At a Glance

Stream and wetland restoration add ecological value to a public preserve located on a historic site.

Project Description

Located less than 20 miles north of Philadelphia, the Piszek Preserve spans 36 acres of woodlands, wetlands, and meadows adjacent to a private, 18th century estate that once served as winter quarters for George Washington. The majority of the Preserve’s land was donated to the Wissahickon Valley Watershed Association (WVWA) by the Piszek family, with support from the Montgomery Lands Trust. In addition to its woodlands, wetlands, and meadows, the Preserve includes two ponds and a narrow canal which are fed by Sandy Run, a tributary to Wissahickon Creek that flows through the property. A historic mill dam is located along a portion of Sandy Run. Over time, the ponds and canal had begun to dry out, offering little in terms of beauty and ecological function. The site had also become dominated by invasive Japanese knotweed (Fallopia japonica).

When PennDOT built a temporary bridge over Sandy Run on Preserve property to facilitate a nearby bridge replacement project, WVWA turned to Biohabitats for help in restoring the area of the stream impacted by the temporary bridge and creating a plan to improve the site’s overall ecological function.

Biohabitats led two restoration projects at the Preserve. First, Biohabitats developed and led the implementation of a design to stabilize the banks and improve the ecological function of the impacted reach of stream. The design included revegetation of the riparian zone with native plants. Second, Biohabitats prepared permit-ready plans to transform the stagnant ponds into emergent wetlands and convert the narrow canal to a wetland swale. Informed by a site assessment that included survey, wetland delineation, an evaluation of invasive species, and an examination of site hydrology, the design approach focused on maintaining the property’s historic look while adding ecological function.



Chesapeake/Delaware Bays

Physiographic Province




Expertise Areas

Ecological Restoration


Wissahickon Valley Watershed Association


Upper Dublin & Springfield Townships, Pennsylvania, United States

Project Team
  • AEG
  • May Horticulture