Editor’s Note: The following is an article on flooding problems submitted by Ned Sheats who has been researching flooding issues since 2008. This is his second article that is the result of research, interviews with city and county officials and his own opinions on what he’s learned.
In January, the Progress Times published “Why does the Rio Grande flood?” In the article, it became clear there were at least two separate complex and interwoven topics. One is the overloading of Mission and Hidalgo County drainage systems, creating localized flooding, as the result of heavy thunderstorms; the other is flooding of the Rio Grande from hurricanes and tropical storms hitting the Mexican watershed. Runoff from Mexican cities like Monterrey is delivered either into Falcon Lake or the river via the San Juan River near Rio Grande City. Both issues are constant and serious threats to the safety of the community, not to mention detriments to further development here. They are also issues that no single agency can cure.
In 2008, the policy for both the City of Mission and the county drainage district was that only a limited amount of water could be directed south to the existing floodway. At the time Hidalgo County Drainage District #1 (HCDD) officials interviewed explained it was due to rules from the U.S. International Boundary and Water Commission (IBWC), the agency that is charged with regulating the flows of water for American and Mexican floodways.
However, this seems to have been a misconception or misunderstanding. Recently, Rodolfo Montero, operations manager for the Lower Rio Grande Flood Control Project for the IBWC, explained that although there are some rules during a major flood event, adding water to the floodway when the system is not overloaded is not restricted.
When there is river flooding similar to that experienced after Hurricane Alex last summer, the floodways carry large volumes of water to prevent river flooding of cities downstream from Mission. Under these extreme conditions the gates to the floodway, which normally would be open to allow local floodwaters to flow into the floodway, are closed. Even under these conditions, the county drainage district is allowed to pump flood water into the floodway as long as the levees can safely handle the load, according to Montero. Local city and county officials now concur that to significantly reduce flooding more water must go south to the floodway.
Godfrey Garza Jr., the director of HCDD, who for years has promoted the construction of the new Raymondville Drain, running from Edinburg to the Laguna Madre, now says that its completion, depending on funding, environmental studies, and other legal issues, is from five to 15 years in the future. This project is key to improving the drainage for all of Hidalgo County north of Business 83, as this area naturally flows east toward the Laguna Madre, not south to the river. The undertaking, which has been delayed, has had only preliminary environmental studies completed.
Since the Raymondville Drain is at least half a decade from completion, Mission and McAllen have taken the lead in solving the thunderstorm related problems.
Mission had budgeted and has completed projects totaling nearly one million dollars under Stewart Road and near Conway Avenue to direct additional run-off south by adding capacity to an existing route and redirecting some flow that would have ended up in the overloaded Mission Lateral. This drain, whose channel runs between Griffin Parkway and 2 Mile Line Road from La Homa Road to Bentsen Road in McAllen, drains a large portion of Mission from Business 83 north to Palmhurst. Its insufficient capacity has been responsible for flooding three times since 2008. Also, Mission Mayor Norberto “Beto” Salinas sent a letter in March to Hidalgo County Precinct 3 Commissioner Joe M. Flores in which he proposes widening the Mission Lateral to provide more temporary water detention and increasing the southern flow in areas along Conway Avenue, south of Business 83.
McAllen, which is undertaking the widening of Bentsen Road, is also expanding the Mission-McAllen Lateral in that same area. That ditch drains the Mission Lateral and their positioning of three new culverts under the Edinburg Canal, will more than double the flow through the Rado Drain to the Mission Inlet then to the floodway. These two actions, when completed, while not solving the problem of the needed Raymondville Drain, will do much to minimize the current over capacity problem with the Mission Lateral.
Currently, there is a disagreement between the cities and county on how many storm sewer pipes are actually under Pecan Boulevard McAllen officials said there are two pipes, but the county says their documentation shows only one. At this date, that decision is left in the political and engineering arenas and will ultimately decide our safety. Once the amount of increased flow is decided, the county will also have to increase the size of the gates at the junction of the Mission Inlet and Main Floodway so as not to flood those areas south of the expressway and north of the Main Floodway.
Hurricanes & Tropical Storms
Last summer, extensive flooding occurred along the Rio Grande River after Hurricane Alex and Tropical Depression No. 2 dumped large amounts of water in the Mexican watershed upstream. The river flooding left many areas along the river under several feet of water, including the southern part of La Joya and Havana. South of the Mission levee the Riverside Club, Pepe’s on the River and Chimney Park RV Resort were all flooded, as were Anzalduas Park and Bentsen State Park, causing significant damages. An even greater threat of flooding was narrowly averted when emergency crews worked around the clock to prevent the levee at the Peñitas pump station from collapsing. Officials predicted at the time that a significant portion of Mission, including Cimarron, could have been flooded if the levee had given way.
While the threat of tropical storms and hurricanes still leaves areas of Mission vulnerable to flooding, there is a potentially far more significant flooding threat should either Falcon Dam or Amistad Dam fail. In April, 2007, a team of safety inspectors classified Falcon Dam as “priority: conditionally unsafe,” or as third highest in a five-tier priority classification system for U.S. dams. In the same month, Amistad Dam was classified as “urgent: potentially unsafe,” or in the second highest priority category. The top priority classification is “urgent and compelling: unsafe.”
The inspectors ordered extensive testing to determine the effects of sink holes and seepage on the two structures. They recommended the testing be included in the next budget cycle.
Next time I will report on the condition of these dams, levees and the overall safety of the Rio Grande Valley. However, due to the failure of the IBWC to respond to a request for information regarding the safety inspections done in 2007, it may not appear before the hurricane season starts. It is apparent from pictures like one found on www.YouTube.com that the facilities are not in the best of condition.
As hurricane season, which starts June 1, inches closer what can taxpayers do? If you are worried about home flooding, the mess, the mold, the cost and so on, get involved.
Regarding localized flooding, contact your county commissioner and ask what the county is doing to help the cities protect your property from loss. Precinct 3 County Commissioner Joe Flores can be contacted at 585-4509. Regarding your safety and protecting our communities from flooding from the river, contact the IBWC Area Operations Manager Rodolfo Montero in his Mercedes office at 565-3159.blog comments powered by Disqus