A Celebration of Concrete
Or How to Create Ill Will
March 3, 2023
For those who don’t get enough experience of concrete in the city of Houston, there is now plenty more concrete for you to enjoy in Memorial Park.
Normally one would go to a park to escape the hardness of the built city. We are fortunate in Houston to have a major urban park, almost 100 years old, dedicated to the experience of nature – a soft path underfoot, tall trees swaying gently in the breeze, a glimpse of a rabbit or raccoon, the call of a hawk, the smell of soil, mushrooms and pine; the rhythm of the bayou flowing past. Conservationists have worked for years to try to keep it natural.
But in recent years the private conservancy running Memorial Park on the banks of Buffalo Bayou has decided to turn our beautiful park into a constructed experience. This is a problem with park conservancies: in order to raise money they have to do projects, and in order to raise more money they have to do more projects. It’s never enough to let nature be.
And apparently they have decided that in order to raise money they have to throw donors names in big letters in front of it all. Most recently, in addition to the massive amount of concrete poured to construct not one but two sets of tunnels over Memorial Drive, the conservancy has erected hulking grey concrete walls on both sides of the tunnels announcing who is responsible: Kinder. It’s the Kinder Land Bridge.
Well, we’re not sure that everyone is going to be thanking the Kinders for this, although they have been very generous (see also here) with their pipeline fortune throughout the city.
One Land Bridge Wasn’t Enough
Land bridges for wildlife over (better under) major highways is a good idea. But the idea that a land bridge over Memorial Drive was for the animals (including humans) has always been a farce, as our founding president Frank Smith has long argued. Wildlife – coyotes, bobcat, possum — have always found safe passage through the large drainage culverts passing under Memorial and Woodway. And as we have previously pointed out, the Conservancy has thoughtfully included a drainage culvert designed for wildlife passage underneath the land bridges, which officially opened Feb. 11. Based on reports from neighborhood residents, more wildlife likely died fleeing destruction of their habitat than before construction of the land bridges and prairie.
In addition, for humans who can’t navigate the crosswalks and stoplights to walk across six-lane Memorial Drive and back, there is a lovely, modest pedestrian bridge, known as the Living Bridge, a remnant of an earlier, more enlightened master plan from 2004 connecting the north and south sides of the park near the Running Center. Not that most people often have reason to do that. Generally you are either jogging or walking the Seymour Lieberman trail around the expanded golf course on the north side or strolling, biking, running (or getting lost) with your family and friends through the lovely bayou woods on the south side. (Yes, the Lieberman trail is much improved by routing it through woods and over streams instead of along Memorial Drive.)
But okay, so they really wanted a bridge over Memorial Drive: a high point over our low, flat prairie (and over the trees) from which Houstonians could view the sunset and sunrise and the surrounding vista. That’s cool. But wouldn’t one bridge, one set of tunnels have been enough? asks the amazing Mr. Smith, who at 101 years is still engaged, still concerned about the park that he promised Ima Hogg he would always protect. Did we really have to spend $70 million to build two massive bridges?
Top left: concrete walls surrounding the Kinder Land bridges. Top right: on top of one of the bridges. Bottom: Side view looking north of one set of tunnels. Photos Feb. 17, 2023
More Parks Needed
Do we not need other parks, many more green spaces? The Conservancy often touts the fact that many people drive a long way for the experience of Memorial Park. But we have long argued that maybe they do that because there are few other opportunities. (They certainly don’t do it to look at concrete walls.) Houston ranks 70th out of the nation’s most populous 100 cities in terms of parkland, investment, and access to parks, according to the 2022 ranking from the Trust for Public Land. Although note once again that this calculation is skewed by the vast acreage of parkland included within Barker and Addicks reservoirs in far west Houston, including Cullen Park, at over 9,000 acres one of the largest parks in the country.
The original 1,503 acres that were sold at cost in 1923 by the Hogg Brothers and partners to the City of Houston were intended as “an ideal wooded park” for “the common good.” Though the park is frequently touted as nearly twice the size of New York City’s Central Park, the comparison skips over the fact that more than 600 acres of Houston’s park is devoted to a (recently expanded) golf course, driving range, and related buildings, for which numerous magnificent pines and oaks were cut down. Not to mention the significant amount of acreage used by maintenance, sheds and green houses, or just simply ignored and abused.
But Wait! There’s A Concrete Prairie Wall Too. And Stairs
But wait! There’s more. Wander on over to the new prairie on the south side of Memorial and you can gaze upon another massive grey concrete wall with the names of more donors inscribed in giant letters. We won’t embarrass these generous people by naming them. It’s not their fault that this ugly wall rudely interrupts your view of the new green prairie and wetlands they helped to fund.
Winter in the Woods
They Will Rise Again
Jan. 26, 2023
Step on and over the massive pile of sawn oak trunks. Step on and over the beaten-down wire fencing. And into the people’s woods on Buffalo Bayou where we’re forbidden to go, though people go anyway.
Wait! What’s this? The woods are see-through, barren, leafless. Everything is monochrome brown. The ground, muddy and slippery, is exposed. The sandy paths etched by rivulets of rain; clumps of dead leaves washed down everywhere. Limbs, branches, and thorny vines ripped and wrenched from the trees and thrown on the ground. Yawning gullies, widened by the rain, have eaten away at the edge of the trail.
Oh, yeah. It’s winter. We had a big freeze. (And before that a long drought.) Everything died. And then came a violent storm. Tornadoes tore apart homes and buildings southeast of the city.
The crows are talking about it. Even the everlasting green leaves of the yaupon and cherry laurel are gone.
We’re here on the south side of Houston’s Memorial Park to take a winter photograph of that bend in the bayou. We’ve been documenting the bend from the same high bank throughout the seasons since 2014.
But we don’t remember it ever looking quite so thin and exposed.
We started a little late and were concerned about the sun being too high, rising in the east above the trees on this clear, cold Thursday morning, glaring at the camera. But when we arrive we realize it doesn’t really matter. The downstream trees that usually filter the sun are bare skeletons in the distance. They wouldn’t have softened the light anyway.
It’s cold but not freezing; cold enough to numb the fingertips. The thick mist rising off the water is smoky, swirling mysteriously. The brown water is high and turbulent, though nowhere near flood stage. At around 1,720 cubic feet per second, the flow is about half its peak on Tuesday morning, Jan. 24, during the storm. The floodgates on the federal dams, Barker and Addicks, far upstream were closed then. Apparently they were re-opened Wednesday mid-morning to release stormwater held back in the normally dry reservoirs.
Concern about the Trees and Vegetation
Back in the office we call up Mickey Merritt, urban forester with the Texas A&M Forest Service. We’d been concerned about the trees around the city. The weather has been confusing: freezing one day, summer weather the next, then cold again. There seemed to be a lot of empty trees and leaves on the ground.
Merritt said he was concerned too. Despite the freeze in early January, it’s been “a fairly warm winter,” he pointed out. “That’s why we’re having trees bud out and starting to flower.”
“If we have a deep freeze, we could have a lot of problems.”
The freeze in early January was not much of an issue for native trees, he said. The freeze a couple of years ago took out many of the non-natives, he pointed out.
But, he added, “I just hope we don’t get a deep freeze. Around freezing I would not worry. What I would be concerned about is if it gets down into the mid-20s.”
SC
Flood Planning Update
Are Flood Planners Ignoring Legal Requirement To Consider Environmental Impact?
Stormwater Tunnel Inlets: No Environmental Impact On Streams, Says Flood Control
Related: Stormwater Tunnel on Buffalo Bayou Will Not Prevent Flooding
Improving Flood Risk Knowledge. Proposing Solutions
Bayou City Sitrep: What’s Been Happening
Dec. 23, 2022
Update Dec. 24: President Biden signs authorization for Galveston Bay Surge Protection Plan. Funding not included.
Freeze? Drought? Holiday lights went out? Flood planning goes on.
A regional planning group has voted to send the state a flood plan while expressing concern that failure to assess its environmental impacts could be illegal.
Members of the San Jacinto Regional Flood Planning Group noted at a recent meeting that there were numerous public comments objecting to the environmental impact of projects included in the plan. Many were lodged against channelizing natural streams, among them wooded Spring Creek on the northern border of Harris County, parts of which are under conservation easement.
Conservation easements are actually a flood management strategy. Channelization, or dredging, altering, and straightening streams can increase downstream flood risk and lead to erosion, sedimentation, maintenance, and environmental issues. (pp. 154-155)
Criticisms also focused on the abundance of structural or engineering projects compared to nature-based projects and nonstructural strategies. The state’s technical guidelines require a balance of structural and non-structural projects, with an emphasis on natural systems and functions. (pp 87-88)
Nature-based approaches, or green stormwater infrastructure, slow and absorb stormwater runoff before it enters our pipes and streams. (Also improves property values, cleans the air and water, improves biodiversity, makes life better, and more.) Scientific studies have shown that nature-based flood management – using trees, plants, wetlands, prairies, etc. — is cheaper and more effective than structural engineered projects. (See here and here.) And here is Save Buffalo Bayou’s previous comment to the flood planning group outlining what other cities and states are doing in this regard.
The planning group, known as Region 6, is one of fifteen localized groups set up by the Texas Water Development Board to develop continuing flood plans to be funded by the state. The regional plan includes numerous projects and strategies proposed by governmental or public entities. These are cities, counties, districts draining the watershed emptying into the San Jacinto River, an area extending from Galveston to Huntsville.
The group had not yet posted the final approved plan on its website as of publication time. The final plan is to be sent to the state board by Jan. 10, 2023. Here is a link to the meeting presentation.
Most of the comments received on the draft plan objected to the emphasis on structural or engineered projects, the lack of nature-based projects, and the failure to consider the impacts of proposed channelization of streams and coastal surge protection projects.
The planning committee’s general response to these complaints is that they are “not endorsing” but just “including” the projects in their plan.
However, group member Gene Fisseler pointed out at the recent meeting Dec. 8 that it was important to make sure that the group adhered to its statutory requirement to evaluate environmental impact under Ch. 362 of the Texas Administrative Code.
The group members approved changes to the plan, including adding four City of Houston projects in Kashmere Gardens, Fifth Ward, Sunnyside, and Pleasantville. (pp. 19-22) They discussed how to answer environmental concerns.
Here is an explanation of the draft flood plan before it was updated.
The next planning meeting is scheduled for Feb. 9, 2023. The next plan update is due July 14, 2023. There will be further opportunity for the public to comment, Megan Ingram of the Texas Water Development Board said at the hybrid meeting held at the Houston Advanced Research Center in the Woodlands. A recording of the meeting is here.
The flood plan is an ongoing project, to be updated every five years.
Reaction of Conservation and Environmental Groups
Conservation groups, including Bayou Land Conservancy and the Coastal Prairie Conservancy, as well as numerous individuals, objected to plans to strip, dredge, and channelize natural streams, including those under conservation easement, specifically Spring Creek. They urged the flood planners to drop the San Jacinto River Regional Watershed Master Drainage Plan which includes those plans.
A coalition of environmental groups, including Save Buffalo Bayou, urged the flood planning group and the US Army Corps of Engineers to reconsider the environmental impact of the $34 billion coastal barrier and gate system recently approved by the House of Representatives. The draft flood plan claimed there was no environmental impact from the Corps’ Galveston Bay Surge Protection plan (known as the Ike Dike). (p. 2050)
Breaking: Mayor Nominating New Houston Parks Board
Revealed: How to Apply
Dec. 5, 2022
Heard around Houston town: Mayor Sylvester Turner is nominating a new slate to the dilapidated and nearly defunct Houston Parks Board.
We’re talking about the public board, a local government corporation (see also here), which for years has been violating the Open Meetings Act. This has happened because the twenty members of the public board were also (or mostly) board members of the larger private Houston Parks Board foundation. So when the private board met in private it often had a quorum of the public board, which violated the law.
We have been calling for a new public board for over two years now. Most major cities in Texas and around the country avoid this problem by having two separate parks boards or commissions for oversight of parks and fundraising: a public board and a supporting private foundation. A public board would generally be composed of community activists, ecologists, etc. and the private board would be composed of the money people: investors, real estate developers, philanthropists, etc.
No Public Outreach. Who Will The Mayor Nominate? How to Apply
It seems the mayor and city council are now attempting to remedy this problem. However, there has been no public announcement, no public outreach or communication about it. We confirmed that this was happening with the mayor’s director of boards and commissions, Olivia Lee. She recommended that anyone interested in joining the public board apply through the City’s boards and commissions website. Persuading your city council representative to recommend you also helps to become a member of the public board, according to Lee’s predecessor, Maria Montes.
At the moment there are 5 vacancies, 10 expired terms, and 5 terms about to expire on the 20-member public board. Apparently the mayor will nominate a new slate before the end of the year. Houston City Council must approve the nominations.
What Does the Public Parks Board Do?
Parks board members are appointed to three-year terms, though they can remain in their position until a new member is appointed. According to the board’s charter and bylaws (p. 2), the board is generally charged with acquiring or improving land and buildings for public parks, playgrounds, and museums; reviewing plans and advising the mayor and city council on expenditure of city funds and parks department matters, soliciting gifts of money or land, etc.
Other Cities Televise Parks Board Meetings
We learned about the plan to nominate a new slate at a rare public meeting of the public board early on a weekday morning in October. The meeting was held in a tiny room in a building on the grounds of the lovely 16-acre Wiess Park just west of Memorial Park at 300 N. Post Oak Lane. Only recently has the private board been posting notices of the public meetings on its website. (Previously a small printed notice was posted downtown on the bulletin board at City Hall shortly before a meeting.) But clearly the public board was not expecting members of the public on this workday. There was hardly space in the crowded room for board members to attend, much less anyone else.
Nevertheless it was an interesting meeting, with comments from Kenneth Allen, director of Houston’s Parks and Recreation Department, and from board members about the $60 million bond issue for city parks later approved by Houston voters, about nature preserves in city parks, about the lack of access to parks in denser residential areas, and other issues.
Here is the public notice of the meeting. And here is the financial audit approved at the meeting.
Let’s hope the new board will truly become a public board, transparent and responsive. Maybe even televise its meetings like they do in other cities.
SC
Save Buffalo Bayou Needs Your Support
Nov. 22, 2022
Save Buffalo Bayou is a unique voice advocating for our streams and forests, for enlightened flood risk management, and for nature in the city. There are many environmental groups doing excellent work in the Harris County region, and we do our best to complement, amplify, and publicize what they do as well. Through our journalism, we try to educate the public and public officials
We need your financial support now. Use the Donate button to the right of the page. But you can also send a check. See below.
Our budget is small. It goes a long way. We rarely ask for money. But in order to maintain our public charity status, the IRS requires that we have a substantial amount of small individual donations. We’d rather not have to spend any time raising funds, a burden for a small organization. But before the end of the year, we need to raise at least $10,000 in gifts smaller than $1,000. Of course, Save Buffalo Bayou is a 501c3 nonprofit and donations are tax-deductible.
Why Should You Support Save Buffalo Bayou?
In the past year we have published over a dozen major reports on nature-based flood management, exposure of damaging and outdated practices by local agencies and organizations and private engineering contractors; explaining development of local, regional, state and federal flood management plans, and describing what other cities and states are doing to reduce flooding and flood risk, as well as exposing long-term violations of the Open Meetings Act by the Houston Parks Board LGC.
We have done major investigative research, including public information requests, into at least nine different project areas related to flooding, flood risk management, and stream channel maintenance.
We have participated in over 100 meetings of various governmental agencies, public and private groups concerning flood management and planning, the environment, and nature in the city.
We have given several public presentations or participated in panel discussions about Buffalo Bayou, understanding rivers, and modern flood management.
And more.
So please think about a gift to Save Buffalo Bayou. We prefer checks because PayPal takes some three percent of all donations. Send checks to Save Buffalo Bayou at 3614 Montrose #706, Houston, TX 77006. But it’s true that PayPal is quicker and easier.
Thank you for your support.
SC
Fall on the Bayou
A Misty Sunrise on that Bend in Buffalo Bayou
And the Benefits of Wildness in the City
Nov. 21, 2022
It was a beautiful misty morning on Buffalo Bayou in Houston’s Memorial Park. Technically it was fall but our seasons are not obvious in Houston. Unless it’s hurricane season or an ice storm perhaps. Definitely winter if there’s ice hanging from the drooping telephone wires and people are trapped in their homes.
Perhaps we should name our seasons after what actually happens, as the Egyptians did.
We were traipsing through the forbidden woods just after dawn, talking too much probably, headed towards the high bank overlooking that bend in the river we’ve been documenting throughout the seasons for over eight years now. Jim Olive, our boss photographer, was not available so the assistant photog was leading the way down the shadowy dirt path, accompanied by a backup assistant.
The big woods were forbidden, still, because the private conservancy that manages our public park decided several years ago for dubious reasons that the paths through these lovely woods were closed, throwing up threatening signs, wire fencing, and piles of cut tree trunks and branches.
In rebellious response, someone recently had blocked out the “Not” on the “Do Not Enter” sign. The simple path, as always, was well maintained by anonymous volunteers and well used by walkers, runners, and other creatures.
Stormwater Tunnel on Buffalo Bayou Will Not Prevent Flooding
Plans Still Evolving
Comments and Questions
Please note that the Houston Chronicle has published a highly useful explanation of the coastal protection plan for Galveston Bay known as the Ike Dike. Unfortunately the paper has not figured out how to market to nonsubscribers.
Oct. 2, 2022
Large stormwater tunnels will likely not prevent flooding on Buffalo Bayou, according to the recent report from the Harris County Flood Control District.
Tunnels draining the federal flood control dams on upper Buffalo Bayou would not even be adequate to prevent a catastrophic overtopping of the dams or flooding of properties behind the reservoirs if a Harvey-like storm parked on top of the reservoirs, according to an engineering analysis prepared for Houston Stronger, a west Houston-based group formed in the wake of Harvey in 2017.
The Harris County Flood Control District is considering a $30 billion, 133-mile system of eight large-diameter stormwater tunnels to manage flood risk in the county. The district issued its Phase 2 feasibility report at the end of March and updated it in September. The district has been holding public meetings and taking public comments in preparation for the next phase of analysis to begin in the spring.
Limited Capacity
The probability that the proposed Buffalo Bayou tunnel would not prevent flooding downstream on the bayou is based on its limited capacity. The main tunnel would connect to two short 40-foot diameter tunnels, less than two miles long, draining Addicks and Barker dams far upstream. They would have a combined capacity of 11,600 cubic feet per second (cfs). This would drain into the much longer 40-foot diameter bayou tunnel which would have a capacity of only 12,240 cubic feet per second. Inlets or intakes draining the entire bayou downstream would have to be closed to accommodate stormwater flowing into the main tunnel from the two dams. The main tunnel would traverse the city deep underground for some 22 miles all the way to the ship channel east of downtown. (p. 127) (See also p. 1130)
That means that Buffalo Bayou would still flood because the bayou floods from urban rain runoff below the dams even when the dam floodgates are closed and no stormwater is draining out of the reservoirs. (See also here.)
Improving Flood Risk Knowledge. Proposing Solutions
A Draft Flood Plan for the Region
Key Finding: Lack of Information
Emphasis on Preparedness
How to Manage Development
Public Meeting in-person, Sept. 27, 5:30-7:30 pm. White Oak Conference Center, 7603 Antoine
Public Meeting virtual online, Sept. 29, 5:30-7:30 pm
Public Comment through Oct. 27
Public Comment through Sept. 30 on the Harris County Flood Control District’s proposal for county-wide stormwater tunnels
Sept. 26, 2022
Harris County does not have adequate information about where and how the county floods.
In fact, the entire watershed draining into the San Jacinto River does not have adequate information about flooding. This watershed includes Harris and parts or all of ten other counties from Galveston in the south to Huntsville in the north.
But the Harris County Flood Control District is working on it. (Back in 2017 the Army Corps of Engineers was going to work on it too and that work would have been done by now. But that project was changed.)
The lack of information is just one of the findings (p. 30) of a state-sponsored flood planning group which has been meeting and gathering information for nearly two years. The group of mostly citizen volunteers represent a variety of interests, including small business, agriculture, the environment, municipalities, water and electric utilities, the public, and more. Aided by public officials and the engineering firm Freese and Nichols, the group, known as the San Jacinto Regional Flood Planning Group or Region 6, recently released a massive draft report, which will be evaluated by the Texas Water Development Board, incorporated into a state flood plan, and sent to the state legislature in 2024 for possible funding. The state flood plan is to be updated every five years.
Managing Development. Being Prepared
The population of the San Jacinto region is expected to grow by one-third by 2050, and “one of the largest challenges” associated with this population increase, according to the report, is “determining how to manage development responsibly and continue to preserve the region’s natural resources.” (p. 24)
Increasing flood preparedness and improving flood management regulations and ordinances are also among the top priorities detailed in the report. (pp. 154 and 172)
The public can comment until Oct. 27 on the draft report, which is 302-pages long plus thousands of pages of appendices and maps and stuff. There are also two public meetings about the plan this week, one in-person Tuesday, Sept. 27, and the second virtual on Thursday, Sept. 29.
Big Bottom-Up Flood Planning Effort
The regional group is one of fifteen established by the state legislature in 2019. Based on the watersheds of the major rivers draining the state, the groups operate under the technical guidance of the Texas Water Development Board.
The purpose of the entire project is to “improve flood risk knowledge and propose solutions,” according to James Bronikowski, manager of regional flood planning for the state board. The ongoing effort is “intended to be a transparent process which relies on public input,” though based on the number of website responses and attendance at public meetings, public input appears to have been modest so far. (p. 295)
A Variety of Potential Flood Risk Reduction Actions, Nature-Based, Expanded Benefit
Of the fifteen watershed planning regions, San Jacinto is the second smallest region but the most densely populated, with twice the population density of any other region. Harris County has the most people at risk of major flooding. (p. 82) The 5,089-square mile region also includes some 3,173 square miles of farming, forestry, and ranch land, mostly forestry and ranching. (p. 56)
The draft report identifies 650 potential actions that could help reduce flood risk in the region. These are divided into three groups: 1. evaluations or studies, 2. strategies or plans, and 3. actual projects, both structural and non-structural, though sometimes the difference between strategies and projects is unclear. These “actions” are largely if not entirely existing projects planned by local municipalities, counties, or districts. The basis for assessing these actions included high need and existing risk to critical facilities, no adverse impact, quantifiable flood risk reduction, and regional benefit. (p. 32)
Incorporating nature-based practices in at least 90 percent of strategies and projects is a long-term (30-year) goal. (p. 30)
The report also expanded the traditional but controversial benefit-cost ratio, which tended to favor expensive properties. (p. 160) Projects and strategies can or should have other benefits like “public uplift, public education, low impact development features, and environmental benefits.” (p. 163)
Summer on the Bend
On Buffalo Bayou in Memorial Park
Plus Land Bridges For Publicity, Not Necessary For Wildlife
July 10, 2022
There was an occasional surprise smell of mushrooms on the dirt path through the tangled woods on this early morning. Crows laughed and gossiped in the treetops. Cardinals and wrens flirted back and forth high in the blue sky. Down low there was an annoyed hissing and rapid rustling and hustling away in the crispy fallen leaves.
It was summer and time for our seasonal photograph of the Bend in the River in Houston’s great Memorial Park. But Big Jim, our devoted photographer, naturalist, and conservationist, was not in town, so it fell to the assistant to take the shot. We’ve been documenting the same bend in Buffalo Bayou throughout the seasons for the past eight years.
The Memorial Park Conservancy, preoccupied with bulldozing trees, pouring concrete, and hanging name plates, does its best to block access to this wild and peaceful southeastern section of our beloved people’s Memorial Park, throwing up wire fencing, tree limbs, and warning signs. But the simple, narrow paths are well-trodden and maintained by anonymous volunteers. Someone has restored the wood handle on the rope swing used by the adventurous to fly across the lovely, shaded creek that drains the center of the park. Further downstream someone else has hung a small rubber swing on the bayou bank.
There is a long Houston tradition of swings over the bayou, of course, thanks to the strong, gracious trees that grow near the sloping banks. Historically this was a thrill mainly available to those privileged to grow up in upscale neighborhoods on one of the only local bayous that hadn’t been stripped of its trees and straightened in misguided and counterproductive flood control projects. But Memorial Park belongs to everyone, and for many years there was a knotted rope swing hanging from the great arm of the ancient Southern Magnolia that still stands on the bank even further downstream. The rope disappeared years ago, and the massive tree is looking somewhat haggard. One of the world’s oldest plants, there are few magnolias left in the wild. This Magnolia grandiflora could be 200 years old. Could have been there when the great landscape architect Frederick Law Olmsted passed through, noting the beauty and perfume of the magnolias on Buffalo Bayou. (p. 29)
Here’s a short video of the woods and the bayou taken from the bank, along with a glimpse of the sandy creek flowing nearby.
Deep Diving Into Flooding
Flood Control Looking at Countywide System of Flood Tunnels
System Could Be One of Largest in the World
- Tunnel Drains Would Take 10 Acres of Memorial Park, 14 in T. Hershey Park
- Buffalo Bayou Tunnel Longest, Most Expensive, Longest Time to Build
- Public Comment Encouraged Through Sept. 30
July 5, 2022
Updated July 6 with question about total acreage required for the tunnels.
It’s difficult to think about flooding during record heat and drought, when it’s too hot to go outside, the roads are melting and water lines are bursting. And when you do go outside your cell phone shuts down and burns up in your hand and the utility poles stink of toxic creosote and the shadeless, empty concrete parking lot radiates like a stovetop and scorches your face. And it’s not even the hottest time of the year yet.
But maybe there’s a way to think about all that and flooding at the same time.
The Harris County Flood Control District is thinking big. They are looking at digging a $30 billion, 133-mile system of 8 large underground tunnels to drain stormwater out of our bayous and streams anytime it rains enough to, say, push water levels over the ordinary high flow. The tunnels would also have the potential to collect rain runoff from neighborhoods and streets.
The scope of the project, the result of Phase 2 of the tunnel study, was announced during a public meeting in June. The details are contained in a $2.5 million report conducted for Flood Control by the global engineering firm Black and Veatch. It’s 1,860 pages, which is why it’s taken us so long to explain it. Sorry.
If built, the ambitious project might just be the largest stormwater tunnel system in the country, if not the world.
However, one can’t help but wonder about the environmental impact and unintended consequences of regularly siphoning flow from our streams, particularly in Buffalo Bayou. There are sediment (pp. 1836-1848), maintenance and water quality issues to explore. Mosquitoes. Muck. Ground faults, leaking oil tanks, wells, pipelines, bridge and building support structures underground, the impact and operation of the outfalls. (p. 191) Drought and shrinking, buckling soils. (p. 12) And what if a heating climate changes rainfall patterns?
The Houston Climate Impact Assessment predicts a hotter Houston climate (p. 48), longer and hotter summers (pp. 31-32) with little change in annual rainfall. (p. 37) However, extreme precipitation events are expected to increase (p. 42) as is the risk of drought. (p. 43) More rainfall all at once and less rainfall for longer periods. But where in the Houston region this extreme rain will fall is difficult to predict. (p. 47)
The Tunnel System
The benefits of a stormwater tunnel system, according to Flood Control, include using less total land compared to the district’s usual methods, presumably for achieving the same level of reduced flood risk. Total land use for the proposed tunnels is 34 acres, compared to 377 acres for “channel improvements,” 12,882 acres for stormwater detention basins, and 3,145 acres for buying out homes and properties in flood-prone areas, according to a presentation by Scott Elmer, assistant director of operations for Flood Control, during the public meeting last month.
Update: It’s unclear how Flood Control calculates the land use for the tunnels since the 10 shafts along the route of the Buffalo Bayou tunnel alone require over 76 acres of mostly wooded land, including wetlands. (p. 960)
Flood tunnels also would be faster to construct “than multiple traditional projects of equivalent combined benefit,” said Elmer.
Note that the land use comparison doesn’t include prairies, wetlands, forested parks or undeveloped greenspace, street trees, conversion of parking lots, rooftops, and lawns or other “sponge city” approaches with multiple co-benefits, in addition to reducing flooding, like reducing urban heating (which also attracts storms) and global warming, increasing healthiness, economic activity, and the attractiveness of our urban environment. Could be a worthwhile alternative investigation.
The 8 concrete tunnels would be 30-40 feet wide, some 80 to 180 feet underground (p. 1104) with 39-140 feet of earth covering the top of the tunnel. (p. 19) Between 8.2 and 24.5 miles long, they would be constructed starting shallow and getting deeper as they approach the point where they would discharge the stormwater. Most would discharge into (p. 70) Buffalo Bayou east of downtown, into the Houston ship channel below the turning basin, or, in the case of the Cypress Creek tunnel, into Spring Creek (p. 92). The Sims Bayou tunnel would empty into Sims Bayou near Milby Park. (p. 94)
Most would operate by gravity, though pumps would be required to pump out water between storms and prevent accumulation of sediment. (p. 69) Even though Houston is famously flat (excluding its many sloping ravines, gullies, and creeks), there is a 240-foot drop in elevation from the highest point (Hockley Mound in northwest Harris County) to Galveston Bay. (p. 37) Which is why our rivers and streams drain that way.
Though the Phase 2 report frequently refers to 4 tunnels selected for further study, Flood Control’s Elmer confirmed in an email that all 8 tunnel concepts, potentially benefiting 11 of the 23 watersheds in Harris County, are being investigated in the next phase of the process.
Tunnels could be located in these watersheds: Brays, Buffalo (including Addicks and Barker), Clear Creek, Berry and Vince; Greens, Halls and Hunting; Halls and Hunting; Little Cypress Creek-Cypress Creek, Sims, and White Oak. (p. 17) However, further study will be conducted during Phase 3, which is to start in Spring 2023. The Phase 3 study will be funded with $20 million from the 2018 Harris County flood bond program and is expected to take three years.
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