Chevrons are essentially small check dams installed along street gutters that act as both an erosion control and sediment control. They usually consist of several gravel or sand bags arranged in an L shape along a curb. The presence of chevrons helps to slow water velocity, which allows suspended sediment in water to settle. This reduces water’s turbidity and helps prevent costly exceedances. Installing chevrons prior to a rain event is a quick and easy way to help your site’s water stay in compliance.
Using a series of chevrons is more effective than just using one. Typically, chevrons are placed every 15-20 feet, allowing small pools to form behind each chevron. As the water flows through each chevron, it becomes progressively cleaner.
Chevrons should be inspected periodically, especially before, during, and after rain events. Be sure to replace broken bags and clean the sediment that accumulates behind the chevron in order to maintain its effectiveness. Chevrons may need to be altered or removed if excess ponded water creates a safety hazard.