At the end of June, stormwater detention basin excavation on Harris County Flood Control District’s (HCFCD) Woodridge Village property reached 92% of Atlas-14 requirements. When HCFCD bought the property from Perry Homes in 2021, it had only 70% of the required detention capacity under Atlas 14.
Atlas-14 defines the current standard for safely containing a 100-year rainfall. The lack of detention basin capacity contributed to the flooding of hundreds of homes along Taylor Gully twice in 2019, after Perry contractors clearcut the property.
June/July Photos Show Progress
The first photo below was taken at the beginning of June 2023 so you can see how much progress has been made in the last month.
The second shows the site at the beginning of July 2023. The primary changes seem to be additional depth and length.
HCFCD spokesperson Amy Crouser said that, “Essentially, the contractor is free to excavate where they want within the provided footprint.”
Where Does Woodridge Village Excavation Go From Here?
HCFCD’s Excavation and Removal contract with Sprint Sand & Clay calls for excavating up to 500,000 cubic yards. Sprint excavated approximately another 8,000 cubic yards in June. That equals approximately 5 acre feet.
If Sprint keeps excavating at that rate, the table below shows that it could reach Atlas 14 requirements by the end of this year.
However, Sprint’s contract calls for excavating UP TO 500,000 cubic yards. Any excavation beyond Atlas-14 needs would create a safety hedge against future needs should they increase.
NOAA is already working on updating the Atlas 14 requirements and should release Atlas 15 before the end of this decade.
Here’s how all that looks in a table.
|Acre Feet of Stormwater Detention||% of Atlas-14 Requirement||% of Ultimate|
|Site Had When Purchased from Perry Homes||271||70%||47%|
|Has as of 7/1/23||353||92%||61%|
|Atlas 14 Requires||385||100%||66%|
|If Sprint Excavates All 500K Cubic Feet||580||150%||100%|
Sprint will make only $1,000 from its Woodridge Village excavation contract with HCFCD, but will make its profit by selling the dirt at market rates. It’s a good deal for taxpayers, but carries some uncertainty with it.
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.
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. Engineers are reportedly working on plans for all that, according to HCFCD.
Posted by Bob Rehak on 7/1/2023
2132 Days since Hurricane Harvey