Tag Archive for: drainage systems

Karma Strikes Again: Colony Ridge Drainage Systems Severely Eroding

October 8, 2023 – Karma is fast catching up with the corner-cutting Colony Ridge developer in Liberty County. Drainage infrastructure that doesn’t meet Liberty County regulations is fast eroding.

And tomorrow, a special session of the Texas legislature will start investigating the embattled development. The special session will focus on crime, infrastructure, illegal immigration, and more.

To offset negative publicity, the developer invited legislators to meet at his development last week and tour it.

But just before the meeting, Liberty County deputies, a narcotics unit, and SWAT team responded to an abduction at gunpoint. They also launched a manhunt for two escaped suspects in the sprawling development, which is now 50% larger than Manhattan.

On the day of the developer’s meeting, the main entrance to the development flooded. Badly. Ditches designed to keep roads clear in a 5-year storm overflowed during a 1-year rain.

The next day when the storm clouds cleared, an aerial survey showed that Colony Ridge drainage channels and stormwater detention basins were badly damaged.

Had the developer simply followed Liberty County regulations, he could have reduced or avoided the costly damage.

Missing Erosion Controls

Section 50 of Liberty County’s Subdivision and Development regulations specifies requirements for construction of drainage ditches and stormwater detention basins.

The County emphasizes the need to control erosion and sedimentation. It warns these twin threats can have very serious effects on stormwater ditches and basins. Specifically, they can:

  • Cause slope failures
  • Reduce the efficiency of drainage channels
  • Clog drainage culverts
  • Reduce channel capacity
  • Reduce maintainability of drainage facilities
  • Increase maintenance costs
  • Require more frequent repairs
  • Increase turbidity
  • Impair water quality.

To counter these problems, the regulations say…

“Interceptor structures and backslope swale systems are required to prevent sheet flows from eroding the side slopes of open channels and detention facilities.”

Liberty County Subdivision and Development Regulations, Page 100

The diagram below explains how they work.

backslope interceptor design

The regulations also specify design requirements for these structures and other erosion control measures. Altogether, Colony Ridge apparently violated requirements for:

  • Backslope interceptor and swale systems
  • Bermuda grass on side slopes of channels and ditches
  • Erosion controls around outfall pipes
  • Geo-textile bedding under rip rap
  • Pilot channels at the bottom of detention basins
  • Maintenance strips
  • Storage of excavated dirt
  • Side-slope angles

Not all locations in Colony Ridge exhibit all problems. Regardless, karma was swift. Thursday’s 1-year rain severely eroded the side slopes of channels and basins. Eroded sediment also started filling in new ditches and basins.

Repairs and compliance – if attempted – will be costly and time consuming.

Karma Hurts Residents Upstream and Down

While critics might rejoice at the karma, others will pay the price. The developer’s practices increase flood risk for people in Colony Ridge as well as those downstream.

  • In the development, erosion threatens property.
  • Downstream, sediment reduces the conveyance of streams, increasing flood risk.

TCEQ has warned the developer about his construction practices before. But many dubious practices continue. See photos below.

The first two are NASA satellite images from Google Earth. I shot the rest on 10/6/23 with one exception.

Threat to Colony Ridge Residents

When a three-mile ditch down the center of Colony Ridge was completed, it was about 120 feet wide at the yellow line.

August 2017

Today, it’s 76 feet wider.

Residents on EACH side lost 38 feet of their back yards.

This ditch has steadily widened since its construction. Without backslope interceptor swales or grass to reduce erosion, millions of cubic feet of dirt swept downstream from this single ditch.

Then, when the water slowed at the headwaters of Lake Houston, the sediment dropped out of suspension, reducing the conveyance of the East Fork San Jacinto.

Here are several shots showing what that erosion damage looks like up close from a helicopter.

The ravine forms more ravines.
No room for a maintenance road here.
Or here.

Virtually every ditch in Colony Ridge has erosion and compliance problems. Here’s another one.

No maintenance road. No backslope interceptor swales. No grass on sides of ditch. Note: home on right has no back fence. What happened to it?
Note piles of dirt stored where they can erode back down into ditches.

Even detention basins in the newer sections of Colony Ridge have erosion problems. Again, most don’t have grass on the side slopes. Nor do they have backslope interceptor swales. Many, like the one below, don’t have room for maintenance roads.

Note the erosion threat already to these recently placed mobile homes in a newer section of Colony Ridge.
Erosion will soon threaten one of the new roads in Colony Ridge. Regs specify that rip rap like you see here should have had a geo-textile lining under it to reduce erosion.
Erosion washed sediment into new basin. Also note how erosion is starting to block the outfall at the lower right.
No backslope swales here. Not much Bermuda grass either. Regs say “side slopes shall be no steeper than 3 horizontal to 1 vertical (3:1).”
No grass or backslope interceptor system here. No pilot channels either.
Note piles of excavated dirt stacked on both sides of road, eroding back into ditches.

As all those ditches and basins gradually fill in, they will add to future flood risk.

But repairing such issues will be a big, costly challenge – one that the developer has ignored for years.

Threat to Downstream Residents

All this erosion also contributes to downstream flooding and likely violates Section 11.086 of the Texas water code. It states that “No person may divert … the natural flow of surface waters in this state … in a manner that damages the property of another…”

Where does all that eroded sediment eventually go? To Lake Houston, of course.

East Fork San Jacinto downstream from Colony Ridge on Thursday 10/5/23 – same day as shots above.

The river slows down where it meets the headwaters of Lake Houston. That causes sediment to drop out of suspension.

Harris County, City of Houston and the State just finished a major dredging effort on the East Fork that cost the public tens of millions of dollars.

Before dredging, it looked like this.

East Fork Mouth Bar after Imelda and before dredging. This bar grew 4,000 feet between Harvey and Imelda.

But the cost is only part of the issue. Reduction in the river’s conveyance contributed to the flooding of thousands of nearby homes during Harvey and Imelda.

Harris County Commissioners Court May Address Issues on Tuesday

Drainage is a public-safety issue. And it’s not the only one caused by the developer’s disregard for regulations.

  • Colony Ridge has filled in wetlands.
  • TCEQ has also documented problems with the Colony Ridge sewage system that led to a 48,000 gallons of fecal matter escaping into Lake Houston, the source of drinking water for 2 million people.
  • Colony Ridge does not have enough fire hydrants or water pressure to comply with the Liberty County fire code.

Harris County Commissioners Court may discuss these problems on Tuesday at the request of Precinct 3 Commissioner Tom Ramsey, PE. See Item 406 on the Agenda.

The developer alleges that racism motivates criticism of his Hispanic development. But racism does not explain flooding, feces and fire.

The failure of a developer to follow regulations shouldn’t pit Liberty County against Harris County, rich against poor, or Democrats against Republicans.

We all suffer equally. We all face increased risk. And Colony Ridge is one issue where we should all find common cause.

I hope that Commissioners Courts in both counties support the legislature’s investigation into Colony Ridge. I also pray that both Counties can work together to protect all residents.

Posted by Bob Rehak on 10/8/23

2231 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.