Engineering Diagrams for Woodridge Development Reveal Crucial Detention Not Installed Before Elm Grove Flood

Late yesterday, I received engineering and drainage plans for the new development north of Elm Grove called Woodridge Village. They show that the developer had planned detention that was not yet installed when last week’s heavy rains hit. This helps explain why water overflowed into the streets of Elm Grove and North Kingwood Forest instead of staying on the developer’s land – where it should have been – until it could be released at a controlled rate into Taylor Gully.

Figure Four Partners, LTD, a subsidiary of PSWA Inc. and Perry Homes, is the developer of approximately 262 acres. Rebel Contractors completely clear cut the entire area before building required – and as it turns out, crucial – stormwater detention.

Plans Differ from Execution

Plans clearly show a huge detention/retention pond that should have been in the southeast part of the property near Elm Grove and North Kingwood Forest. Its purpose: to capture runoff from the north and west. The plans also show a diversion of water from the existing ditch that borders the eastern side of the property into the non-existent detention pond.

This isn’t the only detention missing on the property. The northwest pond is also non-existent at this writing.

Photographs taken last week after the rains show that the southwest ditch overflowed where it narrowed down into a two foot pipe. Water then rushed overland into North Kingwood Forest on the east side and Elm Grove on the west. Where the detention pond should have been, one could see large erosion channels approximately one to four feet deep.

Here’s how the drainage works for the entire development.

Note that the direction of flow is generally from north to south and west to east.

Here’s a close-up of the area where a large concrete detention pond should have been. See red circle.

Not-yet-constructed detention pond was designed to capture water from the north and release it through a culvert into Taylor Gully. Approximate area for detention pond was 2 acres. Plans show pond was intended to be 15 feet deep. Thus, this one pond could have and should have retained approximately 30-acre feet of runoff, much of which wound up in the streets of Elm Grove.

Storm Hits Approximately Six Months after Clearcutting

Here’s what the area of the not-yet-constructed detention pond looked like after the storm.

Looking southwest toward the culvert. Abel Vera’s home is just beyond the tallest tree on the left. He and his neighbors up and down Village Springs suffered extensive damage from the water that was not retained on this site.

Below is what it looks like from the opposite direction, when you stand with your back to Elm Grove and Vera’s home.

According to the plans, almost everything between the camera position and the telephone poles in the background should be a 15-foot deep detention pond.

This discovery raises a question. Why did developers wait so long to install the proper detention? Satellite images from Google Earth show that this portion of the site was cleared sometime between 10/28/17 and 12/22/18. Residents say it was substantially cleared by November of 2018.

Developer’s Own Plans Contradict Its Statements

That means it sat clearcut without the required detention for about six months.

Figure Four Partners, LTD said in a statement released after the flood that their detention was installed AND that it functioned as planned. Figure Four’s own plans and these photos tell a different story.

Figure Four’s statement also said the rainfall was as so intense that it should be called an Act of God. Harris County Flood Control later released a statement saying the rainfall was between a two and 50-year event.

Posted by Bob Rehak on 5/15/2019, with a heads-up from Jeff Miller

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Thoughts and conclusions expressed in this post of my opinions on matters of public policy and safety. They are protected by the First Amendment of the U.S. Constitution and the Anti-SLAPP statutes of the Great State of Texas.