Free OUTfallin': Incorporating Outfalls into Resilient Stormwater Solutions
Timmons Group has had the opportunity within the last year to support our municipalities with fixing unstable stormwater outfalls of varying severities. We will share why early and often inspections for these outfalls, located in dynamically developing watersheds, is vital for municipalities maintaining these stabilization measures. We will also stress the importance of designing for long term stability and keeping maintenance in mind for both designers and developers. We’ll compare multiple outfall stabilization measures from the simple to the complex spanning multiple projects. Stable outfalls are critical for both stream health and infrastructure protection. One constructed project we’ll highlight exhibited an extreme terrain elevation difference with a drop of 30’+ from outfall pipe to floodplain and had a 30’ eroded gully exposing a sanitary manhole and pipe system. This led to the need for temporary sanitary pumps that brought high operation costs for the municipality until the site could be restored. Another site has multiple outfalls near homes and a roadway with 12-14’ vertical banks at the outfall channel and others where the road itself is being overtopped from these outfalls in large storm events. These outfalls and others emphasize the importance of catching outfall issues early to minimize impact and cost in restoring site conditions and creating functional and long-lasting outfalls. Timmons Group has been able to work with municipalities to provide beneficial solutions to the affected properties littered with significant site constraints while emphasizing the need for diligent maintenance and inspection moving forward.
Author Bio
Alston is a Project Engineer for the Stormwater Services Group in North Carolina at Timmons Group. He has experience in analyzing and designing a multitude of water resources projects. He specializes in stream morphology and stream design with level 1-4 Rosgen certifications but also provides support on a variety of stormwater projects that Timmons Group gets involved with across North Carolina and Virginia. He graduated from North Carolina State University with a bachelor's in Biological and Agricultural Engineering. Jacob is a Project Engineer for the Stormwater Services Group in North Carolina at Timmons Group. He specializes in hydrologic and hydraulic modeling, stormwater management, drainage analysis, stream design, and roadway improvements. He graduated from North Carolina State University with a bachelor's in Environmental Engineering.
