Harrison Branch (E Columbia St. / E Jefferson St.)
Design Phase (Summer 2021)
Conceptual design was completed in March 2021. Final design is anticipated to finish by January 2023, with construction starting later that fall.
About the Project
The Harrison Branch, a tributary that outfalls to Four Mile Run, flows under the E Columbia Street neighborhood. The existing drainage system is severely undersized for the neighborhood’s catchment area: a single drainpipe serves a neighborhood of over 100 homes on a downward sloping 71 acres. Since 2018, approximately 48 homes have experienced flooding to some extent; 8-10 of these homes deal with some sort of flooding after any sort of rainfall. Stormwater related damage and frequency is worsening due to development of much larger homes on average size lots (including “pipe stem homes” or shared driveway homes), home add-ons, and tree cover loss, all of which reduce the neighborhood’s surface area for water absorption and exacerbates the stress of the existing drainage system. During major storms, both E Columbia St. and E Jefferson St. experiences severe road flooding, creating public safety hazards for vehicles and pedestrians.
Proposed project work includes installing a larger stormwater sewer pipe, adding and expanding yard inlets, and grading modifications. The Harrison Branch Stormwater project in particular faces several challenges, including conducting work in FEMA regulated floodplain and resource protection areas, significant work on private property, and existing utility conflicts.