NTM developed a channel restoration design for the Park Hills Drainageway in Ferguson Township, Centre County. The primary objective of the Park Hills Drainageway Improvements project was to create a stable channel contained within open space lands owned by the Township. The Park Hills Drainageway is an actively eroding, incised, ephemeral channel. The erosion was a result of uncontrolled runoff from suburban residential development constructed in the 1960s and 1970s. The drainageway was also used as a utility corridor for sanitary sewer, power, and communication utilities serving adjacent residential lots.
Primary project challenges include minimizing impacts to mature trees, adjacent residential properties and the existing floodplain; site construction access; utility coordination and relocation, and waterway permitting.
An innovative riffle/step-pool design, modeled after a regenerative stormwater conveyance (RSC) design approach, was used for channel restoration to better manage flow energy through the corridor. In addition to providing a stable channel, the riffle/step-pool approach also produces a natural visual appearance which complements the woodland and meadow environment the drainageway flows through. The design also provides water quality treatment, helping the Township meet pollution reduction requirements under their stormwater discharge permit (MS4 Permit). As the design features remain in place, vegetation will reestablish and a permanent, sustainable drainageway will thrive in the backyards of many homeowners along the approximately 2,500-foot project reach.