On Sunday morning, Jeff Miller, an Elm Grove resident who lives near Woodridge Village, reported 5.5 inches in his rain gage. That compares to a 6.24 inch rain that fell on Woodridge on May 7, 2019, when hundreds of homes in Elm Grove and North Kingwood Forest flooded. Also, Woodridge falls about 40% short of current Atlas-14 standards required to hold back floodwater from a 100-year storm.
So you can understand how nervous Elm Grove and North Kingwood Forest residents felt, especially considering that excavation of additional detention ponds on Woodridge Village has not yet started. Regardless, Woodridge did not flood homes across the county line this time. Here’s why.
Important Factors to Consider
Other important factors came into play last weekend that should relieve some of residents’ anxiety and help explain what happened.
First, remember that on May 7, 2019, Perry Homes’ contractors had clearcut 268 acres, but had barely begun work on detention ponds. Only one of five was complete.
Second, the intensity of the May 7, 2019 rain was higher than last weekend’s. On May 7, 6.24 inches fell in 5 hours. Last weekend, 5.5 inches fell in 9 hours.
Third, in 2019, the S2 detention area had been partially excavated but didn’t have any outflow control restrictions installed yet. So it didn’t really function as a detention pond.
Fourth, contractors had destroyed a berm between Elm Grove and Woodridge, and filled in a natural stream on Woodridge. Both have since been replaced.
Fifth, by current standards, last weekend we had a 5-year storm. But the detention ponds were designed to hold what today would be classified as a 25-year storm.
Photos Taken Sunday Morning
I took the photos below Sunday morning between periodic sprinkles, several hours after heavy rain stopped. They show how the current Woodridge Village detention handled the storm. All ponds were well within their banks. One was empty.
Big Test and Additional Excavation Yet to Come
So the Perry-installed detention passed another test. But it was far from what college students would call a final exam.
Flood Control purchased this site last year and plans to turn it into a regional detention basin by more than doubling the detention capacity. However, the excavation contract lets the contractor take the dirt when it can be sold, while only meeting minimum monthly requirements which have not yet kicked in.
Posted by Bob Rehak on 1/11/2022
1596 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.