States join forces for restoration in the Susquehanna watershed

Water doesn’t follow the boundaries of state lines – so successful restoration depends on collaboration across them. 

The Conowingo Watershed Implementation Plan (Conowingo WIP) was put into place to address additional nitrogen, phosphorus and sediment entering the Chesapeake Bay from the Conowingo Dam. While the reservoir behind the dam is designed to trap these pollutants, it is nearing capacity much faster than expected. 

To address this challenge, the Conowingo WIP brings together multiple states and stakeholders through innovative funding mechanisms and partnerships aimed at reducing the amount of pollution flowing into the Bay. Additionally, it recommends financing options to support the installation of best management practices in the Susquehanna River watershed that are intended to reduce the downstream movement of nitrogen, phosphorus, and sediment. 

Several of these strategic investment approaches, including PENNVEST’s Clean Water Procurement Program (CWPP) and the Pay-for-Success Program, rely on pay-for-performance models. Pay-for-performance links payment to successful outcomes. For example, farmers are paid for the amount of nitrogen, phosphorus, and sediment reduced through implemented BMPs. 

In late October, stakeholders working to implement the Conowingo WIP hosted a tour of three project sites in southern Pennsylvania funded through these programs. These projects serve as models of how strategic investment and collaboration can deliver meaningful restoration outcomes. At each site, sediment that had been filling the floodplain for decades was removed, followed by the planting of new native trees and shrubs to create a thriving habitat. All three projects were completed by Resource Environmental Solutions LLC (RES). 

The overarching goal of these projects is to reduce nutrient and sediment loads in local waterways by restoring the floodplain to conditions resembling their pre-European settlement state. Reconnected floodplains provide a safe place for water to go during heavy rain events rather than flowing downtown or flooding roads or homes. As Jon Kasitz, RES Northeast Client Solutions Manager, says, the “goal is to encourage flooding in a controlled way in a controlled place.” 

Our day began with a presentation from Rosetree Consulting, who has been busy engaging with farms across seven counties in Pennsylvania, to encourage them to reduce their use of commercial fertilizer in favor of biological products, such as those that are derived from microbes, plants or other living organisms. This nutrient management approach is cost-effective and proved to be successful. To amplify the impact of this change, Rosetree Consulting also works with farmers to improve the application timing and placement of these products. Funded by Maryland’s Pay-for-Success Progress, the project exceeded its goal by reducing an additional 26,000 pounds of nitrogen over it’s 123,291 pound goal.

Sinking Springs Farm

The first stop on the tour was Sinking Springs Farm, located between busy Interstate-83 and rolling agricultural fields. The property is owned by the York County Sewer Authority and leased to a farmer. 

This site is a testament to the power of using multiple funding sources over time. The most recent phase was funded through the PENNVEST CWPP and built upon three earlier restoration efforts. The first phase was completed in 2019 through Pennsylvania Department of Transportation Municipal Separate Storm Sewer System (MS4) funding. Additional projects followed in 2021 and 2023 to offset new development in York County. 

The site is entirely different now from when RES first started working there. During RES’s initial visit to collect data on the stream, a heavy storm caused stream flows so intense that survey equipment was washed away. There is now a small stream with a healthy floodplain where there was once a six to eight-foot-wide stream with eroded banks. Four- to five-year-old trees stand where construction activity once dominated, and tall grasses and native plants now cover the area. 

TNT Cattle Farm

Next, we head to TNT Cattle Farm project, where restoration began in 2023 and construction finished in October 2025. Using a floodplain restoration approach, the site now features 7.5 acres of restored wetlands.

The RES team had been interested in installing a project at this site several years ago but couldn’t find the right source of funding until the PENNVEST CWPP was released. From the main entrance at the TNT Cattle Farm visitors can see the restored wetland floodplain. Young saplings wrapped in tree tubes are dispersed across the farm, where caterpillars move slowly amid the growing, fresh grass.

Pine Run, which flows through the property, and the broader Muddy Creek watershed were the focus of restoration nearly two decades ago due to chronic flooding. The region directly above the TNT Cattle Farm site is not restored and the eroded banks serve as a visual example of what the stream looked like pre-restoration. Farther upstream, several other restoration projects help with the water flows impacting the TNT Cattle Farm. This project was designed with severe storms in mind, and a wide section of the stream allows water to flood and recede without eroding any banks or damaging the project. If this design is hit with a thousand-year storm, it will flood and go back down to normal levels without issue. This project was entirely funded by the PENNVEST CWPP. 

Green Hill Farm Pollution Reduction Project

Finally, we come to Green Hill Farm, whose restoration project began in 2024 and remains under active construction. This project will create over seven acres of wetlands and restore 3,900 linear feet of stream. Large construction equipment is currently clearing the project site, lowering the floodplain to its historic level. Although this project resembles a typical construction zone, it holds exceptional potential for restoring a historic floodplain–providing habitat, cleaning water and reducing impacts downstream. This project will focus on creating a large-scale wetland and riparian grass buffer on Conowingo Creek and its tributaries. This project was entirely funded by the PENNVEST CWPP. 

Benefits beyond pollution reduction

Although these restoration sites are created for their ability to reduce stormwater, sediment and pollutants, their benefits go far beyond those goals. 

This work is a rapidly evolving field. “We’ve been engineering bridges, and moving water and hydraulics in place as a society for hundreds of years,” says Kasitz. “We know those types of engineering pretty well. Ecosystem, nature based infrastructure engineering and design–it's a pretty new field. So, we are learning on every single project.”

Beyond the nutrient and sediment reductions, these sites create ecological and community benefits, and become critical sources of wildlife habitat. At one RES site in southwestern Pennsylvania, for example, an unknown population of mountain chorus frogs were found.

Landowners and neighbors also share firsthand accounts of how these projects impact them. One landowner told them their garage doesn’t flood anymore when it previously was filled with water at least three times per year. 

These interstate partnerships are cleaning up our waterways, reducing flooding, creating habitat and shaping a more resilient future for the Chesapeake Bay watershed.