In October of 1967, Hurricane Beulah deluged the Valley with over 12 inches of rain, and the ensuing overflow of the Arroyo Colorado caused catastrophic flooding in Harlingen.
The flood surge down the Arroyo was so large, that it destroyed the ‘F’ street bridge overpass, and almost put water over the roof of the Valley Morning Star office building.
However, the flooding of Harlingen was not caused by the 12 inches of rain that fell locally, but by the 12 inches that fell in Hidalgo County, which was delivered to Harlingen by the International Water and Boundary Control via the Arroyo in the name of flood control.
Until it was altered by the IWBC the Arroyo was nothing more than an ancient, usually dry, distributary of the Rio Grande that serves mainly as a conduit for street drainage and sewage effluent for cities upstream from Harlingen.
The IWBC’s claim that scouring the Arroyo’s banks of plant life today would prevent another Beulah-scale flood tomorrow by speeding water through the Arroyo is simply unfounded.
During a freakish rainstorm in April of 1991 that dumped 19 inches of rain in Cameron County, Harlingenites who remembered Beulah flocked to the Arroyo to monitor its rise. Despite a much larger rainfall (19 inches vs. Beulah’s 12) they saw that the Arroyo did not come close to overflowing.
If an event as rare as a 19 inch rain does not cause the Arroyo to overflow, one wonders if the IWBC is not overreacting simply because it is afraid of being blamed for another Beulah-type flood?
As to the likelihood of another Beulah flood surge: My first house near the Arroyo was inundated in 1967. But when I bought it in 1977, I knew that another Beulah-now over half a century later was so unlikely that it had no bearing on the purchase whatsoever.
In fact, houses along the Arroyo are prized, not just for their view, but because of the privacy afforded by its steep, wide banks. If the IWBC is right about the danger that flooding of the Arroyo presents to nearby property, wouldn’t those houses be undesirable instead of being sought?
Besides localized flood damage, the surge of water down the Arroyo caused irreversible erosion to property along South Parkwood and Riverside Drive as well as along Little Creek.
Two vacant lots at the confluence of the Little Creek and the Arroyo were completely washed away, other houses lost much, or in some cases, most, of their backyards and some were left uninhabitable for over a year. Aerial photographs of South Parkwood taken before Beulah show how much property was lost in that surge. Is it not clear that slowing a flood surge down the Arroyo might prevent such erosion in the future?
Instead of seeking to rush water out of the most drought-stricken area of Texas, perhaps it would be wiser for the IWBC to allow an occasional
rain to replenish the Arroyo and its surrounding native habitat, turning the Arroyo into an oasis of green in this otherwise parched landscape.
This phenomenon can already be observed when a heavy rain pushes the Arroyo into the lowest lying areas of McKelvey Park, briefly covering its grass with nutrient-rich water. McKelvey Park does not even have sprinklers in its lowest areas because of the water furnished by the Arroyo.
Those pesky native plants and trees that keep insisting on growing within the Arroyo’s banks are the only natural barriers to any flood surge, which incidentally, has occurred exactly once in recorded history. Being natives these plants require no insecticide, pruning, watering or fertilizing beyond what the Arroyo and its effluent freely provides. Some might consider that a win-win situation.
In a town whose greatest tourist draw is an annual bird show, one would think nesting sites for birds and the habit for hunting it provides them-which explains the raptors frequently seen there-might also be of some import to the local economy.
Given the recurring catastrophic flooding of Houston and New Orleans, perhaps it is not reasonable for the IWBC to prepare for a once-in-a-lifetime eventfor which it was at least partially responsible- by demanding that the largest tract of native habitat in the city be removed in the name of flood control?
M. Dailey Harlingen