Approximately 2,900 feet east of Old Hammond Highway’s intersection with Airline Highway is a box culvert at Harrelson Lateral, which is causing conveyance constrictions. As a result, the stream bank is at risk of over-topping and flooding the surrounding area. This project focuses on enlarging the box culvert.
Box Culvert on Harrelson Lateral at Old Hammond Highway
Existing 100-Year Floodplain
Proposed 100-Year Floodplain
The photo on the left shows the current flood conditions for this location if a 100-year storm event were to occur. The photo on the right shows the conditions for this location for a 100-year storm event if the box culvert were replaced with a larger culvert. If left in its current condition, this stream will overflow its banks, and flood residential areas south of Old Hammond Highway. To avoid these damages, a larger box culvert will be constructed, which will increase channel flow and reduce flooding near this location.
The total cost of this project is $1.05 million, with 75% of this funding from the FEMA Hazard Grant Mitigation Program. This funding is supplemented with East Baton Rouge’s local match of 25%, which will be paid for by the Louisiana Watershed Initiative. The enlarged box culvert on Harrelson Lateral will protect residential areas south of Old Hammond Highway from damaging flood waters.