This is in response to M. Dailey’s mistake-filled letter in the April 3, 2018 edition of the Valley Morning Star.
Hurricane Beulah occurred in September of 1967, not October. The flood did not destroy the high expressway bridge from F Street over the Arroyo, but did damage it and a new span was added later.
The large flood after Beulah came from the Rio Grande several days after the storm had passed and the flow in the Arroyo from local rains was mostly gone. The Beulah flood was not caused by local rainfall in Cameron and Hidalgo counties. Only part of the run-off from Hidalgo County goes into the Arroyo. A lot of the rain runoff goes into the North Floodway and the large drain from Edinburg to the Laguna Madre.
The Flood Control project in the Valley is operated and maintained by the International Boundary & water Commission (IBWC). The Rio Grande in the flat Valley areas gets smaller as it goes downstream and historically flooded large parts of the Valley in both the U.S and Mexico before there were any manmade works to control floods.
The Arroyo is part of the Flood Control Project. At the time of the Beulah flood, the U.S. Floodway Project was designed for a flood of 187,000 cubic feet per second at Rio Grande City. The Beulah Flood measured 220,000 cfs and there were no records of a flood this large.
The flood distribution plan calls for 21,000 cfs to go into the Arroyo Colorado Floodway. Because of a structure failure during the Beulah Flood, about 60,000 cfs went into the Arroyo and caused a lot of damage. There have been lots of improvements made to the flood control project since then and I do not think it will happen again.
Preparing for a flood does not seem to be important to you, but it is very important to most people, especially those who suffered major damage in 1967.
The IBWC does not want to, as you say, “scour the banks of the Arroyo.” Thick vegetation on the banks is good revetment and provides a lot of protection. However, tall trees on the banks sometimes cause damage. When the ground around the roots gets saturated with water, the weight and leverage of a tree can sometimes cause it to pull out the roots and fall and pull out some soil.
M. Dailey, you think slowing the velocity of flood water in the Arroyo would be beneficial, you are wrong.
If you flow the floodwater, you will cause the elevation to be higher and thus cause more people to be flooded. None of us wants this.
The IBWC has recently cleared some brush and trees on both sides of the water channel in the Arroyo downstream of Highway 77 to improve the flow. In my opinion, no enough clearing was done. With a design flow of 22,000 cfs, I believe the flood elevation could be considerably higher than design and might cause more damage.
I would be glad to meet with you or any group and explain the Floodway Project and role of the IBWC.
I have a flood distribution plan in mind that could reduce the amount of flood water in the Arroyo and allow trees and brush to grow anywhere. The problem is, it would cost millions of dollars.
If the birding organization, city of Harlingen, the US Fish and Wildlife and Sierra Club all got behind it, they might influence Congress to appropriate money for it.
I believe it is feasible, but first a study would have to be made. This plan would benefit the whole Harlingen area. I agree the Arroyo is a beautiful place and would like to make this happen. But, I put people’s safety and welfare first. I am sending my plan to the Valley Morning Star.
Sincerely, Joseph J. Tucker, P.E. Harlingen
