MERCEDES, Texas (Border Report) — The United States is holding back water payments to Mexico in order to send a message, the U.S. International Boundary and Water Commissioner told Border Report.

“The first action that the State Department has done is in denying water deliveries to Mexico in the Tijuana area,” U.S. IBWC Commissioner Maria-Elena Giner told Border Report last week when she visited South Texas.

“We wanted to signal to them that our level of cooperation is diminishing because of the lack of performance on water deliveries. This is a first step,” Giner said.

Under a 1944 international treaty, Mexico is supposed to send 1.75 million acre-feet of water to the United States via the Rio Grande over five-year cycles. The current cycle ends in October and so far Mexico has paid less than 500,000 acre-feet of water — about a quarter of what it owes, according to IBWC data.

The United States, likewise, under the treaty is required to send to Mexico 1.5 million acre-feet of water from the Colorado River.

But Giner says requested deliveries to Tijuana, Mexico, south of San Diego, were not recently fulfilled. And she says more holding back of water, and other resources, could come next if Mexico fails to send the U.S. water.

“The State Department is evaluating all of its options that it has to leverage Mexico,” Giner told Border Report.

The stark action by the Trump administration is the first time in recent history that the United States has withheld water. And it comes after Agriculture Secretary Brooke Rollins visited the Rio Grande Valley on March 19 along with U.S. Sen. Ted Cruz, R-Texas, and U.S. Rep. Monica De La Cruz, R-Texas.

Their visits came as the region was reeling from months of drought and farm fields were drying up and crops dead after growers could not get water because of pumping restrictions placed on the dwindling Rio Grande.

The state’s only sugar mill in Santa Rosa shut down last year and Hidalgo County declared a water emergency.

Rollins’ visit “was really helpful,” Giner said, “in elevating the profile of this issue. The more sync that we are with the federal agencies, the better.”

Last week, dozens of inches of rain fell on the Rio Grande Valley, causing widespread flooding. Unfortunately, the rains fell too far east to be stored in the region’s two reservoirs, Giner said.

Falcon Dam, in western Starr County, did receive 2 inches of rain from the weather event, which was a boost of about 11,000 acre-feet. Mexico received about 16,000 acre-feet in their reservoirs from the rains.

On Monday, Falcon Dam was at 13% capacity and Amistad Reservoir, near Del Rio, was at 16%, according to the Texas Water Development Board.

Giner came to South Texas to tour the flooded region and told a meeting of local leaders and irrigation and drainage officials that despite some recent relief of rain, that Mexico will still be pressured to pay the water debt it owes the United States.

“The Department of States is keeping real close tabs as far as water deliveries. They have asked Mexico to provide them with monthly delivery schedules as well as a plan for how they’re going to address any of the shortfalls. They’re also looking at what are the measures that they can take,” Giner told the group.

Instead of sending water to Tijuana, Giner says the United States has agreed to send about 2,000 acre-feet to Mexicali “so they can do some repairs on the Mexican side of their aqueduct,” she said.

Sandra Sanchez can be reached at SSanchez@BorderReport.com.