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.”

The purpose of destroying forest to dig out detention basins next to Buffalo Bayou in west Houston is to allow the City of Houston to drain more water from city streets into the bayou sometime in the future. This is the so-called “no-rise” requirement enforced by the Federal Emergency Management Agency (FEMA). To protect us from increased flood risk, FEMA requires that the City and everyone else prove that development within designated floodplains does not add to the flow in the bayou.

“We think there are advantages for the future when comes to drainage,” said Lopez.

Currently the City has no plans to drain more stormwater into the bayou, said Tommy Artz of the City of Houston Public Works Department’s Interagency Coordination Section. But the City has already paid $1 million to Flood Control to purchase some 30 acre-feet of the planned stormwater detention for future projects, said Artz

Some residents in neighborhoods near large commercial districts and Interstate 10 on the north side of the bayou are pushing for more drainage into the bayou. A representative of their neighborhood coalition declined to comment.

Artz explained that it was cheaper to purchase the detention from Flood Control than to buy land to build and maintain detention basins or install large underground culverts for temporarily holding stormwater. He described the purchase as a “bargain.”

Lopez explained that the flood control district already owns the land next to the bayou in Terry Hershey Park and has always planned to use it for flood management projects.

He said he believed that the agency planned to try to leave trees on the banks. “Trees help us prevent erosion,” he said.

Flood Control is planning three initial basins on the south bank of the bayou between North Eldridge Parkway and Dairy Ashford Road. Construction is to begin within weeks. The basins will briefly hold about 90 acre-feet of overflow from the bayou when it floods before allowing it to drain back into the bayou.

The district has already spent millions on the south bank linear detention basin project in the past decade, including paying various engineering firms for vegetation surveys and design. Lecon, Inc. has the $1.8 million contract to construct the initial three basins.

Proposed overflow detention basins along south bank of Buffalo Bayou in Terry Hershey Park. Image courtesy of the Harris County Flood Control District.

Area of proposed basins on wooded south bank of Terry Hershey Park on Oct. 28, 2017. Green space on north bank is grassy park with white line of sidewalk where trees were removed for detention decades ago. Buffalo Bayou is thin gray-green line between trees.

Decimation of Our Urban Forests

The tree removal project comes at a time when Houston’s remaining urban forests are being decimated. Hundreds of trees have already been felled in Memorial Park, our once-great public forest in the middle of the city, as part of a $200-300 million landscape plan for the park. Hundreds more, including towering pines, are already tagged for removal to make way for an artificial land bridge over Memorial Drive. More trees are being felled for the $13.5 million remake of the park’s popular public golf course into a professional tournament course, the plans for which city officials refuse to reveal. And then there are the numerous big trees that will be cleared in order to plant a monoculture of young pines in rigid rows on the west side of the park – a planned memorial to those who died in World War I. Planting a single species of trees in regimented rows, however, is a prime example of the wrong thing to do in the midst of an alarming loss of the biodiversity that supports life. Also it’s ugly and unnatural.

Mature pines recently felled in the forest of Memorial Park north of Memorial Drive are only a few of the hundreds of trees being removed as part of the $200-300 million landscaping plan. Photo by SC Jan. 24, 2019

Years ago the Harris County Flood Control District, in collaboration with the Buffalo Bayou Partnership, stripped trees and scraped vegetation from the banks of Buffalo Bayou in Buffalo Bayou Park downstream from the Shepherd Bridge. The result has been a disaster, with continuous costly repairs to collapsing banks and sidewalks.

The flood control district continues its decades-long practice of cutting and bulldozing trees on streams, oftentimes merely to provide access for bulldozers and other heavy equipment to the bank. Most recently, for example, Save Buffalo Bayou documented piles of large trees felled by the district’s contractor along Langham Creek in Addicks Reservoir. (See photo below.)

The district is legally responsible for the “conservation of forests” according to its 1937 founding charter. (P. 1)

Trees cut by Harris County Flood Control along the natural channel of Langham Creek in Addicks Reservoir. Photo Dec. 9, 2018, by SC

The Background

In the wake of Hurricane Harvey, the Harris County Flood Control District revived a controversial plan to capture flow out of the bayou with a series of shallow basins on the forested south bank of the stream in Terry Hershey Park. Residents, conservationists, and others, banding together as Save Our Forest, have been fighting to preserve the trees on the south bank since at least 2010. However, many of those forest activists were among the thousands who flooded on upper Buffalo Bayou during Harvey. With homes destroyed and health damaged, their ability to oppose the project has been weakened.

“I feel like they are pushing this thing now when they know people are too distracted to resist them,” said one distraught resident.

Terry Hershey Park, run by Harris County Precinct 3, occupies about 500 acres of land along some six miles of bayou that the district purchased from the federal government in the Sixties. 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.)

Allow Bayou to Increase Capacity Naturally and For Free

The straightened bayou in Terry Hershey Park, like all rivers and streams, continues to try to restore its natural bends or meanders and recover its former length and capacity. Allowing it to do so would in fact probably be the easiest and cheapest stormwater management project. Restoring meanders to channelized streams is modern practice. “Restoring meanders to rivers that have been straightened … increases the in-stream storage capacity and slows the downstream propagation of the flood peak, thereby decreasing downstream flood risk …,” reports the nonprofit International Rivers.  (p. 11)

The park is named for legendary environmentalist Terry Hershey, who in the Sixties and Seventies organized landowners, conservationists, garden club members, and influential politicians, among many others, to protect Buffalo Bayou from being stripped, straightened, and covered in concrete.

Learn more about Houston and trees from the City of Houston’s Office of Sustainability.

What to do: Contact Harris County Precinct Three Commissioner Steve Radack. He’s in charge.

SC

Not So Secret Alligator Snapping Turtles

Dec. 12, 2018

So recently the Chronicle blew the secret that there are giant alligator snapping turtles in Buffalo Bayou.

But apparently it wasn’t much of a secret. Turns out that lots of people already knew about alligator snappers in the bayou and elsewhere. We posted the article on our Facebook page, and we were bombarded with stories and photos of close encounters with the big snappers over the years—as near as back yard ravines.

Last year volunteers with Save Buffalo Bayou participated in this long-term project sponsored by the Turtle Survival Alliance to tag and track the massive turtles, the operation described by the Chronicle’s Molly Glentzer. The turtles, the largest freshwater turtles in the world, are designated a threatened species by the State of Texas, which means it is against the law to capture, trap, take, or kill them, or even think about doing that. They happen to be an ingredient in classic New Orleans-style turtle soup and therefore subject to poaching, which continues in the state, even though these days alligator snappers for cooking are farm-raised. We were asked to keep quiet about the turtles until the turtle scientists had a better idea of how they were doing here. Apparently they are doing pretty well.

The young researchers from the Turtle Survival Alliance had a special permit from Texas Parks and Wildlife to trap the turtles for research, checking their health, population, and movement. They needed help setting the traps (which involved wading into the water), lifting the monster turtles out of the traps, photographing, measuring, and tagging the ancient creatures, or chelonians, as senior scientist Jordan Gray referred to them; and then putting them back in the water again. All the while avoiding their massive jaws.

Alligator snapping turtle trapped for research on Buffalo Bayou. Note pink tongue used to attract prey into jaws. Photo by Jim Olive, February 10, 2017

The big turtles are among at least nine different types of turtles noted in Buffalo Bayou by avid kayaker, fisheries biologist, and environmental lawyer Bruce Bodson, who is also a member of Save Buffalo Bayou’s advisory board and executive director of Lower Brazos Riverwatch.

Since we’re telling you about the alligator snappers, we might as well mention that Bruce has seen bull sharks in the bayou as far upstream as Highway 6. (Maybe we shouldn’t tell. … Too late.)

Also swimming around in the muddy bayou waters is the prehistoric alligator gar dating from the time of the dinosaurs. These scaly creatures can get to be more than ten feet long and over 300 pounds, living to be more than 50 years old. Alligator gar, now respected for their ability to control invasive fish like carp, are also eaten, and there was not too long ago a commercial fishery for the gar down the coast. One can still find alligator gar meat for sale in some Texas fish shops, along with alligator meat, presumably farm-raised.

And yes, we do have alligators in Buffalo Bayou. Also catfish, which can grow to more than forty pounds. Amazing that there is room for all these massive creatures to move about in the shallow waters of the bayou. And they may have been doing that—the snappers, gars, and alligators—since before the 12,000-18,000-year-old bayou was a bayou, back when it was a part of the Brazos River.

Of course, there are a lot of smaller creatures, like beaver, river otter, snakes, etc. swimming in the bayou. The Rio Grande Cichlid (perch), a transplanted native, has somehow made its into the bayou. We’ve even had a report of an eel. And some very weird invasives, like Plecostomus, a gaudy, spotted aquarium fish known as the armored catfish.

Houston Strong!

Don’t feed the alligators in Buffalo Bayou.

Federal Project in Late Forties Reduced Bayou Capacity Upstream

October 29, 2018

(Update Nov.13, 2018: Harris County Commissioners’ Court approved a $350,000 contract to study “high-flow bypasses” through meanders on Buffalo Bayou as well as the impact of existing bridges.)

(Update Oct. 20, 2019: Raising Bridges, Building Meander Bypasses on Buffalo Bayou Doesn’t Reduce Flooding, Study Says)

By the early morning of Aug. 28, 2017, after about thirty hours of record heavy rains from Hurricane Harvey, storm runoff was rising so fast in the two federal reservoirs in west Houston that the Corps of Engineers feared the water would overflow the aging earthen dams. They made the unprecedented decision to open the dam floodgates, slowly at first and then, in the following days, much wider, as stormwater did indeed begin to spill around the northern end of Addicks Dam north of Interstate 10.

For most people living and working on Buffalo Bayou, the peak of the flooding had already passed on Sunday, Aug. 27, when the floodgates were still closed. That Sunday storm runoff draining from the paved and built city into the bayou below the dams sent anywhere from two feet to eight feet or more into homes and other structures built on or near the banks.

But when the dam floodgates were opened in the first hours of Monday, roaring floodwaters pouring out of the dams spread out and inundated neighborhoods built on the bayou’s floodplain below the dams for more than six miles to just below Beltway 8 (West Belt). Many of these homes had not flooded earlier.

The horrific flow through the open floodgates eventually reached more than 16,000 cubic feet per second (cfs). For much of Buffalo Bayou in west Houston flood stage is around 6,000-7,500 cfs.

As a result, many more homes and other structures flooded on the upstream stretch of Buffalo Bayou between the federal dams and Beltway 8 than downstream of the beltway. (Homes built in the reservoir flood pools behind the dams also flooded, but that’s another story.)

Map of Harvey flood damage claims on Buffalo Bayou made to the Federal Emergency Management Agency. Barker Reservoir, south of Interstate 10, and Addicks Reservoir, north of the highway, are the green spaces on the left. Courtesy of Matthew Berg, Simfero Consultants

Blaming the Bayou. “Kinks” and “Bottlenecks” Downstream

This six-mile stretch of the bayou upstream of the beltway was straightened and shortened by the Corps of Engineers more than seventy years ago. The bayou downstream of the beltway remains a meandering stream, largely unchannelized, twisting and turning its way nearly to Shepherd Drive. Below Shepherd the bayou was stripped and channelized in Buffalo Bayou Park by the Corps in the Fifties. From there it flows along a heavily altered route through downtown, eventually becoming the Houston Ship Channel.

In the wake of this disastrous flooding upstream of the beltway, distraught and shell-shocked property owners, many of them without flood insurance and dealing with severe losses, have been blaming the “kinks” and “bottlenecks” in the meandering bayou below Beltway 8 for flooding their homes. The belief is that the meandering bayou constricted the flow and caused water to backup and flood property upstream. The common complaint is that the bayou downstream is too narrow and is “like a hose” that gets a “kink” in it, causing the water to stop and back up.

Many, including developers and other business interests in west Houston, are calling for the meandering, relatively natural bayou downstream to be deepened and widened to accommodate double or triple the volume of flowing water—something close to the 16,000-plus cfs that occurred during Harvey.

Neighborhood activists upstream have also proposed a plan for large concrete culverts to be dug into the banks, presumably under streets and homes, in order to bypass the meanders downstream. In response to community pressure, the recent Harris County flood bond election included a proposal to spend $500,000 to study these “high flow bypasses,” “channel conveyance capacity” around Beltway 8, as well as bridges over Buffalo Bayou that may be obstructing floodwaters.

There are even calls for the trees to be cut down in Terry Hershey Park along the straightened channel upstream, as well as inside the flood-control reservoirs, Addicks and Barker, which are vast public parks. This theory is that trees take up storage space and block the flow.

Why Did More Structures Flood Upstream?

One only has to look at a map of house flooding as reported to the Federal Emergency Management Agency to determine that many more structures were flooded between the dams and the beltway than along the meandering bayou downstream.

But what was the reason for that?

A major cause is the straightening and channelizing of the upper bayou as well as a tributary creek done decades ago by the Corps of Engineers, according to a study done for Save Buffalo Bayou by hydrologist Matthew Berg. Of course, houses and other structures that flooded immediately below the dams weren’t there when the Corps straightened the bayou, shortening it and altering its course.

The Corps project cut the upstream capacity of the bayou in half, says Berg.

In addition, the floodplain surrounding the bayou upstream—the area onto which the excess water overflows—is much wider because it is lower in elevation, a result of long-term natural subsidence due to faults in the region, notes William Dupré, professor emeritus of geology in the Department of Earth and Atmospheric Sciences at the University of Houston.

See this study by Houston geologist Tom Helm, a board member of Save Buffalo Bayou, of the elevations and floodplain of Buffalo Bayou between Eldridge and Beltway 8.

“Downstream meanders are not causing the flooding upstream,” says Dupré.

Some History

Some seventy years ago the Corps of Engineers built two dams on the prairie west of Houston, then mostly farm and ranchland. The dams were to hold back floodwaters of then-forested streams that flow into upper Buffalo Bayou. Damming these tributaries and the bayou itself during heavy rains was supposed to protect the city of Houston downstream from flooding. The 18,000-year-old bayou, the city’s main waterway, runs for some fifty miles from its headwaters near Katy through Barker Reservoir and the center of the city, emptying into the San Jacinto River and Galveston Bay.

The Corps also stripped, straightened and shortened the bayou for more than six miles below the dams. They also stripped and straightened Langham Creek where it flows into Buffalo Bayou from Addicks Reservoir north of Interstate 10.

A comparison of the original meanders and the straightened channel of Buffalo Bayou flowing through Terry Hershey Park by geologist Tom Helm. Langham Creek is the squiggly white line in the woods on the upper left corner.

The idea was to make the water flow faster through the channelized creek and bayou so that the dam reservoirs could be emptied more quickly. The expansive reservoirs of the two federal dams were designed to be dry, remaining prairie and riparian woodlands. The creek and bayou flow freely through the dams, and the floodgates are closed only during storms. Emptying the reservoirs as quickly as possible is necessary to prepare for more rainfall and prevent the earthen dams from overflowing, a common cause of dam failure. The dams were not designed to hold water for long periods of time.

After the dams were built, the forested floodplains that remained alongside the bayou were thought to be protected from flooding. These natural floodplains, often sloping, traversed by small creeks and ravines, and shaded by tall oaks in the midst of the flat, open prairie, were developed into desirable residential neighborhoods, offices, hotels, apartments, businesses and parking lots, including behind the channelized stretch of the bayou, now Terry Hershey Park, where trees have since regrown.

Protecting the Meandering Bayou

But the Corps wasn’t finished. The plan was to do to the rest of Buffalo Bayou downstream what the Army engineers had done in the mid-Fifties and early Sixties to Brays and White Oak bayous: strip, straighten, and line it with concrete. Opposition from influential property owners and environmentalists stopped that project. Straightening and concreting natural waterways has since been mostly abandoned as a flood management practice because it increases flooding and water pollution and because of the high and continuing cost, both financially and ecologically. The focus of flood risk reduction now is on slowing the flow, managing flooding in place, making room for the river, and working with, rather than against, the natural functioning of a stream. In other words, stopping stormwater before it floods a stream.

Buffalo Bayou below what is now Beltway 8 remained a meandering stream lined with tall trees, most of it privately owned.

The Corps Project Reduced by Half the Capacity of the Upper Bayou 

But in straightening that upper six-mile section of the bayou, the Corps reduced by at least half the storage volume of the stream in that stretch. Removing the meanders shortened the stream. Shorter streams carry less water.

“The upper section in the old days held more than twice as much as today,” notes hydrologist Berg.

In addition, by straightening Langham Creek and aiming it almost directly into the channelized bayou, the Corps inadvertently made flooding worse for the future homes that would be built near the intersection of those two streams.

“Where two streams come together is the worst place to develop,” says Berg, referring to the point where the two streams meet north of the bayou and west of Eldridge Drive. “The two streams block each other at high flows.”

“This would be an awesome place for buyouts.”

FEMA flood damage claims at the confluence of upper Buffalo Bayou and Langham Creek from flooding after the floodgates were opened on the federal dams. Map by Matthew Berg, Simfero Consultants.

Meandering Bayou is Deeper, Wider, and Steeper

The straightened section of the bayou in Terry Hershey Park is not just shorter than it used to be. It’s also shallower and narrower than the meandering bayou below the beltway. Despite the apparently popular belief that the winding bayou downstream is narrower and constricting the flow, the fact is that the bayou below the beltway is much wider than upstream both at the channel bottom and from bank to bank across the top, according to Berg’s research.

The bayou also has a steeper slope downstream which causes the water to flow faster, says Berg.

“The Corps exchanged greater volume [in the shorter, straightened stretch] for shorter distance and steeper slope,” says Berg.

While some would argue that the increase in velocity in a straighter, shorter stream can make up for the loss of volume of a longer, winding stream, Berg notes that this tradeoff is not always so simple. “You really need to look at how a stream works along its entire length, not focus just on any one spot.”

Bayou Not Like A Hose. Meanders Not Causing Flooding Upstream

Meanders don’t cause the water to backup upstream, points out Dupré. Flooding tends to increase in the place where the meanders are, where the water slows, he explains.

“Straightening a channel to increase its velocity and lower its stage typically results in increased flooding downstream of the straightened channel, as that is where the water slows and stage rises.”

The bayou is not like a hose or pipe. It doesn’t have a top on it. Where it meets obstructions (“kinks”), it slows, rises to overflow the banks, and spreads out.

But “we don’t see this [downstream] because the channel gets deeper,” explains Dupré. And wider, says Berg. In fact, the bayou channel gets deeper and wider the farther downstream you go.

However, in general, straightening, shortening, increasing the velocity does tend to cause flooding downstream, confirms Dupré, as well as increasing erosion up and down the stream. And while the bayou downstream is deeper and wider, not all areas downstream were spared the full force of the stormwater shooting out of the straightened stretch upstream.

Neighborhoods just below Beltway 8, in particular the residences on Legend Lane, built on a large point forming the first large meander below the beltway, suffered a near direct hit from the floodwater rushing down the chute from Terry Hershey Park, as did the Briargrove Park neighborhood directly across the way. Subsidence in these neighborhoods, more than a foot between 1997 and 2017, has increased vulnerability to flooding here too, as it has upstream and elsewhere in the county, particularly the northwest.

Neighborhood activists downstream have suggested properties in these neighborhoods, particularly Legend Lane, are candidates for buyouts also.

Seeking Its Natural Channel

Another problem is that the altered bayou, like all flowing rivers and streams, tends to seek out its natural channel. (See also this study of the straightened sections of Buffalo Bayou by geologist Helm.) And in this case residences have been built on top of or very close to the historic path of the straightened bayou, directly in the path of the flooding river. Subdivisions have also been built on top of buried or filled creeks and ravines. Recognition that opening up these buried waterways can reduce flooding, among other benefits, has led to a global movement to “daylight” buried urban streams.

Dredging, Deepening, Widening. Making the Bayou More than Twice as Wide and Deep

Dredging, deepening and widening the bayou doesn’t work. Dredging makes flooding worse, and also causes the banks to collapse and the channel to fill with sediment as the bayou, like any stream, attempts to restore its dynamic equilibrium, a balance of flow, shape, slope, and movement of sediment. This constant natural adjustment by the bayou can lead to increased and continuing costly maintenance, and continuing ecological damage, when authorities continue to fight the river over its depth and width, and straightness.

But let’s imagine how deep and wide Buffalo Bayou would have to be in order to accommodate a flow of 16,000 cfs plus without overflowing its banks.

The bayou’s peak at Beltway 8 during the dam releases from Harvey was 71.22 feet on August 31, 2017, a flow of some 22,900 cfs. Let’s pretend that’s not going to happen again. We’ll deal only with official flood stages.  Flood stage on Buffalo Bayou at Beltway 8 is officially 62.2 feet, or a flow of some 8,000 cfs. But that’s flooding. We want to prevent flooding. Therefore, we would have to keep the flow below the so-called “action” stage: below 59 feet or below a flow of 6,400 cfs.

So in order to accommodate a flow of 16,000 cfs without the bayou overflowing its banks upstream and around Beltway 8, the bayou would have to be at least 2.5 times wider and deeper.

What to Do?

Well, making Buffalo Bayou more than twice as deep and wide is a ridiculously costly, physically impossible, and pointless idea. Among other issues, above about halfway up the bank, the land along Buffalo Bayou is mostly privately owned. Not going to work and not going to solve the problem anyway. So what is the solution?

Bypassing the meanders downstream with huge concrete culverts somehow buried under streets and houses is also wildly expensive and ecologically damaging. That’s not going to solve any problems and likely would create more problems. Among other issues, Berg notes that the bayou bottom and portions of the banks upstream of West Loop 610 are largely sand and highly erodible, and that the particular soils in this area are highly corrosive to both concrete and steel and would soon have to be replaced at great cost.

As for removing trees in an effort to speed up the flow, Berg points out that doing so would make the banks unstable as the roots of trees and other vegetation help hold the banks together, protecting against erosion and absorbing water.

However, redirecting several large stormwater outfalls that point directly across the stream, blocking the flow, might help. One example is the massive outfall at Beltway 8. Outfall pipes and boxes set at right angles to the channel are a violation of the flood control district’s design guidelines. (p. 111)

Making Room for the River

The solution is, in a way, the opposite of what some are calling for. Rather than dredging and channelizing the bayou downstream, the more practical and effective response is to allow the channelized stretch upstream to return to its meandering course.

Berg, Dupré, and many others (see here too) suggest the obvious: buying out properties in harm’s way, removing structures hopelessly deep in floodplains. Make room for the river. Let the bayou naturally restore its meanders, naturally lengthening the channel, creating greater capacity for the flow, slowing the flow to prevent flooding downstream while creating more room for the bayou to overflow.

“Any place you can put the bends back in is a good idea,” says Berg.

“I tend to be of the philosophy that we need to give room for the river,” says Dupré.

Graphic courtesy of the Biomimicry Institute

Addicks and Development of the Katy Prairie. Detention Requirements Not Working

Concerned residents also might want to focus on the source of all that water flooding their homes.

Both Berg and Dupré, along with numerous other experts, point out that the real problem is too much rain runoff flowing into Addicks Reservoir, and that continued development of the Katy Prairie, including the land around Cypress Creek north of the reservoir, is making the problem worse. The overflow from a flooding Cypress Creek ends up in an already overburdened Addicks Reservoir.

New subdivisions, malls, and roads on the prairie are increasing the flow of rainwater into the reservoir. Requirements that developers detain or hold back the runoff are not working, stated Christof Spieler, project manager for the Greater Houston Flood Mitigation Consortium, at a recent symposium on flooding. The consortium, in its April 2018 report, called for “[i]mprovements to Addicks and Barker, preservation and restoration of native prairie, and appropriate restrictions on new development” to address flooding. (p. 64)

Experts have for years been drawing attention to this problem. See this 2011 paper by Ronald Sass, fellow in global climate change at the Baker Institute and Wiess Professor of Natural Sciences emeritus at Rice University. Also in 2011 the Houston Sierra Club filed suit in federal court over the alleged failure of the Corps to analyze the flood-related impact on Addicks and Barker reservoirs of the Grand Parkway (Highway 99) and subsequent development of the Katy Prairie.

And yet, as Houston faces increasing and more frequent rains, county and city officials weekly continue to approve plats for new development on land that should be preserved as open space for stormwater detention. (See also here.)

“Development in west Houston is really a problem,” says Dupré, who suggests strengthening and deepening the reservoir to handle increased runoff, already “more water than [the dam] was planned for.” Also critical is addressing the overflow from Cypress Creek, he says.

“We need a more effective Addicks. It’s really a national disgrace,” says Dupré, pointing out that because of the consequence of failure to such a populous area, in 2010 Addicks and Barker dams were both listed among the six most dangerous federal dams in the United States.

“By the time water gets to the reservoirs, it’s already too late,” says Berg.

“We have to look at causes of the problems, not the symptoms.”

Green and Nature-Based Solutions Work Best

Fortunately, looking at the causes of and potential solutions to this flooding catastrophe seems to be happening.

Earlier in October Harris County Commissioners Court approved participation by the Harris County Flood Control District in a three-year study of Addicks and Barker Reservoirs and surrounding watersheds, including Buffalo Bayou and its tributaries. The Corps of Engineers will lead the study, and the $6 million cost will be paid with federal funds.

The Corps now has a mandate to “engineer with nature.” And the fact is that in the long run non-structural and nature-based solutions to flood risk—preserving and restoring the Katy Prairie, for instance—are more efficient and sustainable than “traditional structural measures” like dams, levees, and digging up bayous, as confirmed by a 2014 report from the American Society of Civil Engineers. (p. 27)

If we’re going to save the city by discouraging more development in west Houston, urban flooding experts like Sam Brody suggest that we will have to incentivize development elsewhere. If we can offer hundreds of millions in cash and tax breaks to Amazon, maybe we can find a way to make it attractive for developers to redevelop areas closer to town.

Rights, Responsibilities, and Flooding Your Neighbor

Sept. 20, 2018

Update Sept. 29, 2018: The National Oceanic and Atmospheric Administration has released new rainfall statistics and adjusted rainfall frequencies in Texas and Houston.

Updated Oct. 29, 2018, with recent photo of completed massive erosion control project on Buffalo Bayou.

Over the past several years, in the wake of extreme floods, we have received numerous complaints about damaging “erosion control” projects on the banks of Buffalo Bayou – projects damaging not only to the natural functioning and ecosystem of the bayou but also potentially to people living and working up and downstream of the projects.

Property owners bulldoze the banks, build massive retaining walls made of concrete block or sheet metal, dump piles of concrete construction debris into the bayou, strip and line the banks with concrete riprap.

This in addition to stripping the banks of trees and vegetation, reshaping the banks, irrigating, gouging out pathways, and landscaping with walkways and non-native flower gardens.

Do they have the right to do this? Is it a good idea? Who owns the bayou really? What permits are required, if any, to do these things?

And does the bayou itself have rights?

Did Retaining Wall Make Flooding Worse?

What happens if someone installs concrete riprap or a massive retaining wall that deflects the flow of the bayou away from their property and floods neighbors or damages public park property? This has happened repeatedly on Buffalo Bayou.

In one case, a large property owner in River Oaks, whose bank is likely affected by a large stormwater outfall directly across the way, installed a controversial concrete block wall along several hundred feet of bank in 2016, initially without a permit from the City of Houston. That armoring washed away during Harvey, and the property owner has now rebuilt the eroded bank, apparently dumping material into the channel, and installed a massive sheet metal wall that has alarmed residents across the bayou and elsewhere, threatening a narrow strip of land that the Houston Parks Board has been eyeing for a hike-and-bike trail.

Is that legal? Is it right? Does it work?

Shocker: The Port of Houston Owns Buffalo Bayou

This will come as a surprise to many people: The Port of Houston owns the submerged lands of Buffalo Bayou all the way from the bay to the headwaters. In 1927 the Texas State Legislature gave the Port of Houston “all the submerged lands lying and being situated under the waters of Buffalo Bayou, San Jacinto River, White Oak Bayou, Bray’s Bayou, Simms Bayou [sic], Vinces Bayou [sic], Hunting Bayou, Greens Bayou, Carpenters Bayou, Old River, Lost River, Goose Creek and Cedar Bayou, and all other streams within the authority tributary to the Houston Ship Channel, so far up said streams as the State may own same …  for public purposes and for the development of commerce only …” (See Sec. 5007.004)

Many people with property on Buffalo Bayou would think they own to the center line of the channel since the Harris County Appraisal District describes it that way and taxes it too.

In 1937 the legislature set up the Harris County Flood Control District and gave it the “right to make use of the bed and banks of the bayous, rivers, and streams lying within the District, subject to the prior right and authority of the [Port of Houston].” (See Section 9.) (The Flood Control District, as well as the City of Houston, also owns property outright on the banks of the bayou, along with easements.)

The state also made the flood control district responsible for the “conservation of forests,” (Sec. 4), as we have often pointed out, a responsibility the district routinely ignores. Forest, trees, vegetation, green space are vital resources for reducing stormwater runoff, absorbing water, protecting the banks, cleansing the water and air, and generally making us all safer and healthier.

What Are Submerged Lands?

The legal definition of submerged lands in Texas rivers is not exact. According to one source, streambeds are the soil between the “gradient boundary” on each stream bank. The state Supreme Court has defined the gradient boundary as “a gradient of the flowing water in the stream, [which] is located midway between the lower level of the flowing water in that just reaches the cut bank and the higher level of it that just does not overtop the cut bank.”

Normally the cut bank is the outside bend of a meander. But in this case the reference is “typically an alluvial bank along a straighter portion of the stream that is not actively eroding,” points out former assistant state attorney general Joe Riddell.

The state definition of submerged lands seems approximate to the definition of Ordinary High Water Mark used to delineate federal waters.  (See discussion below.) But generally the gradient boundary delineating stream bed ownership in Texas is slightly lower than the high water mark delineating federal waters, says Riddell, who worked in the natural resources division of the state attorney general’s office.

Who is Responsible?

Protection of our public streams and waterways, their adjacent floodplains and wetlands has two primary goals that concern us: ensuring the cleanliness of our waters and protecting us from flood risks by preventing any increase or rise in the existing flow of our natural drainage systems.

While physical ownership of the bed and banks may lie elsewhere, the federal government is responsible for protecting the water flowing through Buffalo Bayou and all navigable streams, their tributaries, floodplains, and connected wetlands. (See discussion of federal waters below.) Under the Clean Water Act, the Corps of Engineers has this enforcement responsibility, along with the Texas Commission on Environmental Quality (TCEQ). The TCEQ is responsible for certifying that any permits issued by the Corps for discharging dredged or fill material into federal waters, including the bayou, complies with state law.

In Texas a navigable stream is one that is useful even for pleasure paddling as well as, say, log flotation. The right of the public to access a navigable stream through public land is guaranteed in the Texas Constitution.

The water that flows through a navigable stream is held in trust for the public by the state of Texas.

The Corps, under the Rivers and Harbors Act, is also responsible for regulating any construction in or on the bayou and any dredging or filling of the channel.

Dredging, by the way, is destructive to a stream’s ecosystem, can even cause more flooding, and creates a need for continuing maintenance and more dredging.

Protecting Us from Increased Flooding

To protect us from increased flood risk, the Federal Emergency Management Agency (FEMA), through the National Flood Insurance Program, also requires that construction in the floodways and floodplains does not cause an increase or rise in the flow of our streams. Or at least, not very much.

A floodway is the main channel and deepest part of a river or stream and part of the floodplain. The floodplain itself extends beyond the channel and over a generally flat plain alongside the river. This is where, after Harvey, for instance, we saw massive accumulations of sediment deposited next to the bayou. That’s what flooding rivers do: overflow their banks, slow down, and drop out the sediment carried from upstream. It’s why the floodplains and valleys of rivers are so fertile. And also how rivers naturally build up their banks.

Sediment washed downstream by the powerful flow in the bayou during Harvey and collected in the dog park pond in Buffalo Bayou Park. Photo Dec. 22, 2017

FEMA, in order the minimize flood risk and regulate the insurance program, has more official definitions of “floodway” and “floodplain” and even several categories of floodplains based on 1. how much rain has to fall in order to flood those floodplains to a certain height (base flood elevation) and 2. how likely it is – considering the past record — that that much rain will fall.

A “floodway” officially defined by FEMA is “the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.”

The base flood is the 100-year flood, which virtually everyone agrees is a ridiculous term and confusing. Currently in Harris County this base flood is 13 inches of rain within a 24-hour period. Our flood management/drainage system/policies are built on trying to handle that much water.

However, this definition of a 100-year flood is obsolete, as noted by professors Phil Bedient and Jim Blackburn of Rice University’s Severe Storm Prediction, Education, and Evacuation from Disasters (SSPEED) Center. Recent research indicates that the base or 100-year flood locally should be at least 16-17 inches of rain in 24 hours if not more. (pp 10-12) (Update 9.29.18: The National Oceanic and Atmospheric Administration has released new rainfall statistics and frequencies for Houston and Texas. The new 100-year flood is now 18 inches in 24 hours.)

That means more rain is falling more often. Harvey in 2017 was technically a once-in-5,000-20,000-year-plus event. (p. 30)  The Memorial Day flood in 2015 and the Tax Day flood in 2016 were each 500-year floods. (p. 5)

The National Flood Insurance Program is a controversial taxpayer-funded program that subsidizes the reduced cost of private flood insurance premiums paid by renters, home and condo owners, and business owners in flood hazard areas in participating communities. Some people worry that providing cheap insurance to people who live in flood hazard areas encourages people to live there.

On the other hand, the insurance program does make an effort to discourage some activities that increase flooding.

Communities such as Houston and Harris County that participate in the program must “prohibit encroachments, including fill, new construction, substantial improvements, and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community …” (p. 6)

Here is an interactive map of current Harris County floodways and floodplains. Here is an interactive map from the City of Houston of Houston region floodways and floodplains. Note again that these maps are expected to change with new data to be released in October. Floodways and floodplains will get larger.

“We’re about to learn that … the new NOAA Atlas 14 data [will] translate into wider floodways and floodplains than we’ve been using in the past,” hydrologist Matthew Berg writes in an email. “In that case, some structures that were not held to floodway requirements under prior data will now be marked as in the floodway, realistically obstructing flow on a much more frequent basis.”

Rise/No Rise in Flood Waters

The engineering departments of the City of Houston and Harris County are responsible for making sure that construction and erosion control projects on the bayou and elsewhere meet this federal “no rise” requirement before issuing permits. Not that that’s easy to do when developers and property owners are wealthy, influential, and prominent members, even heads, of parks and other boards and commissions. City and county employees must also determine that projects have the proper approval from the TCEQ and the Corps.

Note that despite this “no rise” requirement, Harris County has the most and fastest rising streams in the state of Texas, according to a study by hydrologist Berg. These include Greens, Keegans, Langham Creek, White Oak Bayou, Cole Creek, Brickhouse Gully, Sims Bayou, Bear Creek, and Buffalo Bayou.  (pp. 22-23)

Apparently there are exceptions to the “no rise” requirement. (See page 6.) Or something is missing from the formula.

A 2013 report from the Association of State Floodplain Managers criticized the federal insurance program for allowing development in the floodways as long as the impact did not increase flood elevations by more than a foot.  (p. 4)  “Anything greater than zero is problematic” and “perpetuates an upward trend of increased flood damages,” noted the report (p. 16). “Small encroachments into a floodplain in and of themselves may have a negligible impact on flood elevations. However, the combined, incremental effects of human activity, referred to as cumulative impacts, can cause significant increases in flooding.” (p. 4)

Harris County allows zero increase in flood elevations in the floodway. “Under the conditions of obtaining a permit, no development or other encroachment, including fill, is allowed in a floodway which will result in any increase in the base flood elevations within the floodway during discharge of water of a base flood,” wrote Harris County Engineering Department Permits Manager Jesse Morales in an email.

However, Harris County only regulates construction activities in unincorporated areas of the county.

The City of Houston likewise prohibits any increase in base flood flow in the floodway.  “A floodway development can only be approved if the submitted engineering study shows that the development will result in 0.00 feet of rise in the base (100-year) flood elevation in the entire watershed,” writes Erin Jones, public information officer for the City of Houston Public Works Department, in an email. (Emphasis added.) Jones notes that this requirement is outlined in Ch. 19 of the city’s guidelines for development in the floodplain. (See pp. 45-47.)

It’s unclear whether a proposed project would have to show no increase in flood elevations for your neighbor immediately downstream or across the way.

That’s the Floodway. What about the Floodplain?

The floodplain managers’ report also noted the value of reserving floodplains adjacent to streams for floodwater overflow and storage. “The floodplain provides a valuable function by storing floodwaters. When fill or buildings are placed in the flood fringe, flood storage areas are lost and flood heights will increase because there is less room for the floodwaters.” (p. 22)

The report criticized the “hydraulic concept” that the flood insurance program uses to calculate the floodway. “The concept does not address hydrologic changes that could increase flood levels such as the loss of floodplain storage, increase in impervious surface, or changes in precipitation patterns.” Nor do the mapped flood zones consider “future land use conditions,” stated the report. (p. 22)

In addition, the floodplain managers’ report criticized the practice of allowing higher flood elevations caused by construction, constriction, or encroachment in the floodway to be balanced by increasing the flow conveyance, i.e.  reducing the roughness of the channel or floodplain. “Reducing roughness” (friction) means removing native vegetation and hardening the area. “However, this increases the flood flows velocities and increases the erosive properties of the flood flows. In addition, it removes valuable natural habitat in the floodplain,” stated the report. (p. 23) 

Both the City and the County require that construction in the floodplain (as opposed to the floodway itself) result generally in “no adverse impact,” though the concept is very broad. However, as outlined by the flood control district, it does include a general policy of not flooding your neighbor. (See p. 32)

“Our regulations address the concept of ‘no rise’ as no net fill in the floodplain,” writes Darrell Hahn of the Harris County Floodplain Management Office. (See p. 114)  “The Harris County Flood Control District addresses it as no adverse impact. It is policy that any project reviewed by the Harris County Flood Control District is required to prove that results are at most 0.0 rise in Base Flood Elevation.”

No net fill means you can’t bring in dirt, for instance, without excavating an equal amount of dirt because that will reduce the stormwater storage capacity of the property and increase runoff into the drainage system. Except that you can compensate or “mitigate” by excavating somewhere else.

The City has similar regulations for construction in the floodplain (see pp. 52-53) , though the city allows some increase in flow  (.5%) or loss (.5%) of capacity (conveyance) in the bayou and channels and natural streams crossing the floodplain, including prairies and forested areas. (See pp. 29-30)

Neither the City not the County addresses the usefulness or value of native trees and plants for controlling bank erosion and absorbing, slowing, and cleansing stormwater runoff. In fact, the flood control district actively discourages trees and vegetation along our waterways, known as riparian buffer, as impediments to conveyance. The district, apparently responding to public pressure for a manicured look, spends millions of dollars mowing the grass along our channels three times a year, which causes the grass to put its energy into growing upwards instead of growing longer roots that absorb stormwater and protect against erosion.

A new study released September 5 assesses the high economic value of riparian buffers in reducing flooding and erosion, cleansing the water, increasing property values, and more. (See also this earlier study. And here.)

The County, to its credit, does encourage trees. (p. 84)

Experts recommend a minimum width of ten feet of native plants and trees alongside an urban stream for effective erosion control and other benefits. Here’s some advice on restoring a bank on the bayou into a healthy, protective riparian area. Here are some Best Management Practices.

The Problems with Bank Hardening

FEMA encourages the use of green or natural approaches and soft structures rather than hard engineering solutions like retaining walls and riprap to protect against bank erosion.

Hardening the banks with metal, stone, or paving, compacting the soil on the banks with heavy equipment, stripping trees and native vegetation that absorb runoff as well as floodwaters, are all activities that increase and alter the flow in the stream and thus the risk of flooding and erosion. Streams and bayous, constantly eroding and rebuilding, naturally seek a dynamic equilibrium, a balance between flow and sediment, slope and speed, width and depth, and hard structures destabilize the balance, which can lead to unintended consequences. (See here and p. 29)

In addition, many local erosion control projects mistake vertical slumping and sloughing, the most common type of bank collapse on Buffalo Bayou, for lateral erosion caused by the flow of the stream, and property owners spend a lot of money on inappropriate (not to mention ugly) projects. Erosion and deposition of sediment, a constant process, are natural and necessary functions of a stream.

The federal flood insurance program recognizes the “the natural and beneficial functions of a community’s floodprone lands” and encourages “protection of natural floodplain functions” by providing lower premiums or greater discounts to communities that meet these goals.

How Are We Doing?

The current Harris County rating is 7 on a scale of 1 to 9, with 9 being the worst and 1 being the highest, offering the greatest discount (45 percent) on insurance premiums. The federal discount for flood insurance in Special Flood Hazard Areas (SFHA or 100-year floodplain) in Harris County is 15 percent. Outside of the 100-year floodplain the discount is 5 percent.

The current City of Houston rating is 5, somewhat better than Harris County. That rating offers a discount of 25 percent for policyholders in the 100-year floodplain and 10 percent outside of it.

Flooding Your Neighbor and Other People

Under Texas law, “no person may divert or impound the natural flow of surface waters in this state, or permit a diversion or impounding by him to continue, in a manner that damages the property of another by the overflow of the water diverted or impounded.”

The Harris County Flood Control District has guidelines, reviews plans submitted to city and county engineers, and consults with local floodplain administrators. But the district itself has no enforcement powers.

In the name of flood risk reduction, both the City and the County continue questionable and costly practices of “improving” our waterways through deepening, widening, stripping, straightening, mowing, and even hardening the channels. (Not to mention installing and replacing bigger and bigger drainage pipes.) These unsustainable practices, geared towards collecting and moving more water as fast as possible, are considered outdated, ineffective, unnecessarily expensive, environmentally damaging, and even counterproductive by leading flood experts. The modern approach is to slow and stop stormwater runoff before it floods the stream, to manage rain runoff in place, to widen the natural floodplain of the river to allow it to slow and absorb floodwaters. And to get out of the way.

“Preserving old stands of trees, natural swales, wetlands, oxbows, vegetated riparian areas, and meanders; building small weirs, sediment structures, wet gardens, and setback levees; lengthening streams, and accepting large woody debris in the channel are useful techniques. Using these practices to work with the natural motion of the river is more effective – and less expensive – in reducing flood damage and helping us realize benefits from the water.”  (p. 137)

“Improvement” of Bear Creek, once a natural stream, by the Harris County Flood Control District in order to increase the flow of rain runoff into Addicks Reservoir, a federal flood control dam in west Houston, one of two feeding into Buffalo Bayou. Addicks overflowed for the first time during Harvey, forcing the unprecedented opening of the floodgates during a storm. Photo by DM on Sept. 17, 2018

What Are Federal Waters?

Though the exact definition of federal waters is still being challenged in court, including by the State of Texas, the operating rule is that the Corps and thus the TCEQ regulates any activities (dredging and filling, for instance) taking place below the Ordinary High Water Mark (OHWM) of a navigable stream, including tributaries (even small creeks with bed and banks) and connected wetlands.

Though also subject to interpretation, the Corps defines the Ordinary High Water Mark as “the line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the banks, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.”

In addition, as mentioned above, under the Rivers and Harbors Act of 1899, the Corps regulates any “work or structures in, over or under navigable waters of the United States.”

Who Needs A Permit?  

Bank stabilization projects dumping fill for 750 linear feet or more along the bank of the bayou below the Ordinary High Water Mark (OHWM) require a permit from the Corps.

Plans to dump an average of one cubic yard of fill per linear foot for 1,000 linear feet or more below the OHWM require a permit from the Corps.

A pre-construction notice must be filed with the Corps for any project that involves a discharge into a special aquatic site (like a wetland) or is in excess of 500 feet in length, or that involves a discharge of greater than an average of one cubic yard per running foot below the OHWM.

The Texas Commission on Environmental Quality (TCEQ) is responsible for certifying that any permits issued by the Corps for discharging dredged or fill material into federal waters, including the bayou, complies with state law.

Some smaller projects – those that impact less than 1,500 linear feet of the stream, for instance – may still require a Corps permit but may not need a review by the TCEQ as long as they incorporate Best Management Practices – silt fences, for instance — for controlling erosion and sediment loss during construction until the bank has been stabilized.

Here is more information about federal and state permits.

Even the Flood Control District must have a permit from the Corps of Engineers to dredge and “improve” our waterways. The district has a General Permit to dredge and fill for “routine maintenance and repair.” It specifically prohibits deepening and widening channels,  channelization or the use of concrete except to replace existing concrete, or damaging special aquatic sites like wetlands. That permit expires on Dec. 31, 2019.

Any private citizen inside the city limits who wishes to conduct any “construction activity” in the floodway or floodplain must have a permit from the City of Houston Floodplain Management Office. According to the Jamila Johnson, director of that office, “to obtain a floodplain development permit, the applicant is required to provide a Certificate of Compliance indicating that the applicant has received all permits, licenses or approvals required by federal law, statute or regulation or required by any State of Texas statute, rule or regulation – this would include required approvals by the [Army Corps of Engineers].”

Here is how to look up whether a property owner has a floodplain permit from the City of Houston.

Outside of the city limits, Harris County also requires a permit to build “fences or fence-type walls” in the floodway or floodplain “provided it can be demonstrated the flow of the base flood will not be impaired and that base flood elevations will not be increased during the discharge of the base flood.” (p. 39)

Property owners who lose bank to erosion or a shifted channel may not legally rebuild that bank. The property line shifts with the shifting of the channel, says Riddell. “When the bank gets eroded the new gradient boundary will be on the new bank.  A riparian landowner can gain or lose land depending upon whether the bank gains or loses soil.” However, there are exceptions to this, including whether the bank shifts slowly or suddenly. The Army Corps of Engineers issues federal permits for “repair of uplands damaged by discrete events.” (p. 30) However, the permit “cannot be used to reclaim lands lost to normal erosion processes over an extended period.”

Is It Right? The Rights of Nature

Just because the authorities will give you a permit to do something doesn’t mean it’s a good thing to do.

In fact, the laws that are supposed to protect our environment, many of them dating from the 1970s, have been criticized for doing just the opposite: giving the power to government agencies to permit damage to the environment, destroy wetlands and streambanks, build in floodplains and floodways, cut down forests, etc.

A renewed movement, based on ancient law, recognizes that rivers and riverbanks, the air, all the water, the oceans and shores, our environment and climate, even wildlife, are a public trust, and that our government has an obligation to protect our natural assets as the common property of the people, for the benefit of all, including for future generations.

In other parts of the world, rivers in particular, and the waters and systems that nourish them, even trees, are recognized as living creatures, with the rights of personhood. For our own sake.

If corporations can have the rights of persons, rivers should too.

Respecting the process and power of nature, understanding how rivers and streams work, makes us all safer.

Buffalo Bayou immediately downstream of the extensive private erosion control project in the photographs above. Photo July 2018.

Filing a Complaint

What to do if you think someone might be dumping or building illegally on the bayou? Or in a way that is damaging?

Here is how to check whether a property owner has a permit from the City of Houston.

Here is how to complain to the City of Houston floodplain management office.

Here is how to complain to the permits office of the Harris County Engineering Department.

Here is how to complain to the Galveston District of the Corps of Engineers.

Here is how to complain to the Texas Commission on Environmental Quality.

In addition, you can report acts of pollution to air, water, or land, by calling the Houston Police Department’s Environmental Investigations Unit at 713-525-2728.

You can also report chemical spills, possible illegal use of pesticides, and other environmental violations to the Environmental Protection Agency.

Dumping of debris into ditches, streams, or bayous is a violation of the Houston Code of Ordinances Section 28-1. To report a violation or a maintenance problem, call the City’s Service Helpline by dialing 3-1-1.

Books on Buffalo Bayou

Along Forgotten River, Photographs of Buffalo Bayou and the Houston Ship Channel, 1997-2001
With Accounts of Early Travelers to Texas, 1767-1858, by Geoff Winningham

Buffalo Bayou: An Echo of Houston’s Wilderness Beginnings, by Louis Aulbach

Canoeing and Kayaking Houston Waterways, by Natalie H. Wiest

Pleasant Bend, by Dan Worrall

The Bayous of Houston, by James L. Sipes and Matthew K. Zeve

The Port of Houston: A History, by Marilyn McAdams Sibley

Books on Rivers and Flooding

Armand Bayou Illustrated – A Life on the Bayou, by Mark Kramer, Conservation Director and Chief Naturalist Emeritus at the Armand Bayou Nature Center in Pasadena, TX. A chronicle of a life lived working and playing on a beautifully preserved bayou, with emphasis on coastal prairie ecology, bayou ecology, wildlife, and native people. Photography by Gary Seloff.

Designing the Bayous: Control of Water in the Atchafalaya Basin, 1800-1995, by Martin Reuss

Floodplain Management: A New Approach for a New Era, by Bob Freitag, Susan Bolton, Frank Westerlund, and Julie Clark

Floodplains: Processes and Management for Ecosystem Services, by Jeffrey J. Opperman, Peter B. Moyle, Eric W. Larsen, Joan L. Florsheim, and Amber D. Manfree.

Goodbye to a River, by John Graves

In Praise of Floods, by James C. Scott

Life on the Mississippi, by Mark Twain

On the River with Lewis and Clark, by Verne Huser

Riparian Areas: Functions and Strategies for Management, Committee on Riparian Zone Functioning and Strategies for Management, Water Science and Technology Board, National Research Council

Rising Waters: The Causes and Consequences of Flooding in the United States, by Samuel Brody, Wesley Highfield, and Jung Eun Kang

Rising Tide: The Great Mississippi Flood of 1927 and How It Changed America, by John M. Barry

Sensitive Chaos, The Creation of Flowing Forms in Water and Air, by Theodore Schwenk

Stream Restoration, Neoliberalism and the Future of Environmental Science, by Rebecca Lave

Sweet & Salt: Water and the Dutch, by Maartje van den Heuvel and Tracy Metz

Texas Water Atlas, by Lawrence E. Estaville and Richard A. Earl, preface by Andrew Sansom

The Living Waters of Texas, edited by Ken Kramer, photographs by Charles Kruvand, foreword by Andrew Sansom

The Source: How Rivers Made America and America Remade Its Rivers, by Martin Doyle

The Water Will Come: Rising Seas, Sinking Cities, and the Remaking of the Civilized World, by Jeff Goodell

Tools in Fluvial Geomorphology, edited by G. Mathias Kondolf and H. Piégay

Unruly Waters: A Social and Environmental History of the Brazos River, by Kenna Lang Archer

Your Remarkable Riparian, A Field Guide to Riparian Plants in Texas and Your Remarkable Riparian Owner’s Manual, A Guide to Managing Riparian Areas

Books on Nature, Ecology, Geology, Environmental Law

Houston

A Prehistory of Houston and Southeast Texas: Landscape and Culture, by Dan M. Worrall

Energy Metropolis, An Environmental History of Houston and the Gulf Coast, by Martin Melosi and Joseph Pratt

More City Than Water, A Houston Flood Atlas, edited by Lacy M. Johnson and Cheryl Beckett

Power Moves: Transportation, Politics, and Development in Houston, by Kyle Shelton

Wild Houston, Explore the Amazing Nature in and around the Bayou City, by Suzanne Simpson and John Williams

Texas

A Guide to Freshwater Ecology, by Christine M. Kolbe

A Historical Atlas of Texas, by William C. Pool

Brandt Mannchen’s list of books about streams, rivers, wetlands, and forests

Common Texas Grasses, by Frank W. Gould and Stephan L. Hatch

Falling from Grace in Texas: A Literary Response to the Demise of Paradise, edited by Rick Bass and Paul Christensen. With essays by Rick Bass, Olive Hershey, Stephen Harrigan, Michael Berryhill, Laura Furman, and others.

Lessons from Leopold, Learning from the Land, by Steve Nelle

Native Texas plant books recommended by the Native Plant Society of Texas

Texas Mushrooms, A Field Guide, by Susan and Van Metzler

Texas Wildscapes: Gardening for Wildlife, Texas A&M Nature Guides Edition, by Kelly Conrad Bender

The Book of Texas Bays, by Jim Blackburn, photographs by Jim Olive

Trees of East Texas, by Robert A. Vines

General

A Sand County Almanac, by Aldo Leopold

American Canopy, by Eric Rutkow. Recommended by the late Terry Hershey

Braiding Sweetgrass, by Robin Wall Kimmerer

Nature’s Trust: Environmental Law for a New Ecological Age, by Mary Christina Wood

Noah’s Garden: Restoring the Ecology of Our Own Backyards, by Sara Bonnett Stein

Our Natural History: The Lessons of Lewis and Clark, by Daniel B. Botkin

Should Trees Have Standing? Law, Morality, and the Environment, by Christopher D. Stone

Silent Spring, by Rachel Carson

The Control of Nature, by John McPhee

The Field Guide to Geology, by David Lambert and the Diagram Group

The Hidden Life of Trees: What They Feel, How They Communicate – Discoveries from a Secret World, by Peter Wohlleben

The Natural History of Selborne, by Gilbert White

Urban Ecology: An Introduction, by Ian Douglas, Philip James

Walden, by Henry David Thoreau

Water: A Natural History, by Alice Outwater

Articles on Rivers, Flooding, and the Urban Environment

Houston, Texas, and Buffalo Bayou

“A Fatal Error: Erosion on Buffalo Bayou in the Memorial Park Demonstration Project Area,” Save Buffalo Bayou presentation July 25, 2017. An analysis of bank slumping on Buffalo Bayou and the consequences of mistaking vertical  bank collapse for lateral erosion. See also:

“$12 Million Bayou Project Based on A Mistake,” Save Buffalo Bayou, Aug. 17, 2017. The fundamental error of the Memorial Park Demonstration Project.

“After Hurricane Harvey, Don’t Empower the Engineers. Please,” Charles Marohn, Strong Towns, Sept. 8, 2017

“Best Way to Reduce Future Flood Impacts: Restore Our Floodplains,” John Jacob, Watershed Texas, Texas Coastal Watershed Program, Texas A&M University, March 5, 2018

“Birds of the Bayou,” photographs on Buffalo Bayou by Greg Lavaty, reported by Janice Walden, Nov. 11, 2018

“Can An Urban Stream Restore Itself?” by Susan Chadwick, adapted from a presentation to the Southwest Stream Restoration Conference in San Antonio, Texas, on June 2, 2016

“Cypress Creek Watershed: Analysis of Flooding and Storage Options,” report from the Greater Houston Flood Mitigation Consortium, May 2019. Undeveloped land should be preserved to prevent more overflow into Addicks Dam, which drains into Buffalo Bayou, and greater flooding downstream on Cypress Creek.

“Dammed If They Do, Dammed If They Don’t,” by Susan Chadwick, Save Buffalo Bayou, May 26, 2016, and in the Houston Chronicle, May 27, 2016. What happens when Barker and Addicks dams can’t hold all the rain?

“Detention, We Hardly Knew You,” an essay on Nature and the detention of raindrops and stormwater by Brandt Mannchen of the Houston Sierra Club, April 16, 2019

“Did Straightening Upper Buffalo Bayou Make Future Residents More Vulnerable to Flooding?”  by Susan Chadwick, Save Buffalo Bayou, Oct. 29, 2018. Federal project in late forties reduced bayou capacity upstream.

Drainage, Detention, and Development Regulations, dual reports from the Greater Houston Flood Mitigation Consortium, April 2019. Report 1: Current detention regulations are allowing new development to increase downstream flooding. Report 2: Development regulations should integrate green and gray infrastructure.

“Ecological Engineering in a New Town Development: Drainage Design in The Woodlands, Texas,” by Bo Yang, Utah State University, 2010

“Endless Repairs,” by Susan Chadwick, Houston Chronicle, Nov. 20, 2019. In 2010 the Harris County Flood Control District started bulldozing the banks of Buffalo Bayou for its “natural stable channel design” project in Buffalo Bayou Park. Tens of millions of dollars later, will the constant maintenance and repairs ever stop?

“Engineers Caused the 1935 Flood that Led to the Creation of the Flood Control District,” by Susan Chadwick, Save Buffalo Bayou, March 5, 2017

“Examination of Collapse Features Along the Channelized Sections of a Natural River: Examples from Buffalo Bayou, Houston, Texas,” by Thomas Helm, consultant geologist and canoe guide

“Flood Control’s Destructive Bayou Maintenance Will Lead to More Erosion, More Maintenance,” by Susan Chadwick, Save Buffalo Bayou, June 3, 2018. The importance of trees and large woody debris for streambanks and sediment control.

“The Flood Next Time: What We Can Do Now,” report of the Greater Houston Flood Mitigation Consortium, May 2019. Keep people high and dry. Remove people from harm’s way. Return people to normalcy.

“Freshwater Wetland Loss in the Houston Metropolitan Area: A Quantitative Estimate of the Loss between 1992 and 2010,” by John S. Jacob, Kirana Pandian, Ricardo Lopez, and Heather Biggs, Texas Agrilife A&M Extension Service, June 2015

Greater Houston Flood Mitigation Consortium, all research and studies from the collaborative research group following Harvey, 2017-2019.

“Houston’s Flood is a Design Problem,” by Ian Bogost, the Atlantic, Aug. 28, 2017

“How Harvey Hurt Houston, in Ten Maps,” by Propublica, the Texas Tribune, and Reveal, Jan. 3, 2018

“How the Coronavirus is like a Flood,” by Susan Chadwick, Save Buffalo Bayou, March 19,  2020

“Lessons from Hurricane Harvey,” by Daniel Grossman, Re.Think, March 15, 2018. A report from the American Geophysical Union annual conference in December 2017 in New Orleans, with numerous Houston-area academics offering their expert views on what can and should be done now about flooding.

“Managing Flooding in Place,” by Steven E. Eubanks, P.E., CFM Chief Stormwater Engineer, City of Fort Worth, and Brenda Gasperich, P.E., CFM Regional Engineering Manager, McKim & Creed.

“Pleistocene Meander-Belt Ridge Pattern near Houston, Texas,” by Dewitt C. Van Siclen, American Association of Petroleum Geologists (AAPG) Bulletin, Vol 69, No. 9, September 1985

“Power and Will: Eminent Domain for Preserving Land and Surviving Floods,” Save Buffalo Bayou, May 18, 2018. (See also “Eminent Domain and the Moral Hazard in a Golf Course,” by Susan Chadwick, Houston Chronicle, June 21, 2018)

“Preliminary Interpretation of the Stratigraphic and Structural History of Buffalo Bayou,” Houston Geological Society Bulletin, June 2024

“Quantifying Stormwater Runoff and Pollution Removal by Houston’s Urban Forest,” by Hannah Cruce, Water Resources Forester, Texas A&M Forest Service, presentation to the Urban Riparian Symposium, Houston, Texas, Feb. 15-17, 2017

Riparian Notes, by Steve Nelle

“Room for the River: What the River Scientist Had to Say,” Save Buffalo Bayou, Nov. 29, 2014

“Searching for the Original Meanders of Buffalo Bayou: Examination of Land Use and the Riparian Environment,” by Tom Helm, consultant geologist, presentation to the Urban Riparian Symposium, Feb. 16-17, 2017

“Slow the Flow: What Houston and Other Cities Are Doing to Reduce Flooding. And Make Life Better,” Save Buffalo Bayou, February 11, 2021. Includes numerous links and resources.

“Strategies for Flood Mitigation in Greater Houston, Edition 1,” report of the Greater Houston Flood Mitigation Consortium, April 10, 2018

“The Problem with Dams,” Save Buffalo Bayou, Nov. 9, 2017

“The Real Lesson of Hurricane Harvey,” Charles Marohn, Strong Towns, Sept. 5, 2017

“The Role of Riparian Vegetation,” Texas Riparian Association, 2012

“Who Owns the Bayou?” Save Buffalo Bayou, Sept. 20, 2018

“Widening and Deepening Our Bayous Is the Wrong Approach,” by Susan Chadwick, the Houston Chronicle Outlook, Jan. 23, 2017

General

“Atchafalaya,” by John McPhee (included in The Control of Nature)

“Bank Erosion as a Desirable Attribute of Rivers,” by Joan Florsheim, Jeffrey Mount, and Anne Chin, in Bioscience, Vol. 58, No. 6, pp. 519-529, June 2008

“Engineering with Nature: Alternative Techniques to Riprap Bank Stabilization,” Federal Emergency Management Agency

“Going with the Flow,” by Michael Kimmelman, the New York Times, Feb. 13, 2013

“How Fertilizers Harm the Earth More than Help Your Lawn,” Earth Talk, Scientific American (undated)

“How Trees Can Retain Stormwater Runoff,” by Dr. James R. Fazio, Tree City USA Bulletin No. 55, 2010

“Human Adjustment to Floods: A Geographical Approach to the Flood Problem in the United States,” by Gilbert Fowler White, PhD Dissertation, Dept. of Geography, University of Chicago, 1942

“In Praise of Dead Trees,” by George Wuerthner, Counterpunch, Dec. 24, 2018

“Making Room for Rivers: A Different Approach to Flood Control,” by Renee Cho, Earth Institute, Columbia University, June 7, 2011

“Natural Defenses in Action: Harnessing Nature to Protect Our Communities,” National Wildlife Federation

“Our Laws Make Slaves of Nature. It’s Not Just Humans Who Need Rights,” by Mari Margil, The Guardian, May 23, 2018. The growing recognition of legal rights for rivers, trees, and nature.

“Paving Paradise: The Peril of Impervious Surfaces,” by Lance Frazer, Environmental Health Perspectives, Vol. 113, No. 7, July 2005, pp. A456–A462

“Putting A Price On Riparian Corridors As Water Treatment Facilities,” by Ann L. Riley, San Francisco Bay Regional Water Quality Control Board, Aug. 6, 2009. (See also here.)

“River Systems and Causes of Flooding,” by Prof. Stephen A. Nelson, Tulane University, Oct. 17, 2016

“Setting Goals in River Restoration: When and Where Can the River Heal Itself?” by G. Mathias Kondolf. Stream Restoration in Dynamic Fluvial Systems: Scientific Approaches, Analyses, and Tools. Geophysical Monograph Series, Vol.194, pp 29-43

“Taming the Mighty Mississippi,” by Todd C. Frankel, Washington Post, March 14, 2018

“Taming the Mighty Mississippi May Have Caused Bigger Floods,” by Stephanie Pappas, Scientific American, April 10, 2018. More evidence for why “improving conveyance” doesn’t work: it causes more flooding.

“Ten Facts About Flooding,” American Rivers

“The Benefits of Large Woody Debris in Streams and Development of Management Alternatives,” by Jeffery M. Coffey and Tina Hendon, Tarrant Regional Water District, presentation to the Urban Riparian Symposium, Houston, Texas, Feb. 15-17, 2017

“The Growing Threat of Urban Flooding,”  from the University of Maryland, College Park and Texas A&M University, Galveston Campus, Center for Texas Beaches and Shores. 2018 “Many cities and towns across the United States are giving considerable attention to plans that support the capture of rain in areas where it falls.”

“Why Dredging Makes Flooding Worse,” by Charles Rangeley-Wilson, Dec. 9, 2015. See also “Is Dredging a Solution to Flooding Problems?” by Vicki Terwilliger, Republican & Herald, Pottsville, PA, August 19, 2018

What Happened in 2017? Some Things We Remember Besides Harvey

Permit Issued for Bad Project. Bad Project Is Killed

Also Boy Scouts, Bottles, That Big Horrible Flood, and Alligators

With photos!

Jan. 7, 2018

Updated Jan. 8 with more photos

The year 2017 started off for Save Buffalo with our editorial in the Houston Chronicle warning against the folly of believing that cutting down trees and widening and deepening our bayous and streams is the most effective response to flooding. Nobody does that any more. It’s counterproductive, damaging, and costly. The practical focus is on stopping stormwater before it floods a stream. But in Houston developer and engineering interests as well as politicians continue unwisely to call for bigger and more expensive drainage pipes and “improving” our bayous and waterways at great taxpayer and environmental expense. Widening the floodplain would be a good idea, creating Room for the River, as the Chronicle has reported as part of its excellent series in the wake of Harvey. Save Buffalo Bayou has been talking about Room for the River, working with nature, for years. That means not building in flood-prone areas and buyouts of buildings in the way, among other things.

Aerial photo of Buffalo Bayou flowing towards downtown by Jim Olive on April 7, 2017. The public forest of Memorial Park is on the bottom. Property of River Oaks Country Club is on the opposite bank.

Then in January Terry Hershey died, one of Houston’s inspirational environmental leaders, a protector of Buffalo Bayou.

In April Jim Olive went up in the air and took a stunning series of photographs, including the photo above, of Buffalo Bayou flowing past Memorial Park and the Hogg Bird Sanctuary in the middle of Houston. You can see the photos here. You might also want to look at our series, A Bend in the River, documenting the changes in a bend of the bayou through the seasons.

Later that month, after a delay of nearly two years following the last public comment period, the Army Corps of Engineers issued a permit for the long-delayed Harris County Flood Control District project to strip, dredge, and reroute over a mile of this stretch of the river, a historic nature area and one of the last forested, publicly-accessible stretches of the bayou. We asked and waited impatiently for the Environmental Assessment required by law.

While we waited an amazing trove of bottles and broken glass from the early twentieth century surfaced on the bank below the high cliff on the eastern edge of Memorial Park, an area designated a State Antiquities Landmark. This high bluff and the rest of this historic area would have been destroyed by the flood control district’s “restoration” project. You can thank Save Buffalo Bayou that it wasn’t.

Broken glass bottles, probably from the trash of the World War I military camp that was once in the area, washed out on the bank of Buffalo Bayou in Memorial Park. Photo May 19, 2017.

During that same month of May, Eagle Scout Paul Hung published an inspiring essay in the Houston Chronicle describing his Eagle Scout project benefiting Save Buffalo Bayou. Hung and a group of fellow scouts documented wildlife tracks on the bayou over a period of several months and created a pamphlet for the public to use to identify tracks. (Donate! We’ll send you the guide.)

Paul Hung and his fellow scouts from Troop 55 headed downstream on Buffalo Bayou to document wildlife tracks.

The Corps Releases the Environmental Impact Statement: It’s All Good! Not

And the Corps of Engineers finally released its Environmental Assessment. Which basically reported what the flood control district said, which was that it’s all good, no environmental impact from ripping out all the trees and vegetation, digging up the channel and banks, and shortening and rerouting the bayou. It’ll be better! More natural! It’s what the bayou wants!

So our super smart geologists went to work out in the field and documented the fact that Flood Control’s Memorial Park Demonstration Project was premised on a basic mistake, a faulty analysis.

Geologist Bill Heins, a member of Save Buffalo Bayou’s advisory board, at work in the field investigating slumping with his late beloved dog. This photograph was taken in the then-Memorial Park project area. Riffles in the water show the hard clay outcrop across entire stream bed, says Heins. River Oaks Country Club property on the right.

Basically, at the urging of the Bayou Preservation Association (BPA), Flood Control came up with a very expensive “solution” before conducting an analysis of the “problem.”  (The “solution” also happened to benefit members of the BPA board at the time.) The subsequent faulty analysis to back up this pre-selected solution was provided at taxpayer expense by a very compliant engineering consultant (who was represented on the board of the BPA by the manager for the project).

Slumping again of the south bank of Buffalo Bayou in Buffalo Bayou Park after Harvey. Photo Dec. 10, 2017, by SC

Slumping Is Vertical Collapse of  Stream Banks. It’s What Happens on Buffalo Bayou

What the analysis ignored is that what we have primarily on Buffalo Bayou and elsewhere is slumping of the banks. Our banks slide down vertically. The face rotates away. The Flood Control “restoration” plan said this wasn’t happening. But it is. (Property owners on the bayou, private and public, may have realized this, especially after Harvey.) There is really not much one can do about vertical bank collapse (slumping) except stay back and out of the way, stop landscaping, stop watering, control runoff, etc. Riprap (concrete rubble) is not going to fix it, and the weight may even cause more of a problem.

Slumping of the denuded bank of the River Oaks Country Club golf course where riprap was installed in 2015. Bank face slid down anyway. Photo 10.28.17

We took our findings and made our case to the elected county official in charge, a very smart man whose name starts with “Cactus” and ends in Cagle. He listened. (Also the project cost had doubled — from $6 million to $12 million at least, not including maintenance.)

The Memorial Park Demonstration Project is dead. Though no Flood Control project is truly ever dead, just shoved to the back of the shelf. See below.

And then came Harvey.

We had warned about the problem with the dams on Buffalo Bayou in the spring of 2016, after the April Tax Day floods. The Chronicle also published our report.

And now it had happened. In November of 2017 we published a new report, The Problem with Dams, describing how construction of dams can create a false sense of security and greater flood risk. In the coming year, we promise more analysis of plans for a new dam on Cypress Creek, the Third Reservoir.

In the meantime, distraught homeowners upstream on Buffalo Bayou below the dams were blaming trees (and the Corps of Engineers) for flooding their homes during Harvey, and politicians, engineers, and developer associations have turned up the volume on calls to remove the “kinks” and “bottlenecks” in the meandering, unchannelized bayou from Beltway 8 to Shepherd Drive, the beautiful stretch of the bayou that Terry Hershey and others fought to protect. Upstream of Beltway 8, the bayou had been stripped and straightened by the Corps in the 1940s. That straightened stretch immediately below the dams is now called Terry Hershey Park, and after Harvey, in a bid to do something quickly, the flood control district pulled off the shelf an old, controversial plan to raze trees in Terry Hershey Park and create basins for siphoning off flow from the bayou AFTER it was already in the stream. This made no scientific sense, but it cost less and it was a plan ready to go.

Save Buffalo Bayou spoke against that. And here in the Guardian also.

On a trip down Buffalo Bayou after Harvey, we found the gates to the public boat launch in Memorial Park at Woodway inexplicably closed. We discussed this with the Memorial Park Conservancy, and the gates were opened. On our paddle we saw newly revealed sandstone formations, an abundance of mussel shells in the newly deposited gravel and sand bars, a lot of sediment, lots of fallen trees, and a lot of slumping of the banks.  The small tributary stream flowing out of the Hogg Bird Sanctuary was blocked with sediment and debris.

A reader sent us photographs of alligator tracks. And we had more than 7,600 followers on our Facebook page.

All That Sediment

Where does all the sediment come from? Basically, it’s land that’s in transit towards the sea, and has been for eons (much faster when trees and vegetation have been removed from the banks and much more when the flow in the river is very high and strong). The sediment stops on one side of the river, washes out on another. During floods it lands on top of the banks, fertilizing the floodplain, all part of the natural process of the river and the reason why river valleys are so fertile. Possibly some of the abundant sediment is stuff that had previously dropped out of the water during prior storms when the water was held up  in the federal reservoirs while the floodgates were closed. Perhaps old sediment was washed out when the gates were opened during Harvey. Then too, there is a concept called “hungry water,” which is when sediment-poor water released from dams seeks out and picks up more sediment from the banks, causing more erosion, dropping larger loads when the flow slows at bends and obstructions. (See page 34.)

Sediment collected in the dog park pond in Buffalo Bayou Park. Photo Dec. 22, 2017

But the banks above Shepherd generally held up amazing well, those that haven’t been undermined by landscaping or bizarre “stabilization” projects. (Bank armoring can cause greater instability and erosion in nearby banks — see page 4 of this 2014 Public Notice about the Memorial Park Demonstration Project from the Galveston District of the US Army Corps of Engineers. See also this about riprap from the Federal Emergency Management Agency.) There has been a lot of slumping and apparent widening, and loss of trees and vegetation.  But the banks are naturally rebuilding, if we let them. What’s needed is woody debris against the banks, the trees and stuff that naturally falls in, collects and cleans sediment from the stream, reinforcing the banks against erosion. Nature has a system. It provides habitat for wildlife too. All part of the plan. Living rivers are healthier, cleaner, and more beneficial for us.

Since the fall, contractors hired by Harris County Flood Control have been working to remove large woody debris in Buffalo Bayou and elsewhere. To do this, they have used heavy equipment to dredge the channel and make it deeper so that they can float barges up and down the bayou, according to Flood Control. You might have witnessed this operation near San Felipe Road, for instance. We have urged them to leave as much woody debris against the banks as possible, while recognizing the need to clear the channel for stormwater conveyance. Our bayous and streams are our natural drainage systems, and Buffalo Bayou is our main river, with most other streams and creeks running into it.

Dredging and damming of Buffalo Bayou near Kirwick (north bank) and San Felipe by contractors hired by the flood control district to clear large woody debris from the stream. Photo Dec. 3, 2017

Hope for the Future

Unfortunately, dredging the channel is damaging to the ecosystem. There’s life in the bottom there. Also a lot of sandstone. But the flood control district was created in 1937 and given a limited number of tools to do what was current then: strip, dig, and straighten our streams. Times have changed. Our hope for the future is that our flood management practices will change also and evolve with the times.

And our thoughts are with those who lost so much during Harvey, who are still homeless, and who are still suffering.

Who Are They and What Are They Doing?

Dec. 29, 2017

(Update 2.19.18: The Committee has issued its Final Report. Read it here.)

(Update 1.23.18: The meeting of the Redevelopment and Drainage Task Force has been rescheduled for 3:30 p.m. Wednesday, Jan. 24,  at 601 Sawyer, First Floor Conference Room, Houston 77007.)

(Update 1.17.18: The meeting of the Redevelopment and Drainage Task Force scheduled for today, Jan. 17, has been cancelled due to weather. The meeting of the Houston-Galveston Area Council Regional Flood Management Council also scheduled for today also has been cancelled.)

(Update 1.2.18: Link to 2017 roster of the members of the Harris County Flood Control District Task Force has been fixed.)

The flood czar for the City of Houston now has someone to answer his phone. “This is Sallie,” she says. He also has a committee. This committee has met six times already.

Who is on this committee and what are they doing?

There are 48 members of the committee, including the flood czar himself, Steve Costello, whose technical title is chief resilience officer. The committee members were selected by Costello. Costello, a civil engineer, former city council member, and former mayoral candidate, was appointed to his position by Mayor Sylvester Turner after the Tax Day flood of 2016.

Most recently Costello was in the news when the Chronicle reported on Dec. 20 that his engineering firm, Costello Inc., engineered the development of residential subdivisions in the flood pools behind Barker and Addicks dams – even after finding, in a report commissioned by Harris County, that thousands of those homes were at risk of flooding from the reservoirs.

A representative of another engineering firm involved in the development of homes in the Barker reservoir flood pool is also on Costello’s task force. Lee Lennard is president and chief executive officer of that firm, Brown and Gay, now BGE.

The official name of Costello’s committee is the Redevelopment and Drainage Task Force. Its task, according to an email from Sallie Alcorn, who now answers the flood czar’s phone in his office at city hall, is:

“To ensure the City of Houston’s design standards are conducive to responsible development which does not negatively impact drainage, and

“To empower the City of Houston to effectively and consistently apply and enforce drainage-related development rules.”

Looking downstream at downtown Houston from the Shepherd footbridge over Buffalo Bayou. Photo on Aug. 28, 2017 by Jim Olive

But What They Are Really Talking About?

Task force discussions have focused on three topics: detention, fill, and drainage right-of-way, according to a member of the task force, which is weighted towards developers and real estate interests. (See below.) The results of these discussions are to be forwarded as recommendations to the City administration and to the city Legal Department.

Detention

Detention is the slowing down or temporary holding of rainwater running off the land into a drainage system, either natural or built. The faster the runoff, the higher the peak flow and greater the flooding. Removal of trees and vegetation greatly increases the speed of runoff. Covering the land with impervious surface increases runoff speed even more.

Currently the City of Houston requires new development to have .5 cubic feet of detention per square foot of new impervious surface, though there are exceptions. Points of discussion have been whether the detention requirement should be higher, as in 1 cubic foot per square foot of impervious surface, whether there should be any exceptions, and whether new detention should be required when redeveloping land that has previously been paved.

Fill

Fill is when dirt or some other material is brought onto a piece of property to elevate a structure. Elevating structures with fill is frowned upon as it causes runoff to drain onto neighboring properties.

According to Residents Against Flooding:

“Houston regulations on fill don’t take into account that: 1) detention should be added either on-site or nearby to compensate for the effects of fill dirt; 2) the water surface elevations for all the surrounding properties are elevated because water that used to be on the elevated property now runs off.  There is no requirement for mitigating fill except in a floodplain where it is required to be mitigated one-for-one; e.g., for every acre-foot elevation an acre-foot of detention must be added.  Unfortunately, even in a floodplain, fill can be mitigated by buying compensating detention from a mitigation bank, which may be located where it doesn’t really help like in a different watershed.”

Drainage Right of Way

The City would like to remove obstacles that have been placed in drainage ditches or other right-of-ways. That seems reasonable. It should be noted that there is a movement globally to “daylight” or open up urban streams. Rivers and creeks will continue to seek their historic paths, and sometimes will cause surprising flooding if filled or obstructed. Houston, which is not so flat as it seems, has covered up, filled, and even built streets, homes, and subdivisions on top of streams and ravines.

Note that open drainage ditches absorb as well as convey and cleanse stormwater more effectively than closed pipes. When filled with useful plants, they are also more scenic and beneficial. Frequently maligned as backwards or medieval, open drainage ditches run throughout many of Houston’s older neighborhoods. In others they have been replaced with closed pipes that are often too small and can serve as breeding grounds for mosquitos. (See discussion of ditches and pipes.)

The Members of the Task Force

The members of the committee are not secret, though Costello, who is very busy, didn’t respond to an initial request on Dec. 1 for the names of the members. Alcorn, after asking for another request in writing and checking with the City Legal Department, sent Save Buffalo Bayou the names of the task force members.

So of the 48 members of the task force:

• 13 are involved in real estate development or management
• 13 are engineers from the private sector generally working for developers and local government
• 12 are people who are or have been elected to public office or served in some neighborhood or community capacity
• 10 are engineers working for the public
• 9 have some drainage expertise
• 8 are lobbyists or publicists
• 4 work in the hospital or medical industry
• 4 are architects, landscape architects, or planners
• 4 are affiliated with the Urban Land Institute, a global real estate association founded in 1936
• 3 are connected to the West Houston Association, which promotes development in West Houston
• 3 contract for the government at some level, not including above-mentioned private engineers
• 1 works in the energy industry

Of those who have some discernible personal connection to a part of the city:

• 5 are from southwest Houston, including Sharpstown, Meyerland, and Westbury
• 2 are from west Houston
• 1 is from northwest Houston
• 2 are from north Houston
• 1 is from northeast Houston (Kingwood)
• 2 are from east Houston
• 2 are from southeast Houston
• 1 is from central Houston

 Next Meeting is January 17 at 3:30 p.m.

Though the meetings are not public meetings, they are open to the public. The task force will meet again on January 17, 2018, at 3:30 p.m. in the first-floor conference room at 601 Sawyer in Houston.

Here are the members of the Redevelopment and Drainage Task Force.

Other Governmental Flood Committees

Houston-Galveston Regional Flood Management Council

Also meeting on the same day and nearly the same time is the Regional Flood Management Council of the Houston Galveston Area Council. This group includes government representatives from the Houston region and surrounding counties.

The flood management council meeting is at 1:30 p.m. on Wednesday, Jan. 17, 2018, at H-GAC offices in Conference Rooms B and C located at 3555 Timmons Lane in Houston.

Harris County Flood Control District Task Force

The Harris County Flood Control District also has a citizens’ advisory task force that meets every three months on the fourth Monday of the month. The next meeting of that task force is January 22, 2018, at 2 p.m. at flood control district offices, 9900 Northwest Freeway. Here is the most recent roster of the members of this task force as well as the minutes of the last available meeting. Note that eight positions out of thirty-one are vacant.

Community Flood Groups

Among the citizen-led community flood groups are:

Cypress Creek Flood Control Coalition

Residents Against Flooding

Citizens Solutions to Houston Flooding

Local Initiatives

Houston Consortium

Bayou City Initiative

National Groups Addressing Flooding

American Rivers

National Wildlife Federation

Rain Ready

Slow the Flow

If You Build Them, They Will Come

Nov. 9, 2017

Some two months after the flood, neighborhoods on upper Buffalo Bayou were still haunted. A moldy, gray pall hung in the air like the Spanish moss draped in the trees. Houses were empty, their windows dark, walls stained where the dark floodwaters rose. Lawns and gardens were ruined, muddy and brown. Scattered piles of debris, broken mirrors and plasterboard, lined the nearly lifeless streets. The air, even out of doors, smelled of mildew.

“They’re having a hard time being more …. positive,” said resident Michelle Foss, her voice trailing off, looking towards a house where a family with children had to be rescued by helicopter from the roof.

Halloween decorations in front of a home in Briargrove Park on Buffalo Bayou that flooded during Hurricane Harvey. Photo by SC Oct. 20, 2017

Foss’s neighborhood is Briargrove Park. Like most of the subdivisions along Buffalo Bayou, it was developed in the decades after the federal government built two earthen dams west of Houston on what was then, in the late 1940s, mostly prairie—ranch and farmland. But the land next to the ancient meandering river, in the natural floodplain, was graced with forests of tall oaks and other trees—ideal for upscale residential development. With the construction of the dams, the floodplains were now considered safe. During heavy rains, the reservoirs behind the dams, Addicks and Barker, would hold back the waters of Buffalo Bayou, Houston’s main river, its Mother Bayou, and several creeks flowing into it, until the rain runoff collected in the bayou below the dams could empty into Galveston Bay.

It was a classic case of moral hazard, a situation identified by the late renowned geographer Gilbert White as early as 1942 in a paper titled, “Human Adjustment to Floods.” Government sponsorship of structural solutions like levees and dams that protect floodplains encourage development in those floodplains, which leads to damages that are often worse than what would have happened prior to construction of the levees and dams. (pp. 17-18) (See also p. 2.)

In the wake of Hurricane Harvey, the calls for a new or third reservoir in west Houston are virtually unanimous.  It’s worth considering whether that might be a mistake.

A False Sense of Security

A house that flooded next to Buffalo Bayou in Briargrove Park during Hurricane Harvey. Photo by SC on Oct. 20, 2017

For decades the scenic suburban neighborhoods in the bayou’s sloping floodplain forests remained safe and prosperous. More subdivisions, roads, schools, churches, and shopping centers were built, including upstream of the reservoirs, even literally in the reservoir flood pools. The two dams were designed originally with five outlets, four of them ungated, allowing for a combined discharge of 15,700 cubic feet per second (cfs) into the bayou, including the flow from rain runoff below the dams, as measured by the USGS gauge at Piney Point. Interestingly, this original planned rate of flow is about what would be released into the bayou during Harvey some 75 years later, when the US Army Corps of Engineers was forced for the first time to open the floodgates during a storm. The difficult decision—it was known that flooding would result—was made to protect the aging dams from being overwhelmed by an unprecedented amount of rain rapidly running off the developed land upstream. Three people died downstream and thousands of homes, businesses, and cars were flooded both below and above the reservoirs.

By the time construction of the dams was completed in 1948, however, two of those four uncontrolled outlets were gated, reducing by half the maximum free flow of the bayou and its tributaries through the dams to 7,900 cfs during a storm. Then, with more development along the bayou, the threat of flooding that development increased, and in 1963 the Corps decided to gate the remaining two outlets. Maximum flow was cut to 2,000 cfs, a quarter of the previous limit. (p. 12)

But after some sixty years of operation, the earthen dams had alarming seepage problems and voids. Adding to the pressure, development upstream of the dams had increased runoff into the reservoirs. Operations and maintenance costs, not including repairs, had tripled from about $900,00 in 1972 (p. 15-14) to about $3 million annually in today’s dollars (p. 36). In 2008 the Corps began $4.4 million in “interim risk reduction measures.” Concerned about the risk of catastrophic failure, in 2010 the Corps decided to reverse course and double the maximum release rate, including the downstream flow, to 4,000 cfs, in order to reduce pressure from high water levels in the pools behind the troubled dams. (p. 2) Flows any higher than that were now problematic. The Corps found that because of ever increasing development in the floodplain, flows at or above 4,100 cfs would flood the lower levels of homes built along the bayou from North Wilcrest to Chimney Rock Road, sixteen miles downstream. (p. 3)

In recent years, however, not even the dams could prevent homes from flooding along the bayou. Because of the rapid rate of rainwater runoff from our paved and built city, the flow in Buffalo Bayou can greatly exceed 4,100 cfs during a storm when the dam floodgates are closed. In 2015, during the Memorial Day flood, the flow exceeded 8,500 cfs, and again in 2016, flow was greater than 7,000. Residences up and down the bayou flooded during both events, including in Foss’s Briargrove Park neighborhood on the south bank, even with the floodgates closed.

And Then Came Harvey

The rain from Hurricane Harvey started Friday, Aug. 25, slowly at first. The dam floodgates were closed. Work on the new floodgates, a $72 million project finally begun in the spring of 2016, was suspended. By Sunday morning the flow in Buffalo Bayou was well over 10,000 cfs and houses near the bayou were flooding, though often first from the overflowing streets as drainage systems designed to empty into the bayou backed up and even reversed from the pressure of the swollen river.

Flooding in the street had trapped retired corporate attorney Landrum Wise in his house along with his wife and cats and a neighboring family with small children who had taken refuge on the second floor. The Wise house is one of the few two-story structures in Walnut Bend, a subdivision of ranch-style homes on the south bank of the bayou just west of Beltway 8 developed after construction of the dams. The backyard backs up to the woods of Terry Hershey Park, a 6.2-mile long stretch of the bayou immediately below the dams that was rerouted, stripped, and straightened by the Corps of Engineers in the late 1940s. The project cut off numerous meanders, many of them now remnant oxbow lakes. Channelizing, straightening, and concreting streams is now an outdated and largely abandoned practice. Flushing stormwater downstream as rapidly as possible, it was discovered, not only caused more flooding and erosion downstream but also disrupted the stream’s natural process, killing vital organisms and sending polluted water into our bays.

With the gating of the dams and restriction of the flow in the Sixties, funneling water downstream as fast as possible was thought to be less important. The stripped and straightened stretch, about 500 acres, was allowed to return to nature. The land was sold to the Harris County Flood Control District, which in the 1990s removed trees on the north bank and created a 100-acre-foot stormwater detention basin to hold overflow from the bayou during heavy rains. The area became a county park in 1993, named after the environmentalist, Terry Hershey, who in the mid-Sixties, together with other homeowners on the bayou, stopped the Corps from stripping, channelizing and concreting the entire length of the bayou from Beltway 8 to Shepherd Drive.

But the flood control district, as well as the City of Houston, continued with plans to remove more trees and build detention basins along the artificial channel in Hershey Park, despite the fact that trees and vegetation are powerful natural stormwater detention devices, critical for slowing runoff—increasing the lag time—and reducing peak flow in a flooding stream. Wise and many of his neighbors, including retired chemical engineer Michael Huffmaster, opposed the detention plans. The amount of detention to be created was “trivial,” said Huffmaster, standing recently behind his flooded house on a remnant oxbow of the bayou in the Lakeforest subdivision upstream from Wise and just downstream from North Wilcrest. “We need like 2,000-acre-feet,” he said. Their group, called Save Our Forest, advocated placing the detention basins on undeveloped private land and identified several alternative locations, said Huffmaster, who is also president of the Briar Forest Super Neighborhood, a group that includes many of the neighborhoods on the south side of the bayou near Terry Hershey Park as well as Foss’s neighborhood east of Beltway 8.

Michael Huffmaster, president of the Briar Forest Super Neighborhood, behind his flooded house on a remnant meander of Buffalo Bayou in the Lakeside Forest subdivision. Photo by SC Oct. 20, 2017

Alas, our state and local revenue system is built on sales and property taxes, and the need for property tax revenue in particular influences political decisions on everything related to development and flood management. Parks, green space, detention basins, buyouts remove land from the revenue stream; big dam and drainage projects spread public money around and theoretically protect flood-prone land for development. Building detention on public park land, which already produces no property tax revenue, is cheaper than having to buy private land which if developed would be a source of tax revenue.

At a standing-room-only meeting last month of the Briar Forest Super Neighborhood, the flood control district’s director of operations, Matt Zeve, was jeered by flooded property owners when he announced that the district would be reviving the detention basin plan, beginning with a vegetation survey, and terminating leases of flood control district property to homeowners on the edge of the park.

“What is that going to do for us?” angrily cried one flooded resident.

The Floodgates Open

Late on Sunday, Aug. 27, in the middle of the night and in the early hours of the next morning, the Corps of Engineers opened the floodgates on the reservoirs for the first time during a storm. Water was rising rapidly behind the 70-year-old earthen dams, and would likely soon flow around the spillways at the ends of the dams, also for the first time.

Buffalo Bayou was already flowing at over 10,000 cubic feet per second (Piney Point gauge), more than double the level for flooding property along the bayou. It was still raining and had been raining for three days. Hurricane Harvey had dropped some 10-17 inches of rain on the west side of town, though on the east side of Harris County the rainfall was nearly double. The rain wouldn’t stop until Aug. 29, two days later, ultimately deluging the region with more rain than had ever been recorded in the United States: nearly 65 inches on Nederland near Beaumont, with some 56 inches on southeast Houston, and 30-40 inches falling all over the county.

The floodgates on the dams were opened slowly at first. Huffmaster thought he was prepared. He researched the rainfall and how high the bayou would rise if the Corps released as much as 8,000 cfs from the two dams into the already flooded bayou. Downstream in Michelle Foss’s neighborhood of Briargrove Park, a resident made the same calculation. There the bayou would rise to about 71 feet. Street level was about 60 feet. (In fact, the neighborhood was even lower than people realized. The neighborhood had subsided about one foot since the late 1990s.) Massive flooding. An email warning went out to Foss, an energy economist, and her neighbors, many of them engineers, geologists, economists, accountants, and other professionals, “a data-driven group,” said Foss. Nobody believed the warning. “We thought, ‘This can’t be true.’” Only that one man who sent out the warning packed up and left.

Huffmaster and his wife ended up wading through chest-deep water to escape their flooding home, “our wonderful tree house.” Wise and everyone on his street were rescued by firefighters on rubber rafts, Jet Skis, and kayaks.

Harris County Flood Control District projection of flooding along Buffalo Bayou on Aug. 29, 2017, following release of stormwater from the federal dams.

Responses, Solutions, Priorities: Buyouts, A New Reservoir on The Prairie, Widening and Straightening.

As in many neighborhoods up and down the bayou and around the city, the talk on the street in Briargrove Park is of what to do, who is staying, who is rebuilding, who hopes to be bought out and leave, how the neighborhood will survive as a neighborhood.

Foss and her husband have lived in Briargrove Park since 1985. They are repairing their architect-designed home, built in 1960 and flooded for the first time during Harvey. Foss and some of her neighbors have also taken the initiative to research the topography and history of their neighborhood and come up with a plan to save it. After the flooding in 2015, residents had formed a Committee on Stormwater Drainage and Water Quality as part of their Homeowners Association. Longtime residents believe that a corner of the neighborhood had once had a swale or ravine that drained into the bayou. But the homeowners’ association had sold the land. The swale was filled and a house built on top. The house now floods, and the lack of drainage is causing other houses in the neighborhood to flood. The owner is ready to sell, and Foss’s committee is forming a nonprofit to raise money, both private and public, buy the house, restore the swale, and put the land into a trust or conservation easement as greenspace so that the streets can drain.

Michelle Foss in the backyard of a house built on a filled ravine in the Briargrove Park neighborhood on the south bank of Buffalo Bayou east of Beltway 8. Foss and her neighborhood committee are raising money to buy this house and restore the ravine for drainage and protection of other houses. Photo by SC Oct. 20, 2017

Foss calls it a “strategic buyout.” This home, valued at $750,000, and others in the neighborhood, are probably too expensive for the county to purchase as part of a government-funded buyout program. With politicians prioritizing big, expensive engineering projects, there isn’t enough money to go around anyway. But Foss has spoken with local political representatives and hopes her group can get some public support and possibly serve as a model. “I’m betting there are fifty neighborhoods with drainage like this,” she said.

For his part, Huffmaster is focused on taking the “kinks” out of the bayou. The “tortuous twists,” as he describes the bayou’s characteristic meanders, are stopping the flow, he says, causing the water to back up into the straightened stretch upstream and into his house. Theoretically, it should happen differently. The straightened stretch should send water shooting downstream and over the bank where it hits a meander. And in fact it does do that.

Downstream from Huffmaster and the straightened stretch of Hershey Park, the first big meander or “kink” east of the beltway flows around the cul-de-sac of Legend Lane on the north bank. The houses there flood badly. But Foss has a solution: another strategic buyout. She thinks the flood control district should buy and tear down the houses there. The bayou wants to cut straight across the point on which the houses are built. It should be allowed to do that naturally, said Foss.

“Messing around with the channel is only going to create more problems,” she said. “Figure out where river wants to go and take advantage of it.”

But Huffmaster is not alone in calling for “improvements” to the channel of Buffalo and other bayous and streams. Virtually every politician, engineering and developer group has listed enlarging channels or increasing conveyance in our waterways as a top priority, which is a lot like calling for bigger highways to deal with traffic congestion:  it doesn’t work.  Flooding begins on the land, and managing flooding in place, stopping raindrops where they fall, is the modern approach to reducing urban flooding.

In Buffalo Bayou in particular, “improving” the channel is also impractical and prohibitively expensive. At that recent Briar Forest Super Neighborhood meeting, Flood Control Operations Director Zeve explained why: most of the land is privately owned. And under current federal law, altering a stream like Buffalo Bayou requires replacing or “mitigating” the loss of ecological function by creating riparian wetland elsewhere.

The Third Reservoir: Who Benefits?

Also at the top of politicians’ flooding To Do list is The Third Reservoir. Virtually everyone is calling for a Third Reservoir, other than a handful of environmentalists and academics. It even has a price tag already: $400 million.

But what is this Third Reservoir? Where would it be? And what are its benefits?

“We have no details about the third reservoir,” says Mary Anne Piacentini, executive director of the Katy Prairie Conservancy. “So it’s hard to know exactly how to respond.”

“It’s fuzzy,” says Evelyn Merz of the Houston Sierra Club. “What exactly do they mean by a third reservoir? Is it a big hole in the ground, a traditional reservoir like Addicks and Barker? Or is the idea to have open space that can function as prairie and hold and retard runoff?”

The Third Reservoir appears to be a version of a plan developed by the Harris County Flood Control District known as Plan 5 (see p. 104), though Piacentini says the current idea is “most likely different.” Plan 5 is a variation of a levee in northwest Harris County that was proposed by the Corps of Engineers in 1940. The levee, as well as subsequent plans, was intended to capture the flooding from Cypress Creek that flows across the Katy Prairie into the Buffalo Bayou watershed and Addicks and Barker reservoirs. Development in the floodplain of Cypress Creek has exacerbated that flooding across the prairie, which is itself under heavy development pressure, particularly since the construction of the controversial Grand Parkway. (See also here and here and here.)

Generally, all parties agree that Addicks Reservoir in particular cannot handle more rain runoff. (Both reservoirs are for flood-control only, usually dry, and contain recreational facilities, even a zoo.) During Harvey, for the first time ever, storm water impounded behind Addicks, which is immediately north of Interstate 10, flowed over an emergency concrete spillway at the north end of its 11.7-mile long dam. Addicks can store about 130,000 acre-feet of water before the open-ended pool backs up and inundates subdivisions behind government-owned land to the north and west. Total capacity is about 200,000 acre-feet before the water begins flowing around the spillways, an elevation of 108 feet (above mean sea level). During Harvey, on August 30, the water level peaked at 109.1 feet, a record.

In a 2015 study, the flood control district estimated that during a so-called 100-year flood (pretty big rain, previously your maximum planned-for flood but lately a relatively piddling event), about 23,355 acre-feet of water flows from Cypress Creek across some 21,000 acres of largely undeveloped (mostly agricultural) prairie (p. 9) surrounding the Grand Parkway and into the streams feeding Addicks Reservoir (p. 179). (Harvey was way bigger than that – an unprecedented 1,000-year flood. The Memorial Day and Tax Day floods of 2015 and 2016 too were bigger, 500-year events though more localized.)

Apparently during the Tax Day 2016 rains, which landed heavily on northwest Harris County, it took about 24 to 30 hours for the Cypress Creek overflow to make its way into Addicks Reservoir once the storm had started, according to a 2016 analysis by HCFCD meteorologist Jeff Lindner. (p. 28)

The idea is to construct some sort of berm that would hold back this runoff even longer and protect for future development much if not most of those 21,000 acres served by the Grand Parkway  (p. 17), perhaps reserving some 5,000-6,000 acres as prairie. (p. 9) Development of the land, of course, could in turn cause greater, faster runoff that would have to be handled somehow. Another key question is how long the prairie behind the berm or dam would be submerged. Wetlands can hold water indefinitely, points out Piacentini, but prairie grasses cannot.

A good portion of the land behind the vaguely proposed berm is already under the protection of the Katy Prairie Conservancy, which is “legally, fiscally, and ethically” responsible for it, says Piacentini. For the past twenty-five years the Conservancy has been buying land and creating conservation easements in order to protect and restore native prairie grasslands and wetlands, one of the primary nonstructural or “green” defenses against flooding. The nonprofit organization now has more than 20,000 acres under protection, including 3,000 acres of wetlands as well as working ranchland, and hopes to more than double that. (The source of Buffalo Bayou is in the Katy Prairie.)

But as the Conservancy has been battling to preserve and restore prairie, developers and developer groups like the West Houston Association and Energy Corridor District have been busy developing it as fast as they can. Along with the Sierra Club, the Conservancy has been fighting off plans to put highways and development through the preserve and the prairie, with only partial success. (See Grand Parkway above.)

In the aftermath of the flooding from Harvey, Houston was roundly criticized for carelessly causing its own problems by paving over wetlands and prairie for profit. (See also this pre-Harvey editorial.)

An Alternative Solution

Restoring all 21,000 acres of the overflow area to prairie grass and wetland might be another way to handle the water. According to the Conservancy, one acre of wetland can store up to 4.6 acre-feet of water. An acre of tallgrass prairie will temporarily hold 1.2 acre-feet of water. So if one-third of that 21,000 undeveloped (agricultural) land were restored to wetlands, it could theoretically hold 32,000 acre-feet of overflow. And if the remaining 14,000 acres were restored to tallgrass prairie (storing temporarily 16,800 acre-feet of floodwater) the total storage capacity of the natural system would be 48,800 acre-feet, far more than the estimated overflow from Cypress Creek of 23,355 acre-feet during a 100-year event.

According to a 2014 public presentation by HCFCD, the Plan 5 version of the overflow plan would submerge some 11,300 acres of prairie to a depth of eight feet for seven days and produce 26,500 acre-feet of storage – opening some 18,000 acres adjacent to the Grand Parkway for potential development. (p. 43)

“We need to study the details,” says the Conservancy’s Piacentini. “We need to do an analysis of a nature-based project.

“We need to make sure people and structures are not placed in harm’s way.”

“As much as I love this house and this setting – It should never have been here.”

The fans were blowing hard inside Michael Huffmaster’s ruined dream home. The soaked first floor, which was built high above the 100-year floodplain, was stripped to the studs. The tall picture windows looked out to the remnant channel of the bayou behind sycamore trees and a dying magnolia. Here and there precious, rescued mementoes were carefully set out to dry: family photographs, a sand-dollar collection, a row of mildewed leather jackets.

“As much as I love this house and this setting – it should never have been here,” said Huffmaster sadly.

[Editorial note: Michelle Foss and Landrum Wise were donors to Save Buffalo Bayou in 2016.]