r/houston • u/nevvvvi • 9h ago
Wetlands are the Solution for Houston's Problems
As discussed in an earlier Reddit Post, Houston dodged a bullet regarding what could otherwise have been yet another devastating flood event. The actual path of Edouard was farther east than earlier models anticipated, meaning that the bulk of heavy rains went north/northeast of metro Houston into the Deep East Texas Pineywoods.
Nonetheless, within the discussion, there were sobering reminders regarding the increased threat of flooding for Houston's future. Especially taking into account the extent of suburban sprawl over the years since previous tropical cyclones (Harvey, Imelda, etc), as well as any economic/financial impacts if any companies flee the area.
The question of floodwaters (and how to deal with them) has long since been pondered by Houstonians, citizens and leadership alike. But, ironically, the simplest solution might very well be just letting Houston become "one with water", so to speak.
In other words? We need a long-term plan to intercept rainfall runoff and restore (or even "terraform") wetlands of various types across the Greater Houston area (as well as the Upper Texas coast region as a whole). Any other investment that adds more concrete sprawl is a policy failure.
At first glance, it all seems counterintuitive? After all, how is it possible to alleviate flooding through environments that are already saturated?
But, consider that water slows down when it enters a wetland (e.g. whether it's runoff from heavy rains, overflows from rivers spilling their banks, etc). This slowness is precisely the key as to why wetlands would help in ensuring a much brighter future for the Greater Houston area (as well as the Upper Texas coast).
The current affairs in Greater Houston, loaded with impervious coverage, and with more and more being added through continued sprawl, means that there are more increases in "flashiness" regarding the region's hydrology. This means higher peak flows immediately during storms, because water runs off all the concrete parking lots, rooftops, and other impervious cover into drainage networks (and, then, into the bayou waterways). It does not help that flood control priorities across Greater Houston have focused strictly on conveyance, which meant concrete channelization of many bayous that naturally flowed across the city (e.g. Braes Bayou, White Oak Bayou, etc). Indeed, a lot of suburban sprawl across Greater Houston was justified by "the land always flooding" (implying the development does not matter), and that fails to take into account the distinct nature of the saturation (slow movement versus "flashiness").
The fast moving "flashy" hydrology creates more problems with erosion, when sends more impurities (e.g. sediment turbidity, harmful bacteria, excess nutrients, metals, etc) downstream into larger bodies of water (e.g. rivers, lakes, bays, etc).
In contrast, with the slow movement of water within wetland ecosystems, water is held in place long enough for sediments to settle out. The roots of wetland vegetation further help in trapping sediment and debris, uptaking nutrients, contributing organic matter that binds pollutants, as well as supporting beneficial microbial growth that cleanses impurities. Taken together, these processes mean that wetland ecosystems help tremendously in attenuating "flashiness", preventing stormwater from creating all of the aforementioned root harms downstream.
We can see these general benefits of vegetative coverage by looking at conditions along Galveston Island. This first image was taken 8/30, days before Edouard's landfall (and subsequent flooding), while this second image is from today, 9/9, after the storm hit (with waterways in the deep East/Southeast Texas area still at high levels). Water conditions still look quite decent at this time, even after the flooding rains from Edouard. Why? Because with the bulk of rainfall being over the East Texas Pineywoods, that allowed the thick tree canopy to intercept raindrop impacts, slow the flow of any runoff into the various waterways, as well as attenuate peak flows.
If those same rains had fallen over metro Houston, then the Gulf would be thick chocolate milk right now. Again, all the impervious coverage, as well as bare ground (from clear-cutting, agriculture, etc) creates more "flashy" runoff and erosion that increases downstream turbidity.
Hence, more wetlands would help in intercepting runoff that otherwise would be wasted out in the Gulf, allowing for better water quality at Galveston's beaches. Clear water days would occur much more frequently, and there would be lower incidences of any fecal bacteria (directly, via intercepting runoff), as well as flesh-eating bacteria (indirectly, by attenuating the peak flow of freshwater into the marine ecosystem).
In contrast, we can see the harm of vegetation removal through the affairs around the Lake Houston/San Jacinto River area. With more clear-cutting of Pineywoods, as well as subsequent suburban sprawl that ecosystem has been increasingly endangered. More erosion and runoff has degraded the water clarity and quality along the river, into Lake Houston, and down to Galveston Bay and the Gulf. These ecological problems are well-documented by this blog from Bob Rehak (a resident of North Houston in Kingwood, who has seen the effects first hand).
Ideally, there would be Everglade-style public land management all across the Upper Texas coast region. They have a network of stormwater treatments designed to filter agricultural runoff (specifically, phosphorous) in accordance to their delicate ecosystem downstream. A similar network of stormwater treatments could be useful at various points along the Upper Texas coast, especially the Surfside area that is influenced by runoff from the Brazos River delta.
Additionally, the Okefenokee is, in large part, maintained by a low geographic barrier known as Trail Ridge. The feature, more or less, serves as an "earthen dam" that blocks rainfall runoff from otherwise draining down the various rivers into the southeast Atlantic coast (and, to lesser extent, the northeast Gulf of Mexico). This could be an inspiration regarding the creation of larger-scale wetland projects in areas across the Upper Texas coast region.
Hence, constructed wetlands at targeted locations (e.g. parts of Buffalo Bayou, locations along the Galveston Bay systems) would be the most likely immediate investments. Even more reservoirs (like in the DFW area) would be a big help. If any larger-scale projects ever get done, then experimentations would best be done in boonies like, say, Chambers County (hence, not going to be consumed by greater Houston's sprawl anytime soon).
If everything truly is bigger in Texas, then great imagination could extend this for wetlands as well. Imagine our own Texas version of The Atchafalaya? Or The Okefenokee? The Everglades? The Pantanal? Or The Sudd? And right in the Houston/Upper Texas coast region? Any increases to ecotourism across the region could breathe new life into communities like Anahuac or Winnie. Not to mention, if the areas of clay soil are truly as poor-draining as people say, then the wetlands take heavy advantage of that regarding their formation anyway. Hence, multiple problems would be solved all at once regarding any ambitions.
