Four Mile Run Hillside Restoration


Pittsburgh Parks Conservancy


Pittsburgh, PA

CEC Services

  • Geotechnical Engineering
  • Landslide Assessment/Remediation
  • Predevelopment Site Investigations
  • Slope Stability/Retaining Structure Design
  • Stormwater Management/BMP Design
  • Aquatic & Terrestrial Habitat Surveys
  • Ecological Risk Assessment & Land Restoration
  • Ecosystem Restoration
  • Invasive Plant Management
  • Soil Science and Phytoremediation
  • Low Impact Development Design
  • LiDAR Surveys—Short- and Long-Range
  • Topographic Surveys
  • Unmanned Aerial Services
  • GPS/GIS Services
  • Web & Mobile Application Development

Owner Objective

The Pittsburgh Parks Conservancy (PPC) is a Pittsburgh nonprofit conservation organization dedicated to support of parks within the city, particularly the five major parks. The PPC works with other nonprofit foundations and the City of Pittsburgh to develop and implement aspirational projects in the parks.

The PPC has long been involved with the 456-acre Schenley Park. The PPC commissioned a study completed in 2017 to identify opportunities to match solutions to local stormwater and combined sewer overflow and flooding concerns with park maintenance problems. The PPC stormwater study helped spark a comprehensive Pittsburgh Sewer and Water Authority (PWSA) project, led by CEC, to separate stormwater and to “daylight” Four Mile Run, a stream that was buried in the combined sewer system decades ago. Invasive plants are replacing native species in the park, and excessive deer populations have decimated the understory of the park and prevented forest regeneration and sustainability. Slopes are very steep, stormwater is flashy, and, as a result, soil erosion and landslides are common. PPC hired CEC to evaluate the challenges of soil erosion, landslides, and invasive plants that represent threats to the physical and biological health of the park and to the viability of daylighting Four Mile Run.

CEC Approach

CEC used a combination of high-technology tools and experienced field staff to address concerns of PPC erosion, landslides, forest stability, and invasive plants. CEC used ultra-high-resolution LiDAR scanning from drones and GIS to identify areas of past and recent landslides, and then geotechnical engineering staff followed up on foot to confirm conditions. CEC ecologists surveyed native, non-native, and invasive plant communities throughout the park and developed prioritized vegetation management and restoration plans that dovetail with PWSA stream daylighting plans. In an area of the park where a tree nursery was contemplated, CEC ecologists, soil science, and engineering staff conducted an extensive evaluation of soil properties for stormwater management and nursery development and developed schematic plans for beneficial use of stormwater for irrigation of the nursery, which was built and planted in the fall of 2019.

CEC is supporting the integration of PWSA stormwater and Combined Sewage Overflow (CSO) management plans with the PPC’s plans to improve and sustain Schenley Park, to include daylighting of stormwater to recreate the Four Mile Run stream, and to begin the restoration of sustainable native plant communities that provide beauty, connection with nature, habitat, and stable soils in the park.