rain. And once a plant matures, more water won’t help yields.”

Rainfall totals in Weslaco so far this year amount to 6.8 inches, slightly higher than the 10-year average of five inches, Enciso said.

“We’re thankful for the rains, but we could use more slow, soaking rains to penetrate the subsoil profile and replenish our reservoirs,” Enciso said.

Barry Goldsmith, the warning coordination meteorologist at the National Weather Service in Brownsville, agrees.

Temporary relief

“The rains have provided a temporary relief, but long term, we’re just not there yet,” he said. “In fact, if we continue to have hot and dusty days, we’re in trouble.”

The wet spring weather pattern this year started in February, Goldsmith said, and even included a rare, severe hailstorm in McAllen that could eventually amount to damages of $100 million, according to the weather service website.

“The jet stream allowed energy to build up in February and that started things off. It gave us rains that made for a pretty spring; it gave a huge boost to plants and trees,” he said.

Sporadic rainfall through most of May in the Falcon and Amistad watershed, in both the U.S. and Mexico, helped growers and reservoir levels, according to Erasmo Yarrito Jr., Rio Grande watermaster with the Texas Commission on Environmental Quality.

“The rains didn’t raise reservoir levels, but they kept them from dropping,” he said. “Farmers were able to put off irrigating. We had lots of water-request cancellations at a time when we would normally be releasing huge amounts of water.”

Instead of releasing 100 cubic meters of water per second, Yarrito said releases have dropped to half that amount.

“Combined capacity of both reservoirs is at 56.86 percent, about normal for this time of year,” he said. “And even if we don’t get rainfall in the Mexican watershed, our reserves will carry us through this year and next year.”

Erasmo Valdez, a long-time corn and grain sorghum farmer in the mid-Valley area, said he is especially thankful for the rains that helped him save time and money.

“The rains bought me 14 or 15 days and helped me eliminate one irrigation, so far,” he said. “Last year at this time I had already irrigated four times and was thinking of the fifth because it was so hot and dry. I’m happy this year because I’ve only had to irrigate three times. That saves money and the rains help wash and re-energize the crops.”

What will future rainfall be? Goldsmith said he doesn’t have a crystal ball, but he knows what the area needs.

“What we need is what we call ‘efficient’ rains, a series of easterly waves of rain events from the tropics and sub-tropics,” he said. “Not more hail or a hurricane, which bring other hazards, but rather a pattern where we have rains in the morning, then again in the afternoon each day for about a week. Then a week of no rain, followed by more rain the following week. Periodic rains will get us out of this drought.”

According to the AgriLife Extension Agricultural Drought Task Force website (http://agrilife.tamu.edu/drought/), most of the Lower Rio Grande Valley is considered to be in a moderate drought. Only Starr County is listed as abnormally dry.

As to whether the weather “puzzle pieces” will fall into place to end the drought, Goldsmith said: “I can’t predict that. Are we now going back to the hot and dry conditions of last year and 2009? We just don’t know yet.”