Greeley and Hansen, A TYLin Company, led the Upham Brook stream stabilization and rehabilitation of the 36-inch gravity sewer main.
Originally designed in 1959, this sewer connects to the Upham Brook Sanitary Pump Station wet well and is considered to be part of the City of Richmond’s infrastructure. Over the years, Upham Brook has become incised and has severely eroded its banks, exposing large sections of sewer at multiple locations from Gillespie Avenue to just south of the pump station. Intersecting VDOT drainage from I-95 is causing additional erosion and undermining of the sewer at several locations. Severe stream erosion, undermining, and approximately 400 feet of exposed pipe were observed during field visits. As evident in the field, the water level exceeds the banks of Upham Brook during high flow events and has created a broad floodplain. In comparing the 1959 design plans to recent aerial imagery, Upham Brook has meandered and eroded the southern bank 50-75 feet in some locations along this stretch of sewer.
As part of the City’s Collection System Master Plan, Greeley and Hansen performed a system wide desktop analysis and study of the wastewater collection system near or crossing creeks and other waterways. Field investigations were then conducted to further refine a prioritized list of sewers requiring rehabilitation. The Upham Brook 36-inch sewer was rated as a high priority investigation area, identified as requiring stabilization and protection due to the sewer being exposed to the stream flow and bank erosion. CCTV of the approximately 1,550 linear feet of sewer showed aggregate visible and aggregate projecting as well as sediment and debris build up. Consequently, heavy cleaning and rehabilitation using cast-in-place pipe lining was incorporated into the Upham Brook design.
- Creek stabilization and sewer protection measures
- Bypass pumping of the 36-inch sewer main
- Coordination with Virginia Department of Transportation, Henrico County and the US Army Corps of Engineers