Edinburg, Texas, has a little over 50 ditches throughout the city with all subdivisions connecting into the ditches for drainage and a link to the county ditches. The drainage water from four nearby cities also runs through the city ditches, so all their drainage must flow through Edinburg before going out to the bay.

As Robert Valenzuela, Edinburg Public Works right-of-way and drainage manager, described, “All their water comes to us and drains to our ditches and then leads over to the bay. Our water heads out once their water is done.” This can create a serious flooding problem in periods of heavy rain.

“In the past, with a certain amount of downpour, many subdivisions were getting flooded,” Valenzuela explained. “Once county ditches received so much rain, their ditches were full and city ditches were full, and the water receded back into the subdivisions.” One issue the city faced with this flooding was the inability to be proactive in where to send crews for sandbags or de-watering efforts.

To better monitor where flooding is occurring and send in assistance once it has occurred, the city invested in two real-time hydrological systems. These systems were placed in two ditches that are known to be at high risk of flooding. Data is sent to the public works drainage department every five minutes and monitored for risk of flooding. Once the water in a ditch reaches a certain height, it is considered to be in danger of flooding or ponding, and the department can prepare crews for sandbags and de-watering operations as needed.

“We haven’t had a major rain event to see if these new systems do work 100% yet,” Valenzuela admitted. “We have had rain events, so we know the updating of data has continued to work. We get accurate information but have not fully tested it out. We would need a heavy downpour of about one hour in order to test the flooding proactivity for the systems.”

These systems give the city the height level of the ditch, temperature, volume of water in the ditch and air direction. “It’s all to let us know what the water is doing and where it’s going.”

A stormwater task force affiliated with the city, the International Boundary and Water Commission, which also is in charge of the release of water from Mexico, helped the city apply for the grant to purchase these hydrological systems. The task force asked the city what type of funding would be most beneficial for them. Each system cost approximately $15,000, and it was a matching grant. Therefore, the city purchased one hydrological system and then the grant money purchased the second system. The process took approximately eight months. The city wrote a letter of support in order to receive the grant money and purchased one system. Man hours for maintenance systems were also donated from the city as part of the grant process. After it was approved and purchased, installation of the systems took approximately one week.

System installation involved removing all the water from each of the two drainage ditches and putting a probe in the middle of the ditch closest to the outfall. All the components, such as Wi-Fi antennas, necessary to send information from the probe to city computers are outside, 20 to 30 feet up on the top of the ditch.

These hydrological systems came from a nonprofit, which has previously focused on water sampling and testing the Hudson River in New York. This nonprofit, Research Applied Technology Education and Services, opened a branch in Texas and works with the stormwater task force. RATES gives students the opportunity to work with different components to create systems, such as the hydrological system, that will work when applied to real city problems.

In June 2023, the city of Edinburg was recognized at the Texas chapter of the American Public Works Association conference in Waco. The city was nominated to recognize its efforts to be proactive in its flood management practices. Valenzuela stated it was an honor to win while going up against so many municipalities throughout the state.

The goal is to continue to add more of these real-time hydrological systems into each of the ditches throughout the city as it and the department’s budgets allow.

“Procedure-wise we have city standards with the engineering department on new subdivisions coming in with how much runoff must be kept on a property and in retention ponds before getting discharged into the system,” Valenzuela commented. “When we receive a lot of rain, it floods throughout the whole valley. There are many instances to mitigate or prepare for flooding, and it helps to be prepared, especially during the heavy rainfall seasons of June and July and hurricane season.”

Besides engineering policies, these new systems are the only flood management currently in place in Edinburg.

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