Partnering with Wildlands Conservancy to Remove Dams in the Lehigh River Valley

According to American Rivers, “more than 90,000 dams in the country are no longer serving the purpose that they were built to provide decades or centuries ago.” As these dams age and decay, they can become public safety hazards, presenting a failure risk and flooding danger. Dams can also be environmental hazards, blocking the movement of fish and other aquatic species, inundating river habitat, impairing water quality, and altering the flow necessary to sustain river life.

Removing nonfunctional, outdated dams has myriad ecological benefits. Dam removal can improve water quality, restore a river back to its natural flowing state, reconnect river habitats that benefit fish and wildlife, and significantly increase biodiversity for the surrounding watershed.

Removing Dams in Lehigh Valley

For over a decade, Princeton Hydro has partnered with Wildlands Conservancy to remove dams in the Lehigh River Valley. Wildlands Conservancy, a nonprofit land trust in eastern Pennsylvania, works to restore degraded stream and wildlife habitat with a primary focus on Lehigh Valley and the Lehigh River watershed, which is a 1,345 square mile drainage area that eventually flows into the Delaware River.

Wildlands Conservancy contracted Princeton Hydro to design and permit the removal of two dams on the Little Lehigh Creek. Although it is referred to as the “Little Lehigh,” the 24-mile creek is the largest tributary of the Lehigh River. The dam removals restored the natural stream system, which hadn’t flowed freely in over a century.

Princeton Hydro also worked with Wildlands Conservancy to remove several barriers and three consecutive low-head dams on Jordan Creek, a tributary of the Little Lehigh Creek. Jordan Creek arises from a natural spring on Blue Mountain, and eventually joins the Little Lehigh in Allentown before flowing into the Lehigh River. It drains an area of 75.8 square miles.

As part of the dam and barrier removal projects, Princeton Hydro:

– Conducted dam and site investigations;
– Oversaw structural, topographic, and bathymetric field surveys and base mapping;
– Performed geomorphic assessments and sediment characterization to predict river response to dam removals and develop appropriate sediment management plans;
– Performed hydrologic and hydraulic analysis to predict changes in river hydraulics;
– Evaluated and addressed technical issues unique to each barrier;
– Coordinated with regulatory agencies and entities;
– Participated in community informational meetings;
– Developed engineering design plans, documents, and permit application submissions;
– Developed construction cost estimates for implementing the removal of the dams and streambank stabilization; and
– Performed construction oversight during implementation.

Collectively, these dam and barrier removal projects on the Little Lehigh and Jordan Creek reconnected 15+ miles of river; restored fish passage; improved aquatic connectivity, fisheries, and benthic macroinvertebrate and wildlife habitats; reduced nonpoint source stormwater pollution; improved water quality; addressed vulnerable infrastructure; enhanced climate resiliency; and stabilized and restored the creeks’ channels and banks.

Upcoming Conservation Efforts

Building upon the successes of the Little Lehigh and Jordan Creek barrier removals, Princeton Hydro is again partnering with Wildlands Conservancy to remove three consecutive dams on Bushkill Creek in Easton, PA. The dam removal projects, which are slated for 2023, are part of a large-scale effort, involving a significant number of community and municipal partners, focused on restoring Bushkill Creek and the surrounding watershed.

The Bushkill Creek is a 22-mile long limestone stream that is designated as a “high quality, cold-water fishery.” It supports healthy populations of trout, and is treasured by anglers and the surrounding community as an important resource in an urban environment, spanning several boroughs and townships, eventually flowing into the Delaware River at Easton.

Environmental protection and restoration is a key goal of removing the dams. Removing these barriers will allow important migratory fish species to reach their spawning grounds once again, which has numerous and far-reaching ecological benefits. The project work also includes stabilizing the streambank, planting, and expanding riparian buffers, planting native trees and shrubs to filter runoff, and installing in-stream structures to restore fish habitat.

Stay tuned for more updates in 2023!

Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of over 60 of small and large dams in the Northeast. To learn more about our fish passage and dam removal engineering services, click here. To learn more about Wildlands Conservancy, click here.

• Dam and Barrier
• Engineering
• Natural Resource Management
• Stream Restoration