Athens, Ga. Stormwater Detention Pond Outlet Faces Severe Erosion

Athens, Ga. | Retail | Stormwater System Repairs

Overview

This Athens, GA store is determined to give its customers the best products at the lowest costs. They have been a staple in the community for doing just that.

Problem

In Athens, GA, a retail store’s stormwater detention pond outlet was affected by substantial erosion. Trees surrounding the area had grown too large for their proximity to the outlet. Overgrown trees allowed roots to entangle themselves with the outlet pipe as the tree continued to grow. The roots grew with time and cracked the pipe and eventually caused a washout and collapse of the pipe.

A section of pipe approximately 20 feet of 60 inches in size became detached entirely. The detached pipe allowed water to flow freely over unprotected soil, leading to the massive eroded area. During heavy rain events, erosion patterns caused water to swirl in front of the outlet, which led to intense erosion at the drainage point and compromised the entire area’s soil integrity. Due to the severity of the damage, AQUALIS concluded that the entire slope would need to be reconstructed to ensure stabilization. The store was able to alert AQUALIS via emergency response to avoid further damage and conduct a review of assets to ensure repairs were completed in a timely and efficient manner.

Before

After

Solution

AQUALIS coordinated with property owners, reviewed the plans, and begun action to ensure no further damage was inflicted on the assets. AQUALIS experts knew the first step was to remove the source of the problem, overgrown vegetation. Trees were cut down, and vegetation in the immediate area was removed, stumps and root systems included. Clearing of vegetation was done to ensure repair efforts would not be subdued by roots in the same way as the original pipe and to allow proper reconstruction of the area. While vegetation is often beneficial to stormwater systems when properly maintained, if left unchecked, problems like this arise as root systems expand.

Once the area was cleared, the pond had to be drained to allow pipe access, inspection, and proper rehabilitation. Draining of the pond was done to ensure the best installation and worker safety.

Next, sediment and debris were removed from the eroded area. Any good dirt, referring to dry and compatible soil, found was saved and used later in the reconstruction, minimizing costs by utilizing what was already available on site.

Reshaping and grading then prepared the outlet area for dredge sox, rocks, and the new pipe. The soil was compacted every 2 feet for stabilization until built grade was met. Geo-textile liner and riprap were used during the rebuilding of the outlet to ensure stability and minimize future erosion as preventive measures. Both materials help support soil integrity and soil’s ability to absorb water. A new headwall was constructed to thwart vegetation growth and erosion, minimizing risk from future root systems. Once the slope was completely reshaped, any areas of concern were stabilized with love grass and erosion control blankets.

Finally, any disturbances to the pond were repaired, fencing was reinstalled, and the area was seeded with Love grass and Juniper. These plants allow for erosion control, but their root systems are too thin to pose a risk to the newly installed pipe.

This location now has many layers of defense against erosion and, with proper maintenance, should never face severe erosion again. This location is maintained with AQUALIS services for frequent visits to manage vegetation growth and inspect structures to ensure a long-life cycle for the new SCMs.