In late March 2025, the city of Mercedes received over 20 inches in less than 24 hours as recent drainage improvements were put to the test.

Local residents have long known what such intense rains can do to a city. In June 2018, over 15 inches of rain fell over the city’s downtown and adjacent areas and caused widespread flooding. The preceding year– again in June – a similar rain event occurred in Mercedes and also inflicted heavy damages. Firefighters were called upon in helping local residents evacuate their waterlogged homes.

Alberto Perez was not the Mercedes city manager in those years. He knew of the flooding and as a city manager in another Rio Grande Valley city before coming to Mercedes was well aware that drainage and flooding issues rank among the top concerns of local residents.

“My focus has been on drainage improvements since I got here,” said Perez, who arrived in Mercedes in 2021. “We can’t grow and bring in new businesses if we’re flooding.”

The March rains of this year were torrential and affected other area communities, including neighboring Weslaco. In Mercedes, there was, of course, some flooding as there would be anywhere given the volume of rain. The difference from the heavy rains of seven years prior is that it took less than three days to clear flooded areas versus the weeks needed in 2018 to do the same.

“It gives you an idea that they’re working,” Perez said of the drainage improvements made since 2018. “I’d still like to be further along. I know there’s still a lot of work to be done.”

‘We’re Not Done’

The flooding episodes of 2017 and 2018 resulted in a$190 million bond being put out for consideration as part of the November 2018elections cycle in Hidalgo County.

Voters approved the bond. It is leading to improvements in widening and deepening drainage ditches, improving and installing culverts and constructing detention ponds to better retain and manage storm waters. For Mercedes, the city and immediate areas received about $20 million of the $190 million bond. Some of those improvements are still under construction, but there was enough work completed to help move the volume of water that fell in the March2025 rain event.

“It’s about moving the water more quickly so it’s not sitting in the streets,” Perez said.

At the present time, there are three 2018 county bond projects nearly completion in the Mercedes area. None of them were factors in dealing with the March rains of this year since those projects were still under construction at the time.

One of them is the Anaquita Drain Section 1 ditch project that focuses on taking waters from areas along Business 83 and diverting them south to the Arroyo Colorado. This project is nearly complete. A second Anaquita project impacts the area between Dawson Road and Mile 1 East that is north of Expressway 83. This part of the project is 85 percent complete and includes channel and culvert improvements in taking floodwaters to the Arroyo. A third Anaquita project starts at Baseline Road in north Mercedes and will make additional channel and culvert improvements.

The construction costs of those three country projects for the Mercedes area are nearly $5 million. A fourth drainage project that is ongoing is a city effort. Over $3 million is being spent to make improvements in piping capacity and sewage connections in what the city is calling the Capisallo Terrace project on the eastside of Mercedes. Taken all together, the four projects will help Perez and the city government he oversees make infrastructure improvements all residents want to see.

“I’ve always said there’s no sense in repairing streets if we can’t move water,” he said. “We need to fix drainage first or we’ll be wasting money on streets. We’re moving in the right direction, but we’re not done.”

Ric Cavazos