Aquetong Stream Restoration, Reforestation, and Invasive Species Control

In April 2015, Solebury Township breached the historic mill dam in Aquetong Spring Park to convert the former lake into a natural area with a free-flowing, cold water stream capable of supporting native Brook Trout. After the dam breach, areas of active down-cutting through sediment within the former impoundment were observed along the mainstem and a major tributary of Aquetong Creek.

This resulted in the creation of steep, eroding banks, which increased the sediment load to the sensitive aquatic habitat of Aquetong Creek. Additionally, Solebury Township wanted to control invasive species in Aquetong Spring Park and replant the project area with native species. The Township secured funding to construct riparian buffers, implement streambank stabilization measures, establish trout habitat structures within the mainstem and its tributary, control invasive species, and implement a woodland restoration plan.

Princeton Hydro designed the restoration of the main channel and tributary to reduce channel and bank erosion while supporting Brook Trout habitat. After gathering and reviewing the existing data for the site, Princeton Hydro conducted field investigations to inform and guide the final design including surveying cross sections and performing fluvial geomorphological assessments of the existing channel. Pebble counts were performed, cross sections were analyzed, and existing hydrological data was reviewed to inform the design. Simultaneously, an invasive species control and woodland restoration plan was developed for the park.

Data collected from the site was used to develop a geomorphically-appropriate, dynamically-stable design. The proposed channel design included excavation of impounded sediment to create stable channel dimensions, the addition of gravel, cobble, and boulder substrate where original/existing channel substrates were absent or insufficient, and the installation of large wood features to create aquatic habitat and enhance stability of channel bed and banks. The banks and riparian corridor were vegetated with native seed, shrubs and trees to ultimately create a wooded, shaded riparian buffer. The design ultimately stabilized the streambanks with features that double as trout habitat and replanted the surrounding park with native vegetation.

Princeton Hydro also provided stormwater design support for adjacent areas in Aquetong Spring Park including multiple stormwater connections to the main tributary. After completion, Princeton Hydro provided bid assistance, developed a probable cost, drafted technical specifications, and produced a bid package to assist the client in bringing the project to construction. Princeton Hydro continues to work with the Township to monitor the site.