Tag Archive for: Erosion control

TCEQ Again Cites Colony Ridge for Lack of Pollution Controls

This morning, the Texas Commission on Environmental Quality (TCEQ), notified me that they again cited the controversial Colony Ridge development in Liberty County for lack of pollution controls.

In early June, TCEQ reprimanded Colony Ridge after eight separate investigations into its construction practices. Last October, TCEQ said Colony Ridge construction practices had a “reasonable likelihood of endangering human health.” This new investigation showed the developer and its contractor, D. Burton Construction LLC, had still not implemented best management practices as required by regulations and the company’s own stormwater pollution prevention plan. To see aerial photos of that I took of the area under investigation in late May, click here.

Area of investigation. The dotted triangle in the lower left is the northeastern tip of Harris County.

For the full 185-page TCEQ report, click here. For a summary of the contents and findings, read below.

Summary of Findings: Investigation #1736609

On June 15, 2021, the investigator found active construction along Long Branch Creek. He noted that the slopes of the creek were not stabilized. He also found un-stabilized sediment piles along the banks of the creek, a damaged silt fence, and an unstabilized drainage channel. Additionally, the slopes of Long Branch Creek were also un-stabilized.

Continuing north into Section 12, the investigator noted more un-stabilized sediment piles on the edges of un-stabilized drainage ditches connected to Long Branch Creek. The slopes of Long Branch Creek were also un-stabilized in Section 12. While documenting active land clearing, the investigator noted an unprotected tributary that flows into Tarkington Bayou.

After reviewing the site’s stormwater pollution prevention plan, the investigator determined that Section 12 did not have erosion control measures installed as prescribed.

TCEQ Investigation #1736609

The investigation confirmed lack of best management practices at the construction site. One alleged violation was issued: Failure to install minimum controls.

From Attachment 4, “Unstabilized slopes in Long Branch Creek. Unstabilized sediment piles on the banks of Long Branch Creek.”
More unstabilized slopes and unstabi­lized sediment piles leading to Long Branch Creek from Attachment 4.

As per the Construction General Permit (CGP), D. Burton Construction LLC was required to “design install and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants” and to document compliance with the stormwater pollution prevention plan (SWPPP).

That part of the document takes up the first four pages.

Supporting Documentation

A series of attachments make up the the next 181 pages.

  • Attachment 1: Vicinity Map
  • Attachment 2: TCEQExit Interview sent on June 24, 2021
  • Attachment 3: Permit Information
  • Attachment 4: Investigation Photographs
  • Attachment 5: Photo Locations Map
  • Attachment 6: Flyover Photographs
  • Attachment 7: Records Request Sent on June 16, 2021
  • Attachment 8: Response to Records Request

Purpose of SWPPP and Control Measures

The primary purpose of erosion control is to protect surface waters. To do that, TCEQ says contractors should protect slopes and channels.

“Convey concentrated storm water runoff around the top of slopes and stabilize slopes as soon as possible. This can be accomplished using pipe slope drains or earthen berms or other flow controls that will convey runoff around the exposed slope.”

“Avoid disturbing natural channels and the vegetation along natural channels, if possible.”


The SWPPP also contains a lengthy discussion of erosion and sediment controls beginning on page 78. I recommend it for anyone who thinks he/she may be receiving eroded sediment from a construction site.

Soil Report Largely Consistent with Earlier Findings Showing Need for Detention Ponds

Starting on page 128, you can also read an extensive custom soil report from the USDA Natural Resource Conservation Service.

It shows extensive wetlands in the area under development and low-permeability soils, consistent with the soils I reported on December 20 of last year. The soils are also consistent with all the ponding shown on the map above.

They suggest this area will have a high amount of runoff after development. Little water will sink into the soils. And that could increase downstream flooding, unless the developer installs sufficient detention pond capacity.

Colony Ridge is in Liberty County. But if Harris County guidelines applied, they call for .55 acre feet of detention capacity per acre (for developments greater than 640 acres). Thus, if the area under development is 1200 acres, that would call for 660 acre feet of detention ponds (or 100 acres – six and a half feet deep). I saw nothing that large during my last flyover at the end of May.

Downstream Impacts

The rivers of mud previously documented coming out of Colony Ridge have impacted Tarkington Bayou, Luce Bayou, Rocky Branch, Long Branch, and the East Fork San Jacinto. Eroded sediment from this area is likely contributing to the giant mouth bar now setting up on the East Fork. That will cost the City of Houston tens of millions of dollars to dredge.

It’s not clear at this time whether the developer has improved his erosion-control measures. Two calls to the TCEQ have not yet been returned.

Posted by Bob Rehak on 9/3/2021 based on TCEQ Investigation #1736609

1466 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.

Rivers of Mud: Largest Development in Liberty County Openly Flaunts Drainage Regulations

To prevent erosion that sends sediment downstream, current Liberty County Drainage Regulations specify that developers must:

  1. Plant grass on the banks of ditches
  2. Construct backslope interceptor swales

But aerial photos taken this week show that drainage ditches in the massive Colony Ridge development rarely have grass on their banks. And while criss-crossing the development in a helicopter on Monday, December 7, 2020, I did not see one backslope interceptor swale. This, DESPITE Colony Ridge being the largest development in Liberty County. Or maybe it’s BECAUSE Colony Ridge is the largest development in the county. Perhaps they think they can flaunt regulations.

Colony Ridge is even larger than any of the cities in Liberty County – by far. You would think that would make violations more visible. But apparently, it makes them less so. Much to the detriment of downstream communities.

What Ditches Should Look Like If Regulations Were Followed

Regs in Liberty County are similar to those in Harris County. Here’s a photo of a drainage ditch in Harris. It shows both grass and interceptor swales in use and how they help prevent erosion. Note the swales behind the shoulders of the ditch. Also notice the concrete structures that help pipe rainwater from the swales to the bottom of the ditch. They prevent water from washing down the ditch slopes and causing erosion. Had the developer followed the regs, which represent best practices, his ditches should look like the one below.

Backslope interceptor swales with drain pipes leading to bottom of ditch help prevent erosion. Photographed in Humble in Harris County.

Erosion Control as Practiced in Colony Ridge/Liberty County

Now, compare that to the following 18 photos. I took all of them over Colony Ridge on Monday. Some show newly developing areas subject to the latest regulations adopted in 2019. Others show areas already developed under regulations from 2004. The older regs required grass, but no interceptor swales. The newer regs require both. No attempt has been made to bring the older ditches up to newer standards despite obvious erosion problems.

Note how the developer has a habit of piling dirt next to the ditches. The TCEQ cited the developer for that practice earlier this year because dirt could wash back into ditches during rains. However, the developer obviously doesn’t fear the TCEQ. He’s still doing it. On a grand scale.

Ditch on right has grass on banks but no backslope interceptor swales. Note dirt piled on banks and how it’s already eroding into ditch.
No grass. No swales. Piles of dirt on the ditch’s shoulders.
Again. No grass. No swales. More dirt on shoulders.
Some weeds, but no grass. No swales. And a river of mud.
Another river of mud.
Rio de Lodo. “Lodo” translates to mud, sludge or mire in English.
This ditch has more corrugations than a cardboard factory thanks to the total absence of erosion-control measures.
Ditch in new area without erosion control measures near Highway 99 extension (in upper left of frame). Note eroded sediment already moving down the ditch. See close-up detail below. Regulations say that grass should be planted on ditch shoulders immediately after ditch construction.
Detail from upper right of previous photo.
Note erosion in ditch in foreground and other ditch T-ing into it.
Pipe from resident’s home enters ditch at top, accelerating erosion. Enlargement shows brownish liquid dripping from pipe.
Even newer stick-built homes on left don’t get erosion protection.
Note a wheelbarrow next to the man. Perhaps he’s trying to excavate blockages in the ditch behind his house.
Note how erosion has taken dirt from under fences. Better keep the dog on a leash!
The mud in ditches has made them playgrounds for ATVs, further contributing to erosion.
The mother of all eroding ditches in Colony Ridge. (BTW, note the absence of fire hydrants on the long street left of ditch.)
Baby ditch with another river of mud.
Erosion has created a training ground for mountain goats in Colony Ridge.

Externalizing Development Costs

All this erosion (from approximately 12-13,000 acres) eventually winds up in the East Fork of the San Jacinto and Lake Houston. There, taxpayers must pay to have it dredged and filtered out of the water supply.

Downstream from Colony Ridge. East Fork Mouth Bar after Imelda. After depth in this reach is now 3 feet. It was 18 feet before Harvey.
New Northeast Water Purification Plant at Lake Houston will cost taxpayers $1.4 billion.

The East Fork Mouth bar forms a sediment dam that also has contributed to the flooding of more than a thousand homes.

Meanwhile, the developers cheaping it out are counting their change all the way to the bank.

Posted by Bob Rehak on 12/10/2020

1199 Days since Hurricane Harvey and 448 since Imelda

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.

Perry Homes’ Contractors Return to Woodridge Village, But Undo Some Previous Work, Add to Sediment-Laden Runoff

After pulling all construction equipment from the Woodridge Village site in December, Perry Homes’ contractors returned this week. They are still working on the S2 (second southern) detention pond. But the new work appears to undo some previous work, and make sediment-laden runoff worse.

Woodridge Still Far Short of Promised Detention Capacity

After about 15 months of working on the Woodridge Village site, Perry Homes still has only 23% of the detention capacity installed. And even that does not yet meet Montgomery County regulations (see below). None of the work this week focused on new detention ponds that would reduce flood risk for Elm Grove residents.

Perry Homes had promised to build three ponds on the northern section. But they have not started any of those yet.

And Far Behind Schedule

On October 17th last year, an attorney for Perry Homes, J. Carey Gray, promised the Houston City attorney that Perry would have S2 completed in no more than 45 days. It has now been 86 days since Mr. Gray sent his letter and the work is still far from complete. I’m sure this creates an embarrassment to the Mayor of Houston, especially considering that Perry Homes gave $5000 to his re-election campaign. It creates the appearance of trying to buy favors.

Still Does Not Comply With MoCo Regulations

I previously detailed seven Montgomery County regulations that Perry Homes’ detention ponds did not meet. Perry Homes did not:

  • Put 30-foot wide maintenance roads around the ponds.
  • Place backslope interceptor swales around the ponds.
  • Have effective erosion control measures in place.
  • Implement protective measures for their overflow spillway.
  • Prevent increases in downstream flood levels.
  • Prepare a geotechnical report (that they shared with Montgomery County) showing groundwater levels at detention pond sites.
  • Ensure complete drainage of the detention pond.

Detention Pond Falls Short of Promised Capacity

Calculations for the capacity of the detention ponds begin from the bottom of the pond – when empty. When partially filled with water, the calculation begins from the top of the water. The bottom 2-3 feet of S2 has retained water for months, indicating that part of the pond is below the water table. So you can subtract about 20% of capacity that LJA Engineering promised and that Rebel Contractors initially built.

Adding Maintenance Road, Subtracting Backslope Swales

The flurry of work this week centered around creating the maintenance road that regulations demand. Or perhaps Perry is just building up the lip of S2 to compensate for the water it holds. Both are potentially good things.

However, workers also started filling the backslope interceptor swales they previously built. This created a sharp slope next to neighboring residents’ property and increased runoff toward the residents during last night’s rain.

Contractors placing dirt along the southern edge of the S1 pond to build a road earlier in the week.
Elm Grove Trail on left. Woodridge Village on right of silt fence. Note how land is being sloped toward Elm Grove.

An interceptor swale collects water above slopes and diverts it to the bottom of a detention pond through pipes so runoff does not create erosion on the slopes that lead to the pond.

Perry Homes has given no reason why they started filling in the swale they previously built that complied with MoCo regulations.

Looking west from Village Springs Drive. In the foreground, you can see how workers built a road and filled in the interceptor swale between it and Elm Grove on the left.
Still looking west. From this drain pipe, you can better see the grassy swale previously created to drain water into the detention pond (right) and to keep it out of Elm Grove (left).
Reverse shot, looking east. Here you can see how workers filled in the swale and created a road three to four feet high. Residents worry about the effect.
Looking east near the entrance to Taylor Gully from the road, the change in drainage toward Elm Grove (right) becomes very apparent. Picture taken Friday afternoon before rain. Road was uncompacted except for the weight of the small bulldozer spreading dirt (see first picture above).

Same Changes Between S1 and Sherwood Trails

The same changes appear along the southern edge of S1, north of Sherwood Trails, though the road does not appear as high and there also appears to be a shallow swale.

Looking west along the southern edge of Woodridge Village S1 detention pond, toward Woodland Hills from Fair Grove.

No Effective Erosion Control Yet

Perry Homes has also failed to put effective erosion control measures in place in Woodridge Village. For instance, most pond banks do not yet have grass planted on them.

The new road covered up what little grass had grown around the ponds. And raw dirt now fills the former interceptor swale.

A one-inch rain last night swept sediment into the pond, which emptied into Taylor Gully and Caney Creek before joining the East Fork of the San Jacinto.

Massive Pollution

Boater Josh Alberson took the dramatic picture below this afternoon where Caney Creek joins the East Fork. The East Fork water looks natural, but the water coming from Caney Creek via Taylor Gully is clouded with sediment. Woodridge Village is the only large source of exposed earth up Taylor Gully at this time. (Alberson verified that this sediment-laden runoff was NOT coming from the Triple PG mine up White Oak Creek.)

Water from Taylor Gully (right) merging with East Fork water (left) on Saturday afternoon, 1/11/2020, after a 1-inch rain last night.

Posted by Bob Rehak with images from Josh Alberson, Edythe Cogdill and Nancy Vera

865 Days since Hurricane Harvey and 114 since Imelda

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.

What Went Wrong, Part II: Lack of Erosion and Sediment Control Worsen Elm Grove Flooding

On May 7th and September 19th, sediment-laden runoff from Perry Homes’ Woodridge Village development in Montgomery County flooded the streets and homes of Elm Grove Village and North Kingwood Forest. On September 26, the City of Houston wrote a cease and desist letter to Perry Homes, its subsidiaries and contractors. The letter alleged that runoff damaged the City’s sewer system and residents’ homes. It demanded that Perry Homes’ proxies stop sending sediment into the City.

After Imelda, Abel Versa had to grab his car to avoid slipping in ankle-deep sediment on Village Springs. The sediment came from Woodridge Village right behind him.

Sediment Control Measures Not Followed in Subdivision Rules and Regs

If Perry Homes and its contractors had followed all the construction regulations affecting drainage, the flooding of Elm Grove would not have happened and the letter would not have been necessary. So what went wrong? I previously reviewed the sediment control measures in the Montgomery County Subdivision Rules and Regulations. Perry Homes received seven strikes. Among the worst apparent violations:

  • They clearcut 268 acres when the rules say no more than 10.
  • They are supposed to plant temporary vegetation but haven’t.
  • They were supposed to make provisions for increased runoff during construction, but didn’t.

In fact, they have substantially completed only 23% of the permanent detention ponds for the whole subdivision despite clearcutting all 268 acres.

The southern section of Woodridge Village has been cleared, filled and graded since last summer. Grass could have reduced the runoff during Imelda. Photo taken on 11/4/2019.
The northern section has also been mostly cleared for months, though workers are still removing piles of dead trees. This shows the area where they filled wetlands. Because no detention exist for the northern section, runoff from 188 acres is supposed to funnel through a 3′ pipe. That’s not working well in heavy rains. You can see how much loose sediment is exposed to floodwaters.

More Regulations in Drainage Criteria Manual Not Followed

Perry Homes also overlooked many provisions in the Montgomery County Drainage Criteria Manual. Twenty-two of the 175 pages also discuss erosion and sediment control (see Section 6 starting on page 85). Among the more serious omissions:

Channel Slopes Severely Eroding

Section 6.2.1 on Grass Establishment states that: “A good grass cover must be established on all areas within the right-of-way (except the channel bottom) disturbed by channel improvements or by any type of construction. An adequate grass stand on the banks helps stabilize the channel and minimize erosion caused by overbank flow and high velocities in the channel. Establishing a good grass cover requires preparing the seedbed, seeding properly. keeping the seed in place, fertilizing, and watering regularly.

The LJA Engineering report never mentions erosion or sediment control by those words. However, it does mention grass-lined and concrete-lined channels and spillways. Only one problem. The channels are not grass lined and most of the areas designated for concrete lining have yet to be lined.

The banks of detention ponds should be lined with grass. They are not. As a result, sediment is slumping to the bottom of the ponds where it is carried downstream by floodwaters.
This closeup shows how severe the erosion is.

Channel Turns Not Protected

Section 6.2.3 on Minimum Erosion Protection Requirements for Bends specifies that bends in drainage ditches must be protected from erosion by grass, rip-rap, or concrete. The material depends on the radius of the curve, the type of soil, average water velocity and maximum water velocity.

Despite funneling 188 acres of sheet flow into Taylor Gulley, which narrows down into a 3-foot pipe, Perry Homes has done little to increase the channel capacity or detention for that area. Worse, the channel design which may have been adequate for forested wetlands, can no longer handle high volume overland sheet flow.

The most obvious needs are on the eastern side of the development. There, Taylor Gully makes a 120-degree turn, then two quick 90 degree turns and two 45-degree turns, all within two hundred yards. Getting dizzy? The floodwater turns 390 degrees in this area!

At each turn the banks take a beating. The full force of the floodwater slams against the far bank and erodes it.

Photo taken on 11/4/2019 along eastern boundary of the southern section of Woodridge Village. That’s North Kingwood Forest on the right and Elm Grove on the bottom. Little wonder that this was the area hardest hit by flooding in May and September.
Where the channel on the right narrows down into the black 3-foot pipe, contractors built an overflow channel into the detention pond on the left but still have not lined it with concrete. Note the severe erosion. Also note the erosion and sediment coming into the pond on the left just below the flow-constricting device in Taylor Gully. Clearly, there isn’t enough channel capacity to handle the volume of water. Photo taken on 11/4/2019, looking north.

Straight Drop Spillway Not Installed

Section states that a straight-drop spillway should be installed in drainage channels to adjust channel gradients which are too steep for design conditions. 

LJA specifies one between where detention pond N3 will be and the 120-degree turn shown above. However, neither the detention pond, nor the spillway have yet been installed. So water from the north comes barreling down the ditch on the right unchecked. The high velocity increases erosion. Here’s what it looked like after May 7th.

Same area shown above but from ground level and looking south toward Elm Grove. Rain did a lot of the excavating for Perry Homes. But unfortunately, the sediment wound up in flood victims’ homes and the City storm drains.

Yesterday I posted about how Perry Homes was supposed to cut only 30 acres of trees on the northern section but cut 188. Still to come in this “What Went Wrong” Series:

  • More Things Perry Homes Didn’t Do in the Montgomery County Drainage Manual
  • Contradictions in Perry Homes’ Plans
  • The Dirt on Perry Homes’ Soil Test
  • The Floodplain that Wasn’t

Posted by Bob Rehak on 11/20/2019 with help from Jeff Miller

813 Days since Hurricane Harvey and 62 since Imelda

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.