Woodridge Village Excavation Approaching Atlas-14 Requirement

Harris County Flood Control District’s (HCFCD) Woodridge Village Excavation and Removal contract with Sprint Sand & Clay continues progressing nicely. The volume excavated last month shows a continued rebound in activity after a dip last year when the housing market slowed.

As of the end of April, Sprint has completed approximately 23% of its 500,000-cubic-yard contract. More important, excavation could meet Atlas-14 detention requirements by the end of 2023.

Sprint excavated an estimated 11,000 cubic yards in April – more than double the monthly minimum. That brings the total to date to approximately 115,000 cubic yards.

Photos Reveal Excavation in New Direction

Here’s what the status of Woodridge Village excavation looked like on 5/1/2023. For the last year, Sprint has focused on lengthening the basin. Now it is focusing on widening it, too. Note the work taking place in the upper left quadrant of the photo below.

Typically, HCFCD gives E&R contractors some general boundaries and says, “Start digging.” Sprint makes its money by selling the dirt on the open market. There’s virtually no cost to taxpayers. And usually the bigger the hole in the ground, the better. So, according to a former flood control executive, if Sprint goes beyond 500,000 cubic yards, no one will complain. It reduces flood risk free of charge.

But where is all this headed and why?

Past, Current and Future Capacities

When Perry Homes sold the Woodridge Village property to HCFCD in 2021, it had five stormwater detention basins with a total storage capacity of 271 acre feet. But because Montgomery County issued construction permits based on pre-Atlas-14 requirements, the development was approximately 42% short of meeting current Harris County standards.

Partially as a result of insufficient stormwater detention capacity, up to 600 homes downstream in Kingwood flooded twice in 2019.

After HCFCD bought the property, it hired Sprint to get a head start on Woodridge Village excavation of additional detention capacity while it worked out exact plans for a regional detention basin and Taylor Gully.

Sprint has excavated approximately 71 acre feet so far. That brings the current detention capacity to 342 acre feet.

But HCFCD will ultimately need approximately 385 acre feet of stormwater detention capacity to meet Atlas-14 requirements and it hopes to build even more as a safety hedge against future needs should they increase.

If Sprint excavates the entire 500,000 cubic yards in its contract, that would bring the total stormwater detention capacity up to 580 acre feet. In tabular form, the steps look like this:

	Acre Feet of Stormwater Detention	% of Ultimate
Site Had When Purchased from Perry Homes	271	47%
Has as of 5/1/23	342	59%
Atlas 14 Requires	385	66%
If Sprint Excavates All 500K Cubic Feet	580	100%

Calculations in the last column assume that Sprint excavates all 500,000 cubic yards. But Sprint’s contract calls for excavating UP TO 500,000 cubic yards.

A lot of flexibility exists for both parties in an E&R contract. If the demand for dirt dries up and excavation slows, HCFCD and Sprint could modify the E&R contract to complete a smaller detention basin sooner. But I assume it would still meet Atlas 14 requirements at a minimum.

Based on April performance, Sprint is currently excavating approximately 6 acre feet per month.

If demand for dirt holds, excavation should reach Atlas-14 requirements near the end of 2023.

Still Much More Work to Do

But simply excavating the dirt isn’t the end of the job. Harris County still needs to slope the sides, plant grass, and tie the new basin into the site’s existing stormwater-detention-basin network.

An engineering team is currently working on drawing up final construction plans. Simultaneously, they are looking at how Woodridge Village excavation will impact Taylor Gully needs.

At the moment, no one knows exactly how this project will end. There are simply too many variables. The site could contain one giant stormwater detention basin or several smaller ones.

HCFCD often employs a phased approach with large projects, such as Woodridge/Taylor Gully. Consider for instance, Willow Water Hole on South Post Oak at Highway 90. Or the Lauder Basin on Greens Bayou south of Beltway 8 North.

A phased approach enables residents to start reaping partial benefits sooner, with an eye toward maximizing future risk reduction as circumstances and funding allow.

Posted by Bob Rehak on 5/2/2023

2072 Days since Hurricane Harvey and 1329 since Imelda