Harris County Flood Control, SJRA, and the Cities of Humble and Houston using funding provided in part by the Texas Water Development Board are searching for sediment solutions in the Upper San Jacinto River Basin. Their major scientific study includes all or parts of seven counties: Harris, Montgomery, Waller, Grimes, Walker, San Jacinto and Liberty – all land draining into Lake Houston.
The high-level goal: to better manage sediment in the river basin. Sediment reduces both floodway conveyance and the storage capacity of Lake Houston. Both contribute to the frequency and severity of flooding.
Among other things, the study partners hope to prioritize sediment hot spots so they can develop sediment solutions and recommendations.
I hope they look at Colony Ridge. It exemplifies a major hot spot and points the way to an obvious sediment solution – better enforcement of existing regulations.
Scope and Status of Sediment Study
The study is now about half complete. With much of the fieldwork complete, the partners will next focus on modeling, hotspot identification, area prioritization and sediment solutions, according to Matt Barrett, Water Resources and Flood Management Division Manager atSJRA.
To date, the study has examined a variety of factors:
- Topographical characteristics (watershed size, length, slope, relief, etc.)
- Land Cover (degree of development, forested percentage, agricultural, wetlands)
- Soil Types and Erodibility
- Meteorological (annual rainfall amounts and intensity).
The Colony Ridge area receives some of the highest rainfall totals and highest intensity rains in the river basin.
Colony Ridge also ranks among the most erodible areas in the entire river basin.
Sediment Solutions Must Address Development Practices
Erosion occurs naturally. But poor development practices can accelerate the rate of erosion unnaturally.
Regulations in Liberty County call for backslope interceptor swales to prevent sheet flow over the sides of ditches. I have yet to see one such system anywhere in the 30+ square miles of Colony Ridge. What you typically see is this.
Liberty County regulations also call for planting grass on the side slopes of ditches and detention basins. The grass reduces erosion, too. But you don’t see much grass on those side slopes either.
Compare the ditch above with the ditch below in Harris County to see how grass and backslope interceptor swales can reduce erosion.
Here’s Colony Ridge again.
Address the Elephant in the Room Before the Next Disaster
Ironically, both Liberty and Harris County have almost identical regulations for erosion control. Harris County enforces them; Liberty County doesn’t.
So, as the SJRA and its partners search for sediment solutions, here’s one simple recommendation. Enforce regulations already on the books.
Colony Ridge and other developments that skirt regulations represent a disaster waiting to happen. Unfortunately, it will probably take a disaster, such as Harvey, to cause leaders to take action. But by then, it will be too late.
Posted by Bob Rehak on 10/20/23
2242 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.