Houston Too Flat, Soil Too Impenetrable?

Flood Control Planning Director Claims Natural Flood Management Can’t Be Done Here

Advocates Call BS

So Is Flood Control District Working in Our Best Interests?

Sept. 29, 2021

The virtual workshop was all about nature-based flood management (trees, vegetation, greenspace, prairies, wetlands, native gardens), about the value of protecting and restoring floodplains and natural areas, why this green approach costs less, is more effective, resilient and flexible, reduces the long-term risk of catastrophic failure, and adds economic value to communities, not to mention health and environmental benefits.

There were related topics: stopping stormwater where it falls, buying out properties in floodplains, not building in floodways, elevating homes, and how protecting floodplains and green areas reduces the cost of flood insurance, among other things.

But then came the long-time planning director of Harris County Flood Control who all but laughed at the idea of nature-based flood management. Harris County is covered in “impermeable clay soils,” he said.

It’s a common refrain from naysayers, including the leaders of Flood Control, who claim prairies, rain gardens and green infrastructure can’t work here because the land is basically as flat and impenetrable as concrete. Local landscape architects, hydrologists, environmentalists, and others have encountered this obstinacy for years. “Nonsense” and “bs” are typical off-the-record responses.

The obvious conclusion, if you follow the logic of Flood Control: we have to keep doing costly engineering projects, hand out more lucrative contracts, bulldoze and dredge and deepen and widen our streams. And then hand out more contracts to do it all over again. Because that’s what Flood Control does: projects and contracts.

Never mind how bulldozing, dredging, etc. compacts the soil and makes it less absorbent, killing all the healthy, useful organisms in the banks and bed, and increases flooding and erosion. (See also here.) It’s more lucrative (for somebody) to keep tearing down and developing the forests and prairies, though ultimately it costs the taxpayers more. Fill our flowing streams as fast as possible, flood our neighborhoods upstream and downstream – because, according to Flood Control, the natural landscape is no different from concrete and rooftops anyway.

But It’s Not True

But is it true? No.

In fact, most of the soil in Harris County is moderately highly absorbent to very highly absorbent. Furthermore, plant roots help facilitate the infiltration of rain where the soil is less absorbent, especially if we let the grass grow higher and plant native plants.

At a recent education program for local officials sponsored by Texas A&M, Ataul Hannan, director of planning for Flood Control, showed a photo of downtown Houston during the infamous 1935 flood. He said that the Katy Prairie, which once extended from the edge of the Spring Creek forest northwest of the city south to beyond forested Clear Creek in the southeast, was undeveloped at the time. (Apparently meaning that it wasn’t covered in houses, shopping centers, and roads because the prairie then was already ranch and farmland.)

Said Hannan: If the prairie was all that great at slowing or storing stormwater back in 1935, why did downtown Houston flood?

And the correct answer, as determined by the Texas State legislature in 1937, is that a narrow, badly designed bridge blocked the flow of stormwater from Buffalo and White Oak bayous and caused it to back up and flood downtown Houston in 1935. (See our report here.)

Downtown Houston during the 1935 flood. Photo from the former Houston Press.

Nevertheless, the state legislature in 1937 authorized the establishment of the Harris County Flood Control District to aid the US Army Corps of Engineers in stripping the forests, straightening the meanders, and covering our once-beautiful major streams in concrete. (Never mind that the enabling legislation also charged Flood Control with the “conservation of forests.”)

It was a disastrous policy that has only increased flooding, damaged our water quality, destroyed our natural environment, and created the need for costly, continuing maintenance. (See Brays Bayou, a joint channelization project which began in the mid-1950’s and now, after more than seventy years of increasing flooding and hundreds of millions of public dollars, they are almost done.)

Read the rest of this report.

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Let’s Return Native Plants to Houston!

Podcast Interview with Katy Emde, Local Native Plant Expert

Sept. 28, 2021

In this episode Niven Saleh of Houston and Nature looks at Houston through the lens of a native plant enthusiast. Katy Emde is an expert member of the Native Plant Society of Texas and an advisory board member of Save Buffalo Bayou. She explains in the podcast why native plants are great but sometimes hard to find, what she does to source the best seeds and why you should be inspired to give native plants a try.

In the 53-minute episode, Saleh and Emde provide numerous resources including guides and gardens, and places to buy native plants. They discuss plants that work best in Houston, the difference between native and non-native plants, places and apps, books and websites for learning about and identifying plants.

Saleh provides a transcript of the interview here. The website page also includes a list of resources and plants discussed during the interview.