Stormwater Control Structures

Program Overview

The City of Chattanooga requires measures to treat and maintain stormwater runoff. This requirement comes directly from the City's NPDES Permit. The Water Quality Program inspects stormwater treatment structures (also called stormwater BMPs) within the City to ensure that they are working properly.  Stormwater treatment structures that are maintained correctly prevent pollutants from entering the City's streams and creeks that eventually drain to the Tennessee River. Stormwater BMPs also act as a method of flood control by detaining excess stormwater runoff and discharging it at a slower rate. This prevents the City's Municipal Separate Storm Sewer System (MS4) from becoming overloaded during rain events and also prevents streams from being overwhelmed with a high volume of stormwater runoff which can erode its banks. 

Stormwater BMPs come in a variety of different types. The most common structures in the City are detention ponds and oil/grit separators. There are also media filters, retention ponds, constructed wetlands, and a variety of underground water quality units.  All of these structures are aimed at removing pollutants from stormwater runoff before the water is discharged into the City's MS4 which eventually leads to the Tennessee River.

The goal of the Stormwater Controls division of the Water Quality program is to monitor and document existing structures as well as monitor and document any new structures that are built in the City. Stormwater Controls Inspectors also give advice on how property owners can better maintain their stormwater BMPs to maximize their abilities.