Design, Construction and Monitoring of the Fire Pond Mitigation Site: Converting a Pond to a Stream and Wetland Complex
Mike Miller
McCormick Taylor, Inc.
Harrisburg, PA
PennDOT District 2 initiated the design and construction of a stream and wetland complex at the Fire Pond site to provide mitigation credits for Section B06 of the SR 322 Potters Mills Gap Transportation Project. The Fire Pond mitigation site is located on Pennsylvania Department of Conservation and Natural Resources (DCNR) property at the Mira Lloyd Doc Resource Conservation Center in Centre County, PA. The pond was no longer needed by DCNR to provide a water source in case of fire due to the large amount of wood stored on site and was, therefore, available for conversion/mitigation.
Design of the Fire Pond mitigation site consisted of removing the dam/embankment and converting an approximately 1-acre pond to 600 linear feet of channel/floodplain and 0.8 acres of wetland. The project stream is an unnamed tributary to Potter Run, which is classified as a Class “A” Wild Trout Stream by the PA Fish and Boat Commission, indicating presence of naturally produced trout that support a rewarding sport fishery. The stream design included riffle habitat structures (with embedded logs), floodplain benches and minimized rock on the banks. The wetland elevation was set approximately five feet higher than the stream/floodplain to maintain wetlands located along the fringe of the pond footprint. In addition to mitigation, this project was important to the resources agencies as it removed a source of elevated water temperature within the Potter Run watershed.
Construction of the Fire Pond was unique due the pond setting and the proposed differences in elevation between the stream/floodplain and wetland. Construction required draining the pond, removing the dam/embankment, multiple pump locations for maintenance of streamflow, removing unconsolidated/mucky sediment from the pond bottom, furnishing and compacting large amounts of fill to construct proposed grade, frequent testing of material and compaction, and flexibility to work within the project setting. Construction of the Fire Pond mitigation site was completed between January and March of 2019 and post-construction monitoring was initiated in fall of 2019.
This presentation focuses on providing background on the proposed design, construction techniques due to the unique setting, and initial monitoring results.
About Mike Miller
Coming Soon