Permanent Outfall Solution
Houston’s heavy, and unpredictable rain events can wreak havoc on stabilization efforts, creating costly erosion issues when proper controls are not put in place.
Take a look at the 2 pictures below. This type of outfall is a large swale that runs a distance of approximately 550 feet from one end of the site to the detention pond.
Because a BMP was not put in place at the end of the swale, the slope began to develop reels and cave in; creating not only a safety concern, but also an unsightly hole in the ground that will have to be regraded. Placing a BMP at the end of the swale would have helped control the amount of water runoff that the slope was exposed to.
To correct this issue, we chose to install a rock filter dam at the end of the outfall. A layer of nonwoven geotextile fabric was placed on the ground to help prevent soil from seeping into the rock. We then laid down wire and wrapped the bull rock inside to contain it and prevent it from moving. This erosion control practice has slowed down the flow of water, alleviating the force on the slope.
Sometimes a few extra steps are all that is required to prevent expensive failures.