NTM Engineering was part of an AKRF team restoring and enhancing Reaches 4 and 5 of the Tacony Creek Park’s ecosystem. As part of its restoration and green initiatives, the Philadelphia Water Department intends to restore the Tacony Creek stream corridor, which extends from Cheltenham Avenue on the upstream extent down to Castor Avenue on the downstream extent. Tacony Creek is an impaired, urban stream subject to regular combined sewer overflows and flashy hydraulics. The project’s goals were to:
- Provide for public health/safety, while enhancing recreational and natural experiences for visitors
- Strengthen the links among the park and its neighborhoods via green infrastructure gateways
- Reduce sediment accumulation and downstream scour at bridges
- Improve the corridor’s habitat quality and diversity and the Creek’s water quality
- Protect existing infrastructure and limit new structures
- Utilize green designs and materials and reduce life-cycle impacts
- Preserve, protect, and interpret historical features within the park
- Avoid increases to the 100-year floodplain and provide additional flood storage
NTM developed the project’s hydrologic and hydraulic (H&H) model and determined the Creek’s inflow hydrographs and combined sewer overflow and surface water discharging into the project area. Since NTM personnel helped to develop the Tookany/Tacony/Frankford Creek Act 167 Stormwater Management Plan, our engineers were very familiar with the watershed’s existing modeling and data. NTM created a 1D hydraulic model that integrated both reaches. Bridge and structure data was acquired. Project survey data provided the channel and floodplain topography and structure geometry. Our hydraulic engineers determined Manning’s n values in the field. Water surface profiles were modeled for a range of flows, including 1-, 1.5-, 2-, 5-, 10-, 25-, 50-, and 100-year recurrence interval flows. Velocity distributions were then developed to assist with the stream restoration.