The Bellefonte Area Industrial Development Authority (Bellefonte IDA) worked with BH to redevelop the waterfront district located in historic downtown Bellefonte, a key component to the overall development of the downtown. The project included a pedestrian walkway along, and bank stabilization of Spring Creek and flood protection of the adjacent area to create suitable land for redevelopment. In order to make the site developable, the area adjacent to the Creek needed to be raised above the 100-year floodplain elevation. A Waterfront District Revitalization Plan was developed, and the project was championed by the Pennsylvania Redevelopment Assistance Capital Program in July 2011 with a funding grant of three million dollars.
The Bellefonte IDA Flood Control and Waterfront Redevelopment Project site is situated within the land located between Spring Creek and Dunlap Street in the Borough of Bellefonte, Centre County, PA. The site is approximately 4.6 acres, with dimensions of approximately 1,130 feet long (north/south) 195 feet wide (east/west). The site is a former commercial and industrial area. A small structure, formerly a railroad building, is situated on the site.
Spring Creek is listed as a High Quality Cold Water Fishery (HQ-CWF) under Chapter 93-Water Quality Standards of the PA Code and designated as a Class A Wild Trout Stream by the PA Fish and Boat Commission.
The primary purpose of the Bellefonte IDA Flood Protection and Waterfront Redevelopment Project was to stabilize the stream and to flood proof portions of the project area to create suitable land for economic redevelopment. During review and consideration of the historic attributes of the site, BH evaluated the existing wall for reconstruction/repair, but found it to be unfeasible for structural reasons.
The three existing structures on the site are within the 100 year floodplain and therefore are not conducive to reuse. The portions of project are to be flood-proofed will receive fill ranging from five (5) to eight (8) feet. Approximately 30,000 cubic yards (cy) of fill will be required to flood proof the area.
The primary component of the project consisted of the removal of the western existing wall/foundation bank along Spring Creek and replacement with a concrete segmental retaining wall. The proposed design included vegetating the banks above the stream bank wall with a riparian buffer native seed mix, the construction of a pedestrian walkway behind the new retaining wall/vegetated stream bank, and the construction of a retaining wall to the west of the pedestrian walkway allows for the remaining portion of the project site to the west to be raised to elevations that exceed 1.5 feet above the 100-year flood level. No fertilizers were used for plant establishment along the stream bank . In the area where the existing earthen bank will be maintained, exotic plant material was removed and the bank was seeded with a riparian buffer native seed mix. LED lighting was used to avoid potential light pollution and disruption to aquatic life.
Diversion of the west bank of Spring Creek around the construction area was a primary consideration during demolition of the existing building and modifications proposed for the existing stream wall. Diversion was accomplished by channelizing the creek around construction area by erecting a temporary portable dam within Spring Creek paralleling the alignment of the new stream bank wall. The suggested portable dam consists of a watertight membrane draped over steel support legs that bear on the stream bed. The ends of the portable dam tie into the stream bank upstream and downstream of the work area, thus diverting Spring Creek flows around the work area.
Hydrologic and hydraulic conditions were assessed and the results indicated that the proposed fill to the existing floodplain will not increase the water surface elevation within the project reach more than one foot.
Water Resources
