The hardest hit area from Tuesday’s storm seemed to be one that never flooded before: Elm Grove Village. Media have reported as many as 400 homes flooded there. As I drove down Elm Grove streets near the Harris/Montgomery County line, home after home had waterlogged trash, carpet, mattresses and furniture piled in front. Suddenly, I had eerie flashbacks to Harvey. Clusters of people in the street trading horror stories. Service trucks everywhere. Residents gaping at damage, consoling each other. People crying as they threw out prized belongings. Shock, sympathy, anger, fear all rolled into thousand-yard stares. Wondering what would come next with 8-12 more inches of rain on the way. But most of all, they were asking “Why?”
Here’s what I’ve been able to learn.
- According to the residents I talked to, this area never flooded before…even during Harvey.
- The storm drains were clear. City Councilman Dave Martin who was onsite this morning coordinating the City’s response showed me fiber optic video of clear storm sewers. Public Works could find no blockages near the flooded homes in Elm Grove.
- Drone footage (below) shows there were no blockages in the ditch that services the area.
- The rainfall intensity and duration on Tuesday both played a roll.
- According to Martin, storm drains in this area are designed to handle 1/2 inch of rain per hour. However, Elm Grove received close to 10 inches during a 5 hour period on Tuesday.
- A complicating factor was a new subdivision being built in Montgomery County (by a subsidiary of Perry Homes, Figure Four Partners LTD) that butts up to Elm Grove.
- The developer clear-cut 92 acres and slanted drainage toward Elm Grove.
- No detention ponds, silt fences, berms, sand bags, or filter socks had been installed to retain water that I could see. Also, with the exception of one or two small groves of trees, no vegetation remained to slow or absorb runoff.
- The developer covered up an existing stream/ditch according to residents.
- Near the end of a long, severely eroded drainage ditch, the developer installed a box culvert that couldn’t handle the volume from this storm. It backed water up and flooded the site according to residents.
- The overflow then went into Elm Grove.
- According to residents, construction employees routinely access the site from Elm Grove streets. Their trucks created ruts that channeled water into the streets.
- Because the storm drain capacity could not keep up with the rainfall rate and the water flowing from the development, water rose in the streets and flooded homes. Most people I talked to had 12-18 inches of water in their homes.
The Difference? The New Development
Storms as intense as Tuesday’s have happened before without flooding in Elm Grove. Heck, not even Harvey flooded the area. No blockage existed in the sewer or the existing drainage ditches in Elm Grove. Clearly, the one thing that’s different in this equation is the new development.
Drone Stills from Jim Zura
View from the Ground
Family Closest to the Problem
Within the next day or two, I hope to edit the drone footage with the talented Jim Zura who shot it. As I post this, I hear thunder outside from yet another round of storms. And I’m praying for the people of Elm Grove.
Posted by Bob Rehak on 5/9/19
618 Days since Hurricane Harvey