During the month of October 2023, Sprint Sand & Clay excavated another 5,754 cubic yards (CY) of dirt from a new stormwater detention basin on Harris County Flood Control District’s (HCFCD) Woodridge Village property. Compare that to 5,698 cubic yards in September. The new “total to date” is now 156,478 cubic yards. October’s 5,754 CY exceeds Sprint’s monthly minimum of 5,000 CY.
Perry Homes cleared and graded the property for development beginning in 2017. But insufficient stormwater detention capacity contributed to the flooding of Elm Grove and North Kingwood Forest Villages twice in 2019. HCFCD bought the property from Perry in 2021.
Terms of Excavation and Removal Contract
Sprint began excavation in January of 2022 under an Excavation and Removal Contract (E&R). Their E&R contract gives Sprint the right to remove up to 500,000 cubic yards of material for just $1,000. Sprint then makes its money back by selling the dirt at market rates.
E&R contracts often fluctuate depending on home- and road-building activity nearby. They represent good value for taxpayers because they reduce costs. But they also involve some uncertainty in terms of completion dates.
Where Things Stand at End of October
To date, here’s where things stand in relation to possible goals:
|Acre Feet of Stormwater Detention||% of Atlas-14 Requirement||% of Ultimate|
|Site Had When Purchased from Perry Homes||271||70%||47%|
|Has as of 11/1/23||368||95.6%||63.4%|
|Atlas 14 Requires||385||100%||66%|
|If Sprint Excavates All 500K Cubic Yards…||580||150%||100%|
Rain always slows construction activity and it may have played a role during October.
Pictures of Progress
Here are some before/after pictures (in pairs). They show the progress of construction during October.
It appears that most of the excavation occurred at the far end. These three shots show the progress made in that area.
End of October 2023, looking NE
Looking back toward the entrance off Woodland Hills…
How Much Will Be Enough?
HCFCD still has not released the final engineering report for this project. So, we do not know exactly what shape this detention basin will take or what the final volume will be. Regardless, it’s more protection than we had before. And when finished, it will reduce flood risk considerably.
The current rate of excavation when measured in acre feet is about 3.6 per month. That means Sprint would reach the volume required to meet Atlas 14 requirements in about 5 months – the end of the first quarter in 2024. It’s unclear at this time how much HCFCD will have Sprint go beyond that.
NOAA is already working on Atlas 15. Atlas 15 will incorporate the effects of climate change in the national precipitation frequency standards for the first time. NOAA expects estimates to increase. So the size of this detention basin could, too.
NOAA expects to release the new data for peer review in 2025 and the final study in 2026. After that, NOAA will update the precipitation frequency estimates no less than once every ten years.
There is no such thing as certainty when predicting the future. The good news? There’s plenty of room on this site to expand stormwater detention volume in the future.
Posted by Bob Rehak on 11/1/2023
2255 Days since Hurricane Harvey and 1505 since TS Imelda