Flood Control’s Destructive Bayou Maintenance Will Lead to More Erosion, More Maintenance
Practices Fall Behind Standards Elsewhere
June 3, 2018
For months we have been receiving complaints about the damage the Harris County Flood Control District is doing to Buffalo Bayou.
Citizens have been sending us video and photographs of contract workers dredging, banging, mucking, bulldozing, slamming and damming the channel and banks; dragging, cutting, and removing large trees, live trees, trees fallen against the banks, trees fallen in the woods.
And now we have reports that they’ve done the same to Cypress Creek in northern Harris County.
The “maintenance” they have done – virtually clearing out the channel and banks — will lead to greater erosion and instability, more sediment and more flooding. And more costly maintenance.
Harvey and the flooding that followed left a huge amount of woody and other sorts of debris in our bayous, our natural drainage system. Buffalo Bayou, our main river, flows from its source in the Katy Prairie for some 75 miles east through the center of Houston, becoming the Houston Ship Channel and emptying into Galveston Bay. For much of that route, the 18,000-year-old bayou remains one of the few relatively natural streams in the city. It accumulated a lot of debris, logjams and snags during Harvey, as did Cypress Creek.
The Importance of Fallen Trees
There are trees along Buffalo Bayou, great tall trees in places, and they sometimes fall into it. Trees have been doing this on rivers for over a hundred million years. Trees, before and after they fall, are a crucial part of the river’s natural system. Overhanging trees shade the water, regulating the temperature. Their extensive roots, together with the roots of riparian plants, anchor the bank, protecting the bank from washing out. When trees fall into the channel, they continue to provide stability to the stream and its banks, trapping sediment, fortifying against and deflecting heavy flows, helping the channel to maintain a healthy width and depth and to form riffles and pools, helping the stream to restore itself more quickly after a flood, and providing food and habitat for the diversity of creatures large and small that sustain the bayou’s ecosystem.
Flooding in SE Texas: The Science Behind the Floods
Hear What Scientists Have to Say About Flooding in the Region
The Houston Geological Society, in cooperation with local universities and agencies, has organized a two-day educational conference bringing together stakeholders, including business, scientists, engineers, citizens coalitions, and government agencies to exchange current knowledge and ideas for the future.
Speakers include representatives from Rice University, University of Houston, the US Army Corps of Engineers, Harris County Flood Control District, the City of Houston, and others. The list is here.
The conference takes place next week, Wednesday and Thursday, June 6 and 7, from 7:30 a.m. to 5 p.m. at the University of Houston, Student Center, 4455 University Drive, Houston 77204. Cost is $200.
Save Buffalo Bayou is a sponsor of this event.
Flood Control Releases List of Projects for August Bond Election
Series of Community Meetings Planned
May 31, 2018
Updated June 4, 2018
The Harris County Flood Control District on Wednesday, May 30, posted on its website an interactive map of projects proposed to be funded with the proceeds of a $2.5 billion bond election scheduled for vote on Aug. 25.
You can see the map of the bond program here.
The schedule of community meetings to discuss these projects is not yet complete but you can find the list here.
And here is where you can make a comment to the flood control district about projects in the Buffalo Bayou watershed.
We’ll have more on this soon.
Tell Flood Control: No! Stop Destroying Forest on Buffalo Bayou
Stop Stormwater BEFORE It Floods the Bayou
May 30, 2018
Harris County Flood Control plans to destroy forest on the south bank of Terry Hershey Park in west Houston in order to create 100-acre feet of stormwater detention siphoned off of Buffalo Bayou. This minor amount of detention is to compensate for INCREASED stormwater that the City of Houston plans to drain into the bayou from surrounding neighborhoods. We need to stop stormwater BEFORE it enters our streams. Tell Flood Control you are OPPOSED to the project by taking their survey on this page. Do it now! They’re starting soon. The survey doesn’t really let you say no to the project. But you can express your opposition and displeasure in the comment box at the end.
Power and Will: Eminent Domain for Preserving Land and Surviving Floods
The Moral Hazard in a Golf Course
May 18, 2018
Mention “eminent domain” and ugly associations come to mind. The brutal power of the state. Taking homes and beloved ranch and farm land for development of oil pipelines, highways, powerlines, private for-profit rail lines. Destroying neighborhoods in the name of “urban renewal.” Condemnation.
But what if the government instead used its power of eminent domain to preserve undeveloped land urgently needed for stormwater detention and green space? It can do that. Other cities have done that. Why, the government can even use this power to preserve much needed affordable housing, say for people displaced by flooding. Local governments elsewhere are doing that. (See New York City and Richmond, California.)
Recently there has been controversy over the City of Houston’s role in allowing residential development on more than 100 acres of an unused golf course on Gessner Road in west Houston just east of Addicks Reservoir. Discussion has focused on the folly (and taxpayer burden) of constructing (federally-insured) homes in a floodplain.
But the more critical issue is that local golf courses, including this particular golf course, have been identified as one of the few remaining sources of undeveloped land vitally needed for detaining stormwater and reducing flooding in our highly developed city.
The golf course in question, Pine Crest, drains into Brickhouse Gully, which in turn drains into White Oak Bayou. Both streams are among the top ten fastest rising streams by flow in the state of Texas, according to a recent study by hydrologist Matthew Berg. Also in the top ten is Cole Creek, which flows into the same spot, pointed out Berg in a recent interview.
The decision to allow development of this open space, instead of using it for stormwater detention, is a prime example of creating a moral hazard: placing people in harm’s way knowing that others will pick up the tab for the damages.
No Dispute: This Green Space Is Urgently Needed to Hold Rain Runoff
Neighborhoods along all of these streams have experienced repeated flooding, reported the Houston Flood Mitigation Consortium, a group of local scientific experts organized after Harvey. The consortium recommended creating detention, among other remedies, along these streams in its recently released report. (p. 44).
Springtime on Buffalo Bayou
Through the Woods on a Brilliant Sunday Morning
April 19, 2018
At last spring had sprung. The trees were bursting with joyous green, celebrating by tossing enormous amounts of pollen into the air. Time for our seasonal photograph of that Bend in the River. Our dedicated photographer Jim Olive was preoccupied with saguaro cacti in California, so it was up to a couple of lesser talents to document Spring 2018 on Buffalo Bayou.
We set off from the small parking lot on the South Picnic Loop in Memorial Park and headed down the path into the woods. The sunlight sparkled through the trees, though some of our old friends had fallen, lying now against the slumped bank. The bayou, now visible through those that remained, was closer. Flow was about 650 cubic feet per second after a brief thunderstorm the day before. The dirt path was soft. We were delighted to see that the high bank in the park that had been damaged and defaced by the unauthorized installation of a rogue mountain bike jump has healed. The wooden jump that had been pounded into the very edge of the bank has been removed, and only a few holes remained.
The last time we had walked in these woods the rolling landscape, carved by ravines, was brown, muddy, monotone, and empty. The trees were skeletal. Winter can be frightening that way, especially in a city so badly hurt by an unprecedented flood. Would life return?
But now the banks that had slumped during the high waters from Harvey appeared to be healing. There was still little ground cover on the slopes of the small tributary that drains the center of the park, and the winding path of the tributary was much changed. One could now see from the shallow creek over the diminished bank of the bayou towards the distant golf course on the south bank far downstream, stripped of trees and vegetation years ago and now covered in plastic sheeting by the River Oaks Country Club.
Elsewhere the bayou was renewing itself, adjusting to our changing climate. Here is the Bend in the River that we have been documenting through the seasons for the last four years. You can see the entire series here.
And here is a photo looking upstream from the same high bank in Memorial Park.
Why “Improving Conveyance” Doesn’t Work
It Causes More Flooding
Taming the Mighty Mississippi May Have Caused Bigger Floods
Human meddling with the river is blamed for most of the rise in flood levels, but the role of climate remains unclear
Now a new study raises the possibility much of the effort humans have put into trying to control the mighty river has paradoxically made its large floods more destructive. The magnitude of so-called 100-year floods—massive inundations defined as having a 1 percent chance of occurring in any given year—has increased 20 percent in the past five centuries on the lower Mississippi, researchers reported this month in Nature. The bulk of the increase has been in the last 150 years, when human engineering of the river has been most intense. “We’ve channelized the river, we’ve straightened it,” says Samuel Muñoz, lead author of the new study and an assistant professor of marine and environmental sciences at Northeastern University. “We’ve made the gradient steeper, and we’ve encased the river in concrete mats and lined it with levees.”
The resulting physics is straightforward, Muñoz explains. With little leeway to meander and limited floodplain to spread over, the waters of the Mississippi in places are corralled into a relatively narrow chute, making peak flows higher than they would be otherwise. Muñoz and his colleagues estimate about 75 percent of the increase in 100-year-flood magnitude is due to river engineering, with the rest attributable to natural climate cycles. The study was not able to factor in the influence of anthropogenic climate change effects, though, leaving open the question of how much rising flood levels are driven by engineering and how much by a warming climate.
Read the rest of this article in Scientific American.
Lessons From Hurricane Harvey
Academic Experts Speak on What Can and Should Be Done About Flooding In Houston
March 30, 2018
Daniel Grossman reports for Re.Think on the annual American Geophysical Union meeting in New Orleans in December 2017. He also visits Houston and gathers opinions from local academics. Buyouts, making room for the river, stopping storm runoff before it floods our streams are some of the necessary strategies recommended here and elsewhere by those who study these things.
Heavier, More Frequent Rains
At the New Orleans conference, Emanuel laid out findings he’d published a few weeks earlier in the scientific journal Proceedings of the National Academy of Sciences. Simulating mayhem in a computer program, he’d released thousands of virtual past and future “seed” storms into the Atlantic Ocean and computed their tracks. The likelihood of a storm about as rainy as Harvey has increased by a factor of six in the last 40 years, he’d found. By 2100 the chance of such a deluge will increase another threefold. Then, a Hurricane Harvey will strike Texas once every 5 years.
Buyouts and Room for the River on Buffalo and Other Bayous
Yoonjeong Lee, a researcher at the Center for Texas Beaches and Shores at Texas A&M University at Galveston, says Houston should build Dutch-style flood protection, and she knows where. “Buffalo Bayou would be a perfect place to build a ‘Room for the River’ program.” She says the city could buy up a relatively small number of plots near its banks and – after demolishing any structures on them – construct a riverfront park. The land would be engineered to capture water when the bayou rose, safeguarding remaining districts. Houston has previously installed patches of parkland along its bayous before, but she says the city has to think bigger.
Timon McPhearson, a professor in Urban Ecology at the New School in New York City, says that another way Houston should become more resilient to wetter storms is by controlling how much water rushes into bayous in the first place. He says too much of the rain that lands on the city drains quickly into waterways. “Houston is an extremely paved city,” he says. Replacing street and driveway surfaces with permeable materials will lower peak floods. He also suggests green roofs, covered with vegetation that could provide important ecosystem services that retain – and stall – some of the rainwater.
Albert Pope, an architect at Rice University, doubts that adaptation through infrastructure fixes are sufficient to keep Houston safe from serious flood damage. He says that there’s too little undeveloped land left to accommodate new reservoirs of sufficient capacity, and that further straightening, widening, and bank-hardening can’t force bayous to carry more water. “We’re at the limits to what we can do, engineering-wise,” he says. His solution is more disruptive of the status quo, and Houston’s fix-it-with-concrete ethos. He insists that Houston should do something more transformative and remove all the buildings in its flood plains – 150,000 structures, including those on three-quarters of the acreage in Meyerland – and turn the acquired land into parks.
Read the article, “Lessons From Hurricane Harvey,” published by Re.Think on March 15, 2018.
High Flows in Harris County Streams Increasing Most in Texas
Study Questions Use of Dams and Urges Focus on Causes, Not Symptoms, of Flooding
County Commissioners to Discuss Flood Strategy, Funding, Tuesday, March 27, 10 a.m.
March 26, 2018
An “incredible” 70 percent of stream gauges in Harris County show significant increases in peak flow – as much as 6,400 percent in one case — since the beginning of record keeping by the US Geological Survey.
More streams in Harris County are increasingly flowing higher than in any other part of the state, according to a study recently published in the March 2018 issue of the Texas Water Journal, a publication of the Texas Water Resources Institute.
Three stream gauges on Buffalo Bayou have shown the greatest increase in peak flows since the federal dams were built in the 1940s to reduce flooding on the bayou, according to the report.
Significantly, two major streams, Langham and Bear creeks, feeding into one of these dams — the overburdened Addicks Reservoir — showed some of the largest upward trends in peak flow. The record amount of runoff flowing into Addicks during Hurricane Harvey was a major factor in the unprecedented decision to open the floodgates on both dams during the storm in order to prevent the dams from overtopping. Thousands of homes both below and behind the dams were flooded, and three people died.
The area in western Harris County above and behind Addicks Reservoir is experiencing some of the greatest development pressure in the region, particularly since the construction of the Grand Parkway (Highway 99). Buildings, paved surface, and other hard structures, including pipes, associated with development cause more and faster and more polluted rain runoff into streams, leading to flooding.
“An Overreliance on Flood Storage Reservoirs”
The report noted “the difficulty of maintaining lower peak flows below a reservoir when the inflows to the reservoir exhibit extraordinary increases year over year.”
“It is much easier for impoundments to store flood flows when these flows are not rapidly increasing on an annual basis. Thus, relying on large impoundment projects alone likely will not achieve success and again points back to our central emphasis of identifying causes, not just symptoms [of flooding].”
The study, titled “Peak Flow Trends Highlight Emerging Urban Flooding Hotspots in Texas,” was authored by Matthew D. Berg, CEO and Principal Scientist, Simfero Consultants, in Houston.
The USGS gauge on Greens Bayou at Cutten Road in northwest Harris County experienced the greatest increase in peak flow – 6,400 percent over a period of several decades.
Other rapidly increasing stream flows are occurring in Keegans Bayou at Roark Road in southwest Houston (nearly 5,000 percent), Greens Bayou near Highway 45 in north Houston (1,200 percent), Langham Creek near Addicks Reservoir in west Houston (750 percent), and White Oak Bayou near Heights Boulevard (600 percent).
Harris County Commissioners Court will meet Tuesday, March 27, to discuss flood management strategies and a possible bond referendum to pay for them. Also on the agenda is a proposal to study the feasibility of digging massive tunnels to drain stormwater from western Harris County into Galveston Bay. The contract to be negotiated is with Fugro USA Land, Inc.
The commissioners’ meeting begins at 10 a.m. on the ninth floor of 1001 Preston in downtown Houston. Those who wish to speak can sign up before the meeting here.
Rain Watchers Needed
Be A Backyard Rain Counter. Help Science
March 19, 2018
Message from the Community Collaborative Rain, Hail, and Snow Network:
The Community Collaborative Rain, Hail & Snow Network (CoCoRaHS) is a grassroots, non-profit, community-based, high-density precipitation database network made up of volunteers who take measurements of precipitation right in their own backyards. CoCoRaHS has observers in all 50 states nationwide, the Commonwealth of Puerto Rico, the U. S. Virgin Islands, the family islands of the Bahamas, and in Canada.
Texas CoCoRaHS needs volunteers who have an interest in weather observing and who would enjoy observing and reporting daily precipitation amounts on our website. Volunteers are asked to obtain an official CoCoRaHS scientific rain gauge and place it in a strategic location. They take daily precipitation measurements at approximately the same time – usually 7 a.m. – and record those measurements. Daily reporting of data is preferred, as days without precipitation are just as important to know as days with rainfall.
Many agencies rely on precipitation data collected by CoCoRaHS during and after rainfall and flood events to determine where the most rain has fallen and where the potential for flooding is greatest. CoCoRaHS’s volunteer precipitation reports help to fill in the gaps between official rainfall data collection sites in our region, such as the Harris County Flood Control District’s Flood Warning System, the National Weather Service’s climate sites, and the Lower Colorado River Authority’s Hydromet system.
The data reported by volunteers is organized and displayed on the CoCoRaHS website for use by scientists, researchers, and emergency managers – as well as the general public. The Harris County Flood Control District, National Weather Service, U.S. Department of Agriculture, and West Gulf River Forecast Center utilize CoCoRaHS data in their work, along with engineers, meteorologists, hydrologists, climatologists, insurance adjusters, ranchers and farmers, and many more.
The Houston/Galveston region of the CoCoRaHS Network consists of volunteers in 15 counties: Austin, Brazoria, Chambers, Colorado, Fort Bend, Galveston, Harris, Jackson, Liberty, Matagorda, Montgomery, Polk, San Jacinto, Waller, and Wharton counties. The network needs many more volunteers to better measure precipitation across the region. Weather hobbyists and those citizens who measure daily rainfall totals such as Master Gardeners and Master Naturalists are strongly encouraged to join CoCoRaHS.
To join, go to the CoCoRaHS website and click on the “Join CoCoRaHS” emblem in the upper right corner of the homepage. The website also has information on the organization’s background, observer training and educational tools, where to purchase the required CoCoRaHS rain gauge, how and where to set up the gauge on your property, and much more.
Please take a moment to tell a friend or neighbor about this exciting grassroots effort of citizens measuring precipitation right in their own backyards. It’s easy to join, takes only five minutes a day, and is a fun way to learn about this wonderful natural resource that falls from the sky. Your observations continue to give scientists an ever clearer picture of where and how much precipitation falls throughout our communities.
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