Tag Archive for: wetlands

Louisiana Loses Hundreds of Square Miles of Wetlands

A new study estimates that Louisiana lost approximately 750 square miles of wetlands between 1984 and 2020. Using a first-of-its kind model, researchers quantified those wetlands losses at nearly 21 square miles per year since the early 1980s. Even after accounting for gains in some areas due to sediment transported by rivers, the net loss was still 484 square miles.

Jet Propulsion Lab Study Points to Role of Coastal and River Engineering

A new study, titled “Leveraging the historical Landsat catalog for a remote sensing model of wetland accretion in coastal Louisiana” was  published in the Journal of Geophysical Research: Biogeosciences. Authors of the 2022 study include D. J. Jensen,  K. C. Cavanaugh,  D. R. Thompson, S. Fagherazzi, L. Cortese, and M. Simard. I quote liberally from their work below which is reproduced under a Creative Commons Open-Source license.

To compile the data, the authors used NASA/USGS Landsat satellite records to track shoreline changes across Louisiana.

Some of those wetlands were submerged by rising seas. Others were disrupted by oil and gas infrastructure and hurricanes. But…

The primary driver of losses was coastal and river engineering.

Such engineering can have positive or negative effects depending on how it is implemented, say the authors.

Opposing Forces at Work

Centimeter by centimeter, wetlands are built by slow accumulation called “accretion.” Rivers and streams carry both mineral sediment and organic materials. Accretion uses those materials to make new soil. It counters erosion, the sinking of land, and the rise of sea level.

According to the authors, human intervention and engineering often hold back or divert the flow of sediments that naturally accrete to build and replenish wetlands.

For instance, reinforced levees and thousands of miles of canals and excavated banks have isolated many wetlands.

The levees and canals have cut off the wetlands from the Mississippi River and the network of streams that course through its delta. In a few cases, engineering projects have added sediment to delta areas and built new land.

The researchers mapped land change in coastal Louisiana from 1984 to 2020. Basins that failed to build new soil, such as Terrebonne and Barataria, experienced the most land loss – more than 180 square miles (466 square kilometers). Credit: Jensen et al, Journal of Geophysical Research: Biogeosciences

By analyzing Landsat imagery with tools from cloud computing, the researchers developed a remote sensing model that focused on accretion or the lack of it.

Restoration Possible

Basins that failed to build new soil, such as Terrebonne and Barataria, experienced the most land loss over the study period—more than 180 square miles (466 square kilometers). Other areas gained ground, including 33.6 square miles (87 square kilometers) of new land in the Atchafalaya Basin and 43 square miles (112 square kilometers) in the area known as the “Bird’s Foot Delta” at the mouth of the Mississippi River.

“The Louisiana coastal system is highly engineered,” said Daniel Jensen, lead author and postdoctoral researcher at NASA’s Jet Propulsion Laboratory in Southern California. “But the fact that ground has been gained in some places indicates that, with enough restoration efforts to reintroduce fresh water supply and sediment, we could see some wetland recovery in the future.”

Economic Importance

Understanding wetland dieback and recovery is critically important because the Mississippi River Delta, like many of the world’s deltas, drives local and national economies through farming, fisheries, tourism, and shipping. “For the 350 million people who live and farm on deltas around the world, coastal wetlands provide a key link in the food chain,” said JPL’s Marc Simard, principal investigator of NASA’s Delta-X mission and co-author of the paper.

A map of soil accretion in coastal Louisiana showing higher buildup in parts of Atchafalaya and the “Bird’s Foot Delta,” where the Mississippi River system deposits mineral-rich sediment during flood periods. Credit: Jensen et al, Journal of Geophysical Research: Biogeosciences

Seventh Largest Delta on Earth

In several airborne and field campaigns since 2016, the Delta-X research team has been studying the Mississippi River Delta, the seventh largest on Earth. The team uses airborne sensing and field measurements of water, vegetation, and sediment changes in the face of rising sea level. The Landsat analysis builds on this airborne mission. Delta-X is part of NASA’s Earth Venture Suborbital (EVS) program, managed at NASA’s Langley Research Center in Hampton, Virginia.

Pioneering Technique

The new model by Jensen and colleagues is the first to directly estimate soil accretion rates in coastal wetlands using satellite data. Working with ground-based accretion records from Louisiana’s Coastwide Reference Monitoring System, the scientists were able to estimate amounts of mineral sediment from water pixels in the Landsat imagery and organic material from the land pixels.

The researchers said their approach could be applied beyond Louisiana because wetland loss and resiliency is a global phenomenon. From the Great Lakes to the Nile Delta, the Amazon to Siberia, wetlands are found on every continent except Antarctica. And they are declining in most places.

Wetlands are Most Vulnerable Ecosystems on Planet

The researchers called wetlands some of the “most vulnerable, most threatened, most valuable, and most diverse” ecosystems on the planet.

But they also said a new generation of spaceborne tools, such as synthetic aperture radar, can increasingly inform conservation policies on the ground. This is because satellites support near-continuous mapping of ecosystems at a scale and consistency that is nearly impossible through traditional surveys and field work.

50% Less Carbon Being Buried

The futures of our wetlands and coastal communities are intertwined with climate change, so sustainable management is critical. They store decomposing plant matter in soil and roots. Thus, wetlands act as “blue carbon” sinks. They prevent some greenhouse gases (carbon dioxide and methane) from escaping into the atmosphere.

But when vegetation dies, drowns, and fails to grow back, wetlands can no longer bury carbon in soil.

At current rates of wetland loss in coastal Louisiana, carbon burial may have decreased 50% from 2013 estimates.

“Forty percent of the human population lives within a hundred kilometers of a coast,” Simard said. “It’s critical that we understand the processes that protect those lands and the livelihood of the people living there.”

Posted by Bob Rehak on 11/11/22 based on a summary article by NASA in Phys.Org and the original.

1900 Days since Hurricane Harvey

Wetlands Once Covered Area Where 138 Nesting Birds Were Slaughtered, Maimed

Last weekend, a contractor killed or maimed 138 nesting egrets and herons in the Cypress Towne Lake Area while clearing land. Little surprise the birds were nesting there. That area was once pockmarked with wetlands that are rapidly being developed.

Wetlands provide free stormwater retention. They also provide valuable habitat that supports a remarkable level of biodiversity. In terms of the number and variety of species supported, wetlands rival rainforests and coral reefs. Trouble is, they also provide cheap land for developers. That brings people into direct conflict with wildlife.

Great Egret preening on nest while waiting for eggs to hatch. File photo not taken in Cypress. Copyright © Bob Rehak 2022.

Nesting waterfowl make a pretty good biologic indicator of wetlands.

Property Rights vs. Right to Life and Right to Information

By law, it’s illegal to disturb migratory birds such as herons and egrets while they are nesting. But the contractors in question did not respect that law even though they could have waited a month or two.

Don’t get me wrong. I’m all for property rights. And I support responsible development. But that means finding balance. Balance sustains life. It also provides beauty that supports property values. Would you rather raise your kids in biological barrens? Or in close to nature in a place teeming with life?

Finally I believe in the right to information that helps people make informed decisions and markets self-regulate. For instance, if people fully knew the flood risk on a piece of property before buying it, that knowledge could reduce demand, perhaps moderate prices, and discourage future development of wetlands.

But sadly, flood potential is often the last thing buyers look at. At closing, they’re probably provided with a survey that shows they’re above the base-flood elevation (aka the 100-year or 1%-annual-chance floodplain). Then it’s “Where do I sign?” And, “When can I move in?”

That the home might have been built on wetlands is the farthest thing from their minds…until the foundation settles, the walls crack, and doors and windows start to stick.

Where to Learn about Property Built on Wetlands

But a little investigation with free apps or on public websites, might help buyers drive harder bargains that would pay for the foundation leveling they will probably need eventually.

From U.S. Fish and Wildlife Service National Wetlands Mapper. This shows the wetlands that used to exist in the area where the birds were killed and maimed.
1944 Aerial Photo of same area from Google Earth Pro. Cherrywood Bend Drive is where contractors were clearing land when they encountered the nesting egrets and herons.

Cypress Towne Lakes is a miracle of engineering that created livable space out of areas that once were wetlands. But the developer’s website shows only impressive homes and amenities, including a chain of lakes. It mentions none of the area’s natural history.

“You Can’t Outsmart Nature”

A wise banker once told me, “You can’t outsmart nature. Nature always wins. We need to give Mother Nature her room.” Perhaps that’s why his bank has almost a billion dollars in assets.

Posted by Bob Rehak on 5/19/22

1724 Days since Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

How Soon We Forget!

How soon we forget. Hurricane Harvey was just 4.5 years ago. Since then I have documented dozens, if not hundreds of questionable practices that erode margins of flood safety.

It Didn’t Have to Be That Bad

Harvey was the largest rainfall event in the history of North America. However, with better regulations and construction practices, it didn’t have to be as destructive as it was.

  • Lax regulations;
  • Willful blindness;
  • Development and construction practices that pushed the safety envelope;
  • Relentless destruction of forests and wetlands near rivers and streams;
  • And homebuyers who didn’t realize their true flood risk…

…made Harvey’s destruction worse than it otherwise would have been.

No one factor by itself would explain Harvey’s destruction. But put them all together, and it’s like “death of a thousand cuts.”

The sheer volume of material – more than 1,000,000 words on this site – makes it difficult for people to see the big picture sometimes. To put 1,000,000 words into perspective, the average novel contains only about 100,000. So I’m condensing the website into a book that includes the themes below.

No One Wins Arguments with Mother Nature

During an interview with Milan Saunders and his daughter Lori, Milan said, “No one wins arguments with Mother Nature.” How profound! It doesn’t matter how many surveys, studies and engineer stamps you have on your home’s title. If you don’t:

  • Respect the rivers.
  • Give them room to roam.
  • Protect wetlands.
  • Allow plenty of margin for safety…

…you will flood.

Thought courtesy of Milan Saunders, Chairman/CEO of Plains State Bank. That’s his daughter Lori’s house during Harvey.

Understanding the Causes of Flooding

Excess sedimentation is one of them. Sediment pollution is the single most common source of pollution in U.S. waters. Approximately 30% is caused by natural erosion, and the remaining 70% is caused by human activity.

Large islands built up during Harvey blocked both drainage ditches and rivers. Below, you can see a large sand island (top) built up at the confluence of the Kingwood Diversion Ditch where it reaches the San Jacinto West Fork at River Grove Park. This sand bar reached 10-12 feet in height above the waterline and helped back water up into Trailwood, the Barrington and Kingwood Lakes and Kings Forest. Before the Army Corps dredged this island, River Grove flooded five times in six months. It hasn’t flooded since.

The Kingwood Diversion Ditch and West Fork San Jacinto were almost totally blocked by sediment dams deposited during Harvey.

The second photo above was taken a few hundred yards downstream on the West Fork from the first. It shows “Sand Island” – so nicknamed by the Army Corps. It took the Corps months to dredge this island which they say had blocked the West Fork by 90%.

A certain amount of this sedimentation can be explained by natural erosion. But mankind also contributed to the sheer volume by other practices which I will discuss below.

Respect the Rivers

The red polygons in the satellite image below surround 20-square miles of sand mines on the West Fork of the San Jacinto in a 20 mile reach of river between I-45 and I-69. That exposes a mile-wide swath of sediment to erosion during floods and increases the potential for erosion by 33x compared the river’s normal width.

Even without floods, mines sometimes flush their waste into the rivers. The shot below on the top right shows the day the West Fork turned white. The TCEQ found the source of the pollution upstream: a sand mine that had flushed 56 million gallons of sludge into the West Fork (bottom right).

Influence of sand mines of West Fork San Jacinto water quality.

End the War on Wetlands

Wetlands are nature’s detention ponds. During storms, they hold water back so it won’t flood people downstream. But we seem to want to eradicate wetlands. The images below show the Colony Ridge development in Liberty County. Wetlands (right) are being cleared (left) to make way for the world’s largest trailer park. The acceleration of runoff wiped out FM1010 during Harvey. The road still has not been repaired.

Colony Ridge in Liberty County.

Conservation Costs Much Less than Mitigation

Halls Bayou at I-69 near Fiesta. Image on left shows whole subdivisions that that to be bought out before detention ponds on right could be built.

All across Harris County, especially in older areas inside Beltway 8, apartment complexes, homes and businesses are built right next to bayous and channels. This makes it difficult to enlarge streams or build detention ponds when necessary. One study showed that preservation of floodplains is 5X more cost effective than mitigation after homes flood. Yet private developers keep crowding bayous and residents keep demanding public solutions.

Respecting Individuals’ Property Rights While Protecting Others’

In Texas, it sometimes feels that an individual’s right to do what he/she wants with property trumps others’ rights NOT to flood. You may think you’re protected by all those public servants reviewing and approving plans. But what happens when developers and contractors decide to ignore the approved plans? Here’s a prime example: the Laurel Springs RV Resort near Lakewood Cove.

The approved plans said that “Stormwater runoff shall not cross property lines.” So what did the contractors do? They pumped their stormwater over the development’s detention pond wall. When that took too long, they dug a trench through the wall. Then they laid pipes through the wall to permanently empty the sludge into the wetlands of Harris County’s new Edgewater Park.

This apparently violated the developer’s City of Houston permit, the Texas Water Code, TCEQ’s construction permit and the developer’s stormwater pollution prevention plan. Four investigations are currently swirling around this development. The contractor also cut down approximately 50 feet of trees in Edgewater Park along the entire boundary line and received a cease-and-desist letter from the Harris County Attorney. But the damage is done.

Balance Upstream and Downstream Interests

About 10% of all the water coming down the West Fork at the peak of Harvey came from Crystal Creek in Montgomery County. But the wetlands near the headwaters of Crystal Creek are currently under development. And the developer is avoiding building detention ponds with a “beat-the-peak” survey. This loophole allowed by Montgomery County says that if you get your stormwater to the river faster than the peak of a flood arrives, then you’re not adding to the peak of a flood and you don’t have to build detention ponds. So developers conduct timing surveys to reduce costs and maximize salable land.

What happens when upstream areas develop without consideration for the impact on downstream property owners.

Of course, speeding up the flow of water in a flood is the opposite of what you want to do. To reduce flooding, you should hold back as much water as possible.

The slide above shows part of a new development called Madera at SH242 and FM1314 being built on wetlands near Crystal Creek.

The graph on the right shows what happened on Brays Bayou without suitable detention upstream. Floodwaters peak higher, sooner. Harris County has spent more than $700 million in the last 20 years to remediate flooding problems along Brays.

How much will we need to spend when more areas like Madera get built upstream on the West Fork?

How Quickly We Forget!

FEMA’s Base-Flood-Elevation Viewer shows that in that same area, developers have already built homes that could go under 1-5 feet of water in a 100-year flood. These homes are actually in a ten-year flood zone. And yet more homes are being built nearby. On even more marginal land!

In recent years, the price of land as a percent of a new home’s cost has risen from a historical average of 25% to approximately 40% today. This puts pressure on developers to seek out cheaper land in floodplains, reduce costs by avoiding detention pond requirements, pave over wetlands, and reduce lot sizes resulting in more impervious cover. All contribute to flooding.

Of course, smart homebuyers would not make such risky investments. But few lack the expertise to gauge flood risk. Educating such homebuyers will be one of the major objectives of the book I hope to write.

Posted by Bob Rehak on 2/23/2022

1639 Days since Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

Dirt Excavated from Woodridge Being Used to Build Up Laurel Springs RV Resort

Sprint Sand & Clay, the company hired by Harris County Flood Control to excavate 500,000 cubic yards of dirt from Woodridge Village, began hauling some of it to the controversial Laurel Springs RV Resort near Lakewood Cove this morning.

Wake-Up Calls

My phone started blowing up before breakfast with dozens of complaints about Sprint truck traffic. So, I began investigating. I first went to the Woodridge Village site. Drone photos and on-the-ground observations revealed that Sprint was indeed hauling dirt from the Woodridge Village excavation site.

SW corner of Woodridge Village taken Wednesday 2.9.22. Sprint trucks line up to haul off dirt.

I followed one of the trucks all the way to Laurel Springs Lane where I observed it dumping its load. Along the way and at each end, I saw many more Sprint trucks – up to four at a time. There was a veritable parade of dump trucks making round trips along Woodland Hills Drive, Kingwood Drive, Chestnut Ridge, and Laurel Springs Lane.

Orange truck from above enters RV site several minutes later and turns toward detention pond.
The orange truck dumps its load just north of the pond near an area marked as the 500-year floodplain. Other equipment spreads it out.

Will Storm Drains Be Adequate?

Sprint trucks had also dumped dirt near a new “north entrance” to the site.

In the shot above, note the ponding water from 0.2 inches of rain more than a week ago. The contractor’s Stormwater Pollution Prevention Plan describes this soil as “silty sand” to a depth of 18 inches (Page 18).

They may want to recheck that before installing more storm drains.

Other Issues Noted Today

Most trucks that I observed used what has now become the “south” entrance. The fresh load of bullrock laid down days ago has already been covered with mud. That accounts for all the dirt tracked into the street.
While the storm sewers were still unprotected from dirt, at least a street sweeper was onsite today.
Another unprotected storm sewer and contractor taking water from City fire hydrant. Photo courtesy of Robin Seydewitz.
All the dump trucks I observed were this large size, not the kind that holds 10 cubic yards.

Good News/Bad News

The start of serious excavation at Woodridge Village comes as welcome news to the people of Elm Grove and North Kingwood Forest who flooded twice in 2019. However, it’s equally worrisome to the people of Forest Cove and Lakewood Cove. Many expressed concerns about potential flooding.

Risks from Building Up Land

Should existing residents be concerned about that? Yes, was the answer I got from one respected hydrologist who spoke on condition of anonymity. He likened the built-up area to a berm and said that “You don’t want a berm to stop overland sheet flow.”

The elevation survey shown below comes from the RV park’s Stormwater Pollution Prevention Plan. It shows that the land naturally slopes from northeast to southwest. Building up the RV property would definitely prevent water from the NE from flowing in that direction. Sheet flow would divert south along Laurel Springs and put an evacuation route at risk.

Survey shown in developer’s Stormwater Pollution Prevention Plan shows elevation going from 83.1 in the NE to 61.4 in the SW, a difference of more than 20 feet.

East to west along the southern boundary, the elevation drops from 67 feet at Laurel Springs to 61 feet near the railroad tracks.

Another risk is that sheet flow with nowhere else to go could back up Lakewood Cove storm sewers at the same time that the RV park is trying to pump water into them to compensate for its undersized detention pond.

Texas Water Code

Chapter 11.086 of the Texas Water Code covers situations like these.

If someone sustains water damage on their property due to a neighbor’s property, questions as to who may be liable may arise. Surface water runoff — most often caused by excess rainwater — is the common culprit. Texas law holds landowners responsible for damage to neighboring property due to diversion of surface water.

If you find the legal wording in the water code difficult to understand, visit this Texas State Law Library page for resources written in plainer English.

SWPPP Plan Good for Laugh-Out-Loud Moment

I received a copy of the RV Park’s SWPPP plan today from the TCEQ. Parts of it made me laugh out loud. For instance, the section about “Receiving Waters, Wetlands and Special Aquatic Sites” said:

“No existing wetlands or other special aquatic sites have been identified at or near this site [Emphasis added].”

Page 18 of Laurel Springs RV Park SWPPP prepared by Construction Eco Services

Obviously, they didn’t glance across the southern property line or consult the National Wetlands Database. I can’t wait to read the rest of this plan to uncover more gems.

From US Fish & Wildlife Service National Wetlands Inventory Mapper. The RV Park is going in just above the large green area labelled PF01A Future Edgewater Park.

Posted by Bob Rehak on 2/9/22

1625 Days since Hurricane Harvey

New MoCo Development Being Built on Wetlands in 10-Year Flood Zone

At least part of Madera, a new 1,700-acre development in Montgomery County that straddles FM1314 immediately north of SH242, is being built on wetlands and is in a 10-year flood zone.

US Fish & Wildlife Map Shows Wetlands Dot Development

Magera Wetlands
From US Fish & Wildlife Service National Wetlands Inventory. Madera will stretch past the left/right edges of this picture north of SH242 (the east/west highway near bottom.) FM1314 bisects picture from N to S in middle.

FEMA’s Base Flood Elevation Viewer Shows Flood Risk

From FEMA’s Base Flood Elevation Viewer. Extent of 100-year flood zone shown on left. 10-year flood zone shown on right.

Note that this survey shows only about a quarter of Madera (see below). The survey stops abruptly on the western margin. So, it is hard to say with certainty how bad flooding is throughout the rest of the site.

Yellow outline shows approximate outline of FEMA BFE survey shown above within Madera tract (black/white outline).

Option to See Depth of 100-Year Flood Waters

Also note that the purple area shows only the extent of 100- and 10-year floods. However, within the FEMA BFE viewer, you also have the option to select a layer that illustrates the depth of 100-year floodwaters. See below. (FEMA does not offer the option to show the depth of 10-year floods.)

FEMA BFE viewer
FEMA’s estimated Base Flood Elevation Viewer showing extent of 100-year flood on left and depth on right.

Limitations of BFE Viewer

Of course, FEMA shows “estimated conditions” before developers bring in fill and alter drainage. But notice how a pre-existing development near Madera would fare in the same 100-year flood. You can see the close up below just above SH242 near the right edge of the image above.

FEMA shows that most homes in this development are still in the flood zone and would still flood to a depth of 1-2 feet in a hundred-year flood.

The street leading out of the development to SH242 could be under more than FIVE FEET of water in places!

FEMA Base flood Elevation Viewer

FEMA’s “Estimated Base Flood Elevation” is “The estimated elevation of flood water during the 1% annual chance storm event.” Structures below the estimated water surface elevation may experience flooding.” A 1%-annual-chance flood is also known as a 100-year flood. FEMA defines properties with a 1% annual chance of flooding as having “high flood risk” and says they have a 26% chance of flooding during the life of a 30-year mortgage.

Purposes of BFE Viewer

The agency developed its Base Flood Elevation viewer with several purposes in mind. To:

  • Inform personal risk decisions related to the purchase of flood insurance and coverage levels.
  • Inform local and individual building and construction approaches.
  • Prepare local risk assessments, Hazard Mitigation Plans, Land Use Plans, etc.
  • Provide information for “Letter of Map Amendment” (LOMA) submittals.

A LOMA lets the developer of a subdivision change the depiction of how flooding affects his/her subdivision. It’s the key to offering up-to-date risk assessments.

Full BFE Reports Available

FEMA also lets you download or print full BFE reports that give more specific estimates of flood depth at exact points, not just within a wide area.

FEMA’s BFE Viewer also gives you the option to print out a detailed flood-risk report by clicking on a point.

At the point shown above, you could expect 4.2 feet of water above the land surface in a 1%-chance flood. For the full report, click here.

Here’s what that point looked like last Saturday (1/22/22) from the air.

Madera will eliminate wetlands but claims it will have no adverse impact.
Madera development today at FM1314 and SH242, the point shown in BFE report above.

Cross-check this area on the maps above for wetlands and swamps! Then you can see why it’s so soupy.

BFE, Fill Not Mentioned in Drainage Analysis or Construction Plans

Text searches of Madera’s construction and drainage plans showed no references to “BFE” or “base flood.”

It seems unlikely that a “cut and fill” operation could excavate enough dirt from Madera’s drainage channel (dotted blue line with red parallel lines) and detention ponds to raise the whole site out the hundred-year flood zone. Five feet is a lot of fill for a 1700 acre site.

To raise a site this large, contractors would likely have to bring in fill from outside the property. But a text search from the word “fill” did not turn up any exact matches either.

So maybe they’re just planning to create the world’s biggest drain and hope to carry water off before it can reach homes.

However, a summary of the Madera master drainage plan notes…

“Coordination with MCED [Montgomery County Engineering Department] and adjacent property owners is recommended … on the potential need for inundation easements.”

Revised Channel Alignment Memo, 2/19/21, Page 11

Still, engineers for the development claim it will have “No adverse impact.”

To review Montgomery County regulations regarding flood zones and drainage, see the documents under the “Construction Regs in Flood Hazard Areas” tab on my reports page. You’ll see plenty of opportunities for improvement.

Posted by Bob Rehak on 1/27/22

1612 Days since Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

How to Find and Verify Flood-Related Information: Part II

This is Part II in a series about how to find and verify flood-related information. Yesterday’s post focused on finding good information about flood vulnerabilities. This second part will focus on reviewing developers’ plans. The second can compound the first.

The very first sentence of the Texas Water Code § 11.086 begins with a warning not to flood your neighbors. It says, “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 second sentence declares that a person injured by diverted water may sue to recover damages. Of course, at that point the damage has already been done. Lawsuits are expensive and take years. And the defendant, usually a developer, will always point to plans prepared by a professional engineer and approved by a government body. Suing them will require expert witnesses. And the defendant will likely claim that you wouldn’t have flooded except for an Act of God.

Lawsuits are tall, expensive mountains to climb. So concerned residents near new developments are better off closely scrutinizing plans before they’re built and closely monitoring construction to ensure developers follow the plans.

You can’t stop development. But you can ensure developers play by the rules.

But how do you find and verify their plans?

Need to Find and Verify Info

If you notice a large piece of property for sale near you, monitor it closely. Check with the listing agent. Also check Houston’s Plat Tracker website. It’s updated before every meeting of the Planning Commission and shows items on their agenda. Houston also maintains a map-based website that shows projects in various stages of approval throughout the City and its extra-territorial jurisdiction.

Leap into action if you find a potential cause for concern near you. The next step is to obtain the development’s plans, the drainage impact analysis and soil tests. The developer must prove “no adverse impact” to people and properties downstream.

How you obtain those plans and studies depends on the development’s location. If inside a municipality, check with your city council representative. If you live outside a municipality, your best starting point will probably be your county engineer or precinct commissioner.

The plans are public information and must be provided in response to Freedom of Information Act (FOIA) Requests.

Signed, Stamped, Approved and So Obviously Wrong

In every case I reviewed during the last four years where someone flooded because of a new development, something jumped out of the plans that should have raised concerns for reviewers, but didn’t.

For instance, after Colony Ridge engineers apparently mischaracterized soil types, Plum Grove flooded repeatedly. The engineer said soils would let more water soak in than actually could. That meant the developer didn’t have to build as many detention ponds and could sell more lots. But it also contributed to flooding homes downstream.

Another example, the engineers for Woodridge Village claimed there were no floodplains on the property when there were. The property just hadn’t been surveyed yet.

In those cases, multiple other issues surfaced after close review. Wetlands that had been ignored. Substandard construction of detention ditches that led to severe erosion. Failure to implement stormwater quality controls. Failure to follow plans. Ignoring Atlas-14 requirements that led to undersizing detention ponds by 40%. And more.

In another development, I spotted safety issues related to river migration that had been ignored. Underground parking next to the floodway of the San Jacinto River. Failure to consider flood evacuation.

Concerned citizens must learn how to obtain and review such plans for potential problems or hire a consulting engineer.

Here are some things I’ve learned to look for.

Soil Tests

Are they accurate? Were the samples taken at representative points? Or did they conveniently ignore wetlands? Permeability of the soils will affect the amount of detention needed. The level of the water table could affect the amount of detention provided.

  • Highly permeable soils like sand have a high rate of infiltration and will let developers get away with less detention. Clay-based soils will require more. One engineer told me, “Soils like Colony Ridge reported don’t exist in the State of Texas.”
  • If plans call for a ten-foot deep detention pond, but the soil test encounters a shallower water table, that will compromise the pond’s capacity. Capacity should be calculated from the top of standing water, not the bottom of the pond. If the pond is already half full, that half shouldn’t count.

You can check the soils that a developer reports against the USDA national soil database.

Floodplain Issues

Floodplain maps in Harris County are currently being revised. That may not be the case in surrounding counties. The lack of updated flood maps endangers current residents, by letting developers build to old and ineffective standards.

Developers often try to beat the implementation of new requirements. This happened in the case of Woodridge Village. It’s also happening in the case of the Laurel Springs RV Park and Northpark South along Sorters-McClellan Road. The entrance to the Northpark development sits in a bowl. A quick check of the elevation profile on the USGS National Map confirmed that. During Harvey, local residents tell me that not even high-water rescue vehicles could get through that intersection. Put the Cajun Navy on standby now.

Wetland Issues

Filling wetlands requires an Army Corps permit for some, but not all wetlands. Whether they fall under the Corps’ jurisdiction depends on how far up in the branching structure of a watershed they are. Those near the main stem are jurisdictional. Three levels up may not be.

The US Fish and Wildlife service has thoroughly documented wetlands in this area. Check their National Wetlands Database and appeal to the Corps if you find a problem. At a minimum, the developer may be forced to buy mitigation credits somewhere nearby, which could help reduce flooding.

Drainage Issues

Is a new development’s detention pond capacity adequate? Is it based on the right percentage of impermeable cover? If the pond(s) fill up, where will the water go?

Calculating detention capacity requires math skills most people don’t have. But you can check the basis for the calculations. Are plans based on new Atlas-14 requirements? Are plans meeting current Houston and Harris County requirements?

Current City of Houston and Harris County Requirements for Detention Pond Capacity

In the case of the RV park, the developer will provide roughly half the current capacity requirement thanks to a grandfather clause in the regs. You can find construction guidelines for Houston, Harris County, MoCo and Liberty County on the Reports Page under the Construction tab.

Also see where they’re routing excess water in case of an overflow.

In the case of the Laurel Springs RV Park, the developer said they would route the water to a detention pond near Hamblen and Laurel Springs in anything greater than a two year rain. See below.

Screen Capture from Laurel Springs RV Resort Drainage Impact Report shows that in anything greater than a 2-year rain, overflow water will could threaten homes in Lakewood Cove.
RV Park Site Outlined in White. Overflow described above would presumably follow red path.
Laurel Springs RV Park as of 11/29/21. Detention pond will go in foreground, but overflow will go into pond at top of frame according to text above.

Missing Details from Drainage Impact Analysis

I have requested additional details three times from the City but still have not received them. I suspect they may not exist. All other plan requests have been filled.

So what happens when the Lakewood Cove detention pond fills up? Or gets covered up in a flood? Overflow from the RV park will contribute to flooding someone downstream.

The developer also said excess capacity would get to the Lakewood Cove pond by overland sheet flow. That could threaten homes on the southwest corner of Lakewood Cove – visible in the middle of shot above.

But a City engineer reviewing the plans said overflow would follow the railroad tracks on the western side of the RV park. Hmmmm. Two engineers – one who developed the plans and another who approved them – 180 degrees apart. What’s a concerned citizen to do?

If the engineers who develop and review such plans were always right, no one would ever flood. But we do. So always find and verify those plans.

To see the first part of this series, click here.

Posted by Bob Rehak on 11/29/2021

1553 Days since Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

Are We Winning or Losing the Battle to Reduce Flooding?

Valley Ranch, the new downtown of East Montgomery County, seems to be exploding with growth. The northwest quadrant of I-69 and the Grand Parkway developed first. Now the focus is shifting to the southwest quadrant where more than 500 acres are being cleared near the banks of White Oak Creek. People downstream from I-69 to Caney Creek have experienced flooding recently. This raises the questions, “Will the flood mitigation measures being put in place at Valley Ranch be enough?” and “In general, are we winning or losing the battle to reduce flooding?”

The Relentless Forces of Development vs. Battle to Reduce Flooding

Last week, I posted about the new Amazon distribution center, shown above at A. Today, I’d like to focus on four areas west of Amazon, shown as 1-4. All sizes below are approximate. I used the measuring tool in Google Earth.

  • 1 = 170 acres
  • 2 = 120 acres
  • 3 = 100 acres
  • 4 = 135 acres

I took all the aerial photos below on 11/6/21.

This interactive map of Valley Ranch shows what’s planned where.

Area 1: Marketplace

Most of Area 1 just south of the Grand Parkway will be future retail space dubbed “Marketplace.”

Area 1 looking SW from over the Grand Parkway will contain retail. However, apartments are now going up in the far top left corner. What’s that soupy area in the middle? See below.
US Fish and Wildlife Service (USFWS) Wetlands Mapper shows a wetland area that corresponds to the soupy area in photo above this one.
Here it is again. Looking north toward the future Marketplace and the Grand Parkway.
Closer shot of apartment construction.

Area 2: Commercial District

Looking East from over Grand Parkway toward I-69. Commercial area is the clearing in the distance. White Oak Creek is the wooded area that runs diagonally through the frame.
Closer shot of commercial area. From over White Oak Creek looking N toward Grand Parkway. I-69 on right.

Areas 3 and 4: Medical District

Medical District looking SW from over I-69.

You can tell by the amount of standing water on this property that drainage could be an issue. Note below how the standing water coincides with the former wetlands mapped by USFWS below.

Areas 3 and 4 shown in US Fish & Wildlife Service Wetlands Mapper.

Sediment control during clearing becomes a real issue for sites like this. Note the series of trenches channeling standing water toward the storm drain on the I-69 feeder road below.

Looking W from over I-69 across southern portion of Medical District. Note attempts to drain the site through the storm sewer in the foreground.

That basket of rocks is supposed to filter out sediment before it reaches the drain. But when I enlarged the image, look what I found.

Someone trenched around it!

Reverse angle of same area
looking E toward I-69 shows two large detention ponds under construction on left.

We Need Regional Flood-Mitigation Scorecard

The pace of development seems to be faster than the pace of flood mitigation.

Four and a quarter years after Harvey, we’re halfway done with dredging the sediment flushed downstream to the headwaters of Lake Houston. We have yet to build one regional detention basin upstream. And according to the Houston Chronicle, the proposed new gates for Lake Houston’s dam are being scaled back to fit the available budget.

And all of that is on the asset side of the ledger.

On the debit side, thousands of acres are being cleared with little to no detention capacity, faster than I can photograph and catalog them.

Somebody smarter than I needs to develop a formula that shows whether society is winning or losing the battle to reduce flooding. Are new developments springing up faster than we can mitigate the runoff from them?

Certainly, responsible developers exist who retain their rain. This may be one. That remains yet to be seen. But other developers exist who do not retain their rain. The question is, “Are there more irresponsible developers than the responsible kind?

Posted by Bob Rehak on 11/9/2021

1533 days since Hurricane Harvey

New Caney ISD’s West Fork High School Blocked Out; Access Being Enhanced

Although much finish work remains, contractors have finished blocking out New Caney ISD’s new West Fork High School. Walls, structural steel and roofs are up. Some windows are in. Now they are widening Sorters-McClellan Road. They are also building another access route through woods that will connect to Kingwood Place Drive, the street immediately west of the HCA Kingwood Medical Center.

Photos Taken 11/6/2021

I took all of the shots below on November 6, 2021, with the exception of the last one from November a year ago.

New Caney ISD West Fork High School Construction as of 11/6/2021. Looking NE from over Sorters-McClellan Road toward HCA Kingwood Medical Center and Insperity in top center.
Looking south from over Sorters-McClellan Road, which is apparently being widened in front of the high school and then some. Note the wetlands and cypress trees in the upper right.
Looking north from over detention pond at south end of campus. I-69 in upper right.
Fieldhouse, track and football field.
New access road through woods will connect with Kingwood Place Drive
Looking south. Note windows being installed in center.
Looking SE. Much sitework remains.
From a higher altitude, you can see the proximity to the San Jacinto West Fork. From the upper left, it curves around the large pond then becomes visible again to the left of the sand mine in the upper right.

Wetlands Gone Forever

From US Fish and Wildlife Service Wetlands Mapper. Green areas are/were freshwater forested/shrub wetlands. Blue/gray areas are freshwater ponds. High school site is in center of frame. Image taken shortly after clearing. Note large area of former wetlands where athletic fields will be.

I’m sorry to see the wetlands go, but now that they’re gone, I want to see them complete the drainage for this campus ASAP to make sure everything gets channeled into the detention pond. That will minimize the chance of flooding neighbors.

Progress in One Year

New Caney ISD has posted an update on construction that indicates the percentage of completion for each of the project components as of October 29.

It was just a year ago, that this site was virtually nothing but dirt. Contractors had just started pouring concrete for the first parking pad.

From Nov. 13, 2020.

New Caney ISD expects to finish construction by the summer of 2022.

General plan for New Caney High School #3

Posted by Bob Rehak on November 8, 2021

1532 Days since Hurricane Harvey

More West Fork Wetlands near Northpark Drive Could Soon Be Developed

Take Northpark Drive all the way west to where it ends at Sorters-McClellan and you will run into a 279-acre tract that the Houston Planning Commission will consider at its November 18th meeting. Sand mining has already destroyed most of the 279 acres. Now a developer wants to fill in the wetlands and build homes on the rest.

This is like “death by a thousand cuts.” Or the the Parable of the Rivet Poppers.

Parable of Rivet Poppers

Imagine you’re getting on an airplane and you see someone popping rivets out of the wing. You ask the pilot, “What’s that guy doing!?”

The pilot says, “Oh, he’s popping rivets. Our accountants have found that can eliminate weight and improve fuel economy.”

“But won’t that increase risk?” you ask.

The pilot replies, “Somewhat, but our engineers believe it won’t bring the plane down.”

Would you get on that airplane? Would you live in this proposed development? Or downstream from it? See details below.

Details of Northpark South

Here are the plans presented to the Planning Commission last Thursday for a plat of Northpark South. The commission deferred action on them until the next meeting. The developer is Hannover Estates, LTD. RG Miller engineered the development.

Pretty location! Just don’t let your kids go fishing there.
Of course, the homes will be built on the highest ground. But look how far the floodplain (dotted line) cuts into them.
Northpark South floodplain
Northpark South floodplains. Of course, these are based on 1980s data. Don’t be fooled by the data on the map. That’s the date of the background image. In Harris County, the new flood maps will reportedly expand the floodplains by 50% as a rule of thumb. But this is MoCo and the last update was much longer ago.
Here’s how that area looked during Harvey.
US Fish & Wildlife Service Map of wetlands (and former wetlands) on the site (center of frame).
Looking W from over end of Northpark Drive. Sorters-McClellan cuts through bottom of frame from left to right. West Fork cuts through sand mines in the background.
The barren spot just right of center is the wetland area that will be filled in to make home sites.
Meet the neighbors.
Where the subdivision drainage will go…straight into the West Fork.
Water flowed so quickly through this area during Harvey that it moved and sunk this excavator within the mine.

Another Development Targeted at the Uninitiated?

The shame of it is that if Northpark South gets built, the developer will likely build starter homes and market them to couples with young children. They’re the least knowledgeable about flood risk.

Of course, the people downstream won’t get to make a decision about this. But you can testify about it at the next Planning Commission meeting on November 18. Here are details.

Pop. There goes another rivet.

Posted by Bob Rehak on 10/31/2021 with thanks to Paul Ehrlich for the parable and Mai Truong for the heads up on this

1524 Days since Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

Colony Ridge Expanding North Into More Wetlands

After months of expanding Colony Ridge to the east, the developer is now pushing north. The new area is outlined in red below.

From Google Earth Pro. Red box shows new expansion area to the north of those currently being developed.

US Fish and Wildlife Shows Area Contains Many Wetlands

According to the US Fish and Wildlife Service, the new area contains numerous wetlands. So did the partially developed area below it.

Here’s the same general area highlighted within the USGS National Wetlands Inventory.

Wetlands are nature’s way of slowing water down after a rain. They also filter runoff before it reaches streams, reducing the amount of sediment pollution.

The photos below, all taken on 5/26/2021, show the same kinds of business practices that just earned Colony Ridge eight complaints from the Texas Commission on Environmental Quality during nine investigations.

Looking north from a helicopter. Notice how ditch and roads are beginning to push into woods at top of frame.
As with previous sections recently developed, Colony Ridge is not too picky about piling dirt next to ditches where sediment can wash back in.
Piling dirt next to the ditches seems to be a standard practice. Note how it’s already washing back into the ditch in the lower left of this photo.

If the developer were following best management practices, according to the TCEQ and Stormwater Pollution Protection Plan recommendations, you would expect to see temporary grass, rock gabions, silt fences, and hay bales in these photos. All check the flow of sediment into ditches.

Draining the swamp
Looking SE toward the east part of Sante Fe (Sections 6-11) already cleared. Note swampy areas at bottom left.

Biden Trying to Restore Clean Water Act Protections

Ironically, all this development comes as the EPA under the Biden administration seeks to put teeth back into the Clean Water Act. The administration is trying to restore the definition of “Waters of the United States” that Trump restricted. Yesterday, the Justice Department submitted a legal filing that begins that process.

The EPA and Department of the Army have formally requested repeal of the Trump-era rule. That rule exempted many developments near upstream tributaries such as Luce and Tarkington Bayous from the need to obtain permits under the Clean Water Act. It basically removed large swaths of land from regulation by the US Army Corps of Engineers.

According to this Associated Press article by Matthew Daly on 6/9/2021, environmental groups and public health advocates said Trump’s interpretation of Waters of the US “allowed businesses to dump pollutants into unprotected waterways and fill in some wetlands, threatening public water supplies downstream and harming wildlife and habitat.”

Daly quotes Jaime Pinkham, acting assistant Army secretary for civil works as saying, “The Trump-era rule resulted in a 25% reduction in the number of streams and wetlands that are afforded federal protection.”

It’s unclear at this time whether rollback of Trump regulations will affect Colony Ridge. Even if the changes survive legal and legislative challenges, it could be years before they take affect.

By then, the world’s largest trailer park will have doubled again in size.

Posted by Bob Rehak on 6/10/2021

1381 Days since Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.