Removing Trees on Buffalo Bayou Because It’s Cheap and Easy

A Stormwater Project with Little Benefit and A Lot of Uncounted Cost

 

February 26, 2019

A large number of trees will be cleared in one of the city’s last remaining public forests on Buffalo Bayou because it’s the “easiest and cheapest” stormwater project to do, city and county flood control officials explain.

The trees are being removed to dig out shallow basins on the bank of upper Buffalo Bayou in Terry Hershey Park in west Houston, a rolling wooded area with paths used by hikers and bikers and wildlife. When the bayou overflows, the basins are meant to hold briefly a modest amount of water which then continues flowing downstream.

But the calculation of “cheapest and easiest” does not include future repair and maintenance costs where now there are none. A similar project on the once-forested opposite bank has required many millions of dollars in taxpayer funds for maintenance and repeat repairs to the bank in the decades since trees were cut.

Nor does this calculation include the additional flow into the bayou from the loss of trees and vegetation, which significantly slow and absorb rainfall and runoff. A study by the University of Arkansas reports that removing forest can increase runoff into streams by as much as four or five times. (p. 3)

It does not consider the financial value that the forest provides by cleansing the water and the air for free. Studies have shown that riparian vegetation is cheaper and more effective at cleansing our polluted water than even sewage treatment plants. A study of Houston’s urban forest by the US Department of Agriculture found that even including invasive trees, our modest tree cover captures carbon and other pollutants from the air worth hundreds of millions of dollars.

Also not included: the value of the mental and physical health benefit that trees provide to Houstonians, who suffer from a deficit of nature, many of whom were traumatized by the flooding from Harvey. Since ancient times wise people have known that the experience of even a small piece of nature has health benefits. (See also here.)

Looking downstream on the straightened channel of Buffalo Bayou in the area where trees are to be removed and basins excavated in Terry Hershey Park in west Houston. Photo June 2018.

 

Nature is the Best Engineer

Making room for the bayou to overflow is a good thing, as is a focus on detention or “slowing the flow.” Cutting down trees and removing vegetation next to the bayou is not.

“Engineers have a hard time understanding,” says Bob Freitag, director of the Institute for Hazards Mitigation Planning and Research at the University of Washington and co-author of Floodplain Management, A New Approach for a New Era. “Trees aren’t in their model.

“We want trees,” says Freitag. “Trees do a lot of good things.”

There is a new field of engineering that understands and imitates the process of nature, melding engineering and biology and valuing ecosystem services, points out Freitag. “But those who do it are few and far between. It’s a pretty new field.”

No Reduction in Flooding

The planned detention basins next to the bayou channel do not even reduce flooding, despite a popular belief that they will. Officials confirm that the small basins will do nothing to reduce flooding downstream. “No, they’re not going to save people from flooding downstream,” said Matt Lopez, the Harris County Flood Control District’s Precinct 3 coordinator. “They’re not going to save folks from Harvey or any other storm.”

Read the rest of this post.

11 thoughts on “Removing Trees on Buffalo Bayou Because It’s Cheap and Easy”

  1. Sharon N. says:

    Let’s put in big 30 x30 inch rocks to decrease erosion and plant trees, and first put down clay soil and deep rooted plants and put the big rocks at strategic areas with other big rocks to keep our nature lovely for man and animals…a healthy environment. I am so glad you care. I have lived here and was born here! Yes, keep Houston beautiful with healthy nature!

    1. Thanks for caring, Sharon. Yes, we all need healthy nature in Houston. At the moment there are plenty of trees on the south bank of upper Buffalo Bayou in Terry Hershey Park.

      However, “big rocks” are not natural to our bayous, though we do have layers of various types of sandstone in the channel and banks, which is one reason why the bayou in places is fairly resistant to erosion. But in Buffalo Bayou our primary type of bank collapse is slumping or sloughing. The best protection against that is leave trees, including fallen trees, and vegetation in place, don’t landscape or irrigate or mow, don’t build sidewalks or houses or golf courses on the bank, and stay back. With fallen trees and vegetation in place, a slumped bank will naturally rebuild and replant itself.

  2. Harriet Festing says:

    This is so terribly sad, and the same thing is happening across the country.

    H

  3. Jim Langley says:

    A year ago I spoke with everyone who would listen, and wrote letters to those who wouldn’t, to plant an idea for flood water management. To date, I have heard nothing at all. No feedback, no suggestion in news articles that my idea was considered, even if rejected.

    The idea is to dig a Big Ditch from the headwaters of the Barker/Addicks reservoirs, straight south to the Gulf. This relief system would allow heavy rainfall on the west side of Houston to reach the Gulf without going down the serpentine Buffalo Bayou and through the city of Houston.

    This Big Ditch would be straight and true, designed to carry the most water, quickly away from the rainfall areas. Built through what is currently farm land, it would be the lowest cost solution, even when installing cattle bridges to allow continued ranching along the way.

    It would also cross the Brazos and Colorado rivers, which often flood when rains fall to the north. The Big Ditch would then allow secondary pathways for drainage, possibly eliminating future flooding in Fort Bend and Brazoria counties. The western suburbs of Houston would then be more attractive for residential and commercial development, with commensurately higher tax bases.

    In discussions with my civil engineering friends, the figure $10-15 billion becomes the consensus for cost. A lot of money, but less than expansion of Buffalo Bayou or deep tunnels, and higher property values along the way.

    Is anyone listening?

    1. Dear Jim Langley,

      Thank you for your comment. Perhaps the reason you are getting no response for your idea of a big, straight drainage ditch running from the federal flood control dams in west Houston directly to the Gulf is that it is an outdated, costly idea that doesn’t work. If you read the article, you will find a reference to the fact that federal government as well as other flood management agencies long ago abandoned straight channels for removing storm waters because they increase flooding.

      From the article: “The federal government had stripped, straightened, and shortened the bayou there below the two federal flood control dams, Addicks and Barker, during the late Forties. Straightening—channelizing—the bayou essentially reduced its capacity, rendering future residents more vulnerable to flooding, besides damaging its essential functions. Channelizing streams for reducing flood risk has been largely abandoned by the federal government and agencies elsewhere because it actually increases flooding, among other problems.

      “Modern stormwater management emphasizes stopping, slowing, and absorbing stormwater before it floods a stream, not after. (See Freitag, et al.)

      You might be interested in the opinion of the American Society of Civil Engineers contained in a 2014 report criticizing the “tendency, for both historical and psychological reasons, to place greater reliance on traditional structural measures [dams and reservoirs, digging up bayous and ditches, for example] even though in the long run nonstructural and nature-based measures tend to be more efficient and sustainable solutions.” The report called for a national flood risk management strategy. (See page 27.)

  4. Jim Langley says:

    Thank you. Finally a response. While I appreciate and understand the retention argument – I also have a degree which includes hydraulics – that approach only makes sense when dealing with existing meandering waterways. The Big Ditch is best thought of as a drainage pipe. It is there only to drain a specific area very quickly into a large reservoir. Addicks/Barker into the Gulf of Mexico. No stops along the way. That is why sewer pipe drain from the house straight to the mainlines. We don’t want to retain it along the way.
    In all fairness I did originally receive a response from the flood control agency. They said any plans considered could not cross watershed lines. It made me wonder how lock and dam systems ever got built.

    1. Thanks again, Jim.

      But actually we do want to hold back the rainwater that drains from our house to stormwater lines. That’s why other cities around the country have programs for people to detach the downspout from the sewer line.

      See this about that from the Environmental Protection Agency: Soak Up the Rain: Disconnect / Redirect Downspouts.

      It’s not clear whether your idea is for a big open ditch or for an enclosed pipe. A big straight open ditch, of course, would likely overflow and unless it’s lined with concrete, would require constant dredging, maintenance and repair. Well, even if it were lined with concrete. A closed pipe would send horribly polluted urban runoff directly in the Gulf, as would a concrete ditch, among other problems.

      Collecting more and more runoff faster and faster is exactly the opposite of the way we should be thinking of these problems.

      See the book referenced in the article, Floodplain Management, A New Approach for a New Era.

  5. Kay Haslam says:

    This is the HCFCD “In Line Detention” Project that proponents claim will enable TxDOT /TIRZ 17 /COH to do the Memorial Drive Drainage and Mobility Improvements Project. Their position is that cutting down the trees and digging up three shallow overflow basins on the bank of Buffalo Bayou will allow TxDOT to dump stormwater from the Sam Houston Tollway Frontage Road trunkline that drains the Beltway 8 system into ditch W153, a tributary to Buffalo Bayou. They also argue that the basins will allow the dumping of runoff from West Bough, which drains CityCentre and T & C Village, into Tributary W153. Stormwater runoff from Memorial Drive, Tallowood, Attingham, Benignus, and Frostwood will be dumped into W153 also. W153 already takes runoff from Fonn Villas and Memorial Green.

    So in their view cutting down all the trees and digging three shallow depressions will provide detention that will offset all the additional sources of storm water that TxDOT will be adding to the bayou. Of course not, but these people do not care.

    1. Thanks, Kay. Note that Ditch W153 was formerly a winding creek that flowed through the woods near what is now Hollow Drive, under what are now Somerset Place and Legend Lane, and emptied into Buffalo Bayou. It was channelized and rerouted, and houses built on top of its natural path when Memorial Drive was extended and subdivisions developed in the Seventies. Streams have a memory and will seek out their natural channel.

  6. Kay Haslam says:

    Tributary W153 is fed by a natural stream that arises northeast of the Tallowood bridge. The stream is crystal clear and flows year round. The stream shelters a variety of wildlife and migrating birds and butterflies. It is a lovely secluded site with rolling terrain and tall trees.

    Incredible that TxDOT/ TIRZ 17/COH have chosen this Tributary to dump the storm water run off from that concrete jungle on the Southeast quadrant formed by the intersection of Beltway 8 and IH-10. Toxic, oily water with pesticides and antifreeze is coming to W153, unfiltered and untreated. What about the turtles and the beaver and the owls and the hummingbirds?

    1. Maybe the Texas Commission on Environmental Quality and Corps of Engineers need to be reminded about the potential impact of the polluted drainage into this Buffalo Bayou tributary, which is under federal protection through the Clean Water Act.

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