Johns Creek addresses Old Alabama stormwater erosion

The existing stormwater pipe adjacent to Old Alabama Road in Johns Creek has no headwall. Without a headwall to properly handle the velocity of the water exiting the pipe, the ground under and around the pipe has become heavily eroded. (Courtesy City of Johns Creek)

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The existing stormwater pipe adjacent to Old Alabama Road in Johns Creek has no headwall. Without a headwall to properly handle the velocity of the water exiting the pipe, the ground under and around the pipe has become heavily eroded. (Courtesy City of Johns Creek)

As part of Johns Creek’s commitment to improving stormwater infrastructure, the city recently approved contracts for the extension of a stormwater culvert adjacent to Old Alabama Road.

The city agreed to a $447,998 construction contract with Summit Construction and a $40,000 task order for engineering and inspection services with Wood PLC to help prevent further erosion at the existing culvert discharge and shore up the stability of the roadway slope.

The existing stormwater pipe just northwest of Autry Falls Way has no headwall. Without a headwall to properly handle the velocity of the water exiting the pipe, the ground under and around the pipe has become heavily eroded. The result is called a “perched” stormwater culvert because the pipe end perches or hangs above the surrounding area.

This project is designed to extend the culvert, add a headwall, and re-grade and re-slope the land adjacent to the stormwater pipe. Shoring this area up will reduce further erosion from occurring.