Maryland’s Conowingo Dam was constructed in 1928 and is the most downstream of the four hydroelectric dams located on the lower Susquehanna River. The Susquehanna River basin has a 27,500 square mile (71,225 sq. km.) drainage area (Figure 1) that consists of three states in the United States: Pennsylvania (77% of the area), New York (22%) and Maryland (1%)1 and represents 43% of the land area draining into the Chesapeake Bay, which is the largest of over 100 estuaries in the United States. The Chesapeake Bay receives approximately half of its water volume as freshwater from the 64,000 mile2 (165,759 km2) watershed and the other half as saltwater from the Atlantic Ocean.2 Although all of the dams historically trapped and stored sediment and nutrients in their reservoirs, recent information shows that the Conowingo Dam has reached dynamic equilibrium, meaning sediment behind the dam has built up to the extent that it can no longer trap additional sediment or other pollutants.
The Center for Watershed Protection developed the Conowingo Watershed Implementation Plan (CWIP) to address the additional nutrient and sediment reduction needed to restore the Chesapeake Bay, given this loss of storage capacity. The CWIP is based on the premise that, to successfully reduce the Conowingo nutrient loads, jurisdictions in the Susquehanna River basin must work collectively by pooling resources and reducing implementation costs through targeting pollution reduction practices to the most effective locations.
The United States Environmental Protection Agency (EPA) initiated this effort and continues to administer the cooperative agreements driving the CWIP, which is supported by the Chesapeake Bay Program Principals’ Staff Committee (PSC). The CWIP cooperative agreements are comprised of three activities implemented by third-party grantees, which include:
- Facilitating the development and implementation of the CWIP and associated two-year milestones.
- Developing and proposing a comprehensive CWIP financing strategy and associated implementation plan.
- Tracking, verifying, and reporting the implementation of the CWIP and two-year milestones.
The CWIP was adopted on July 31, 2021, and EPA funded these activities through 2025.
The CWIP provides a strategy to prevent over six million pounds of nitrogen from entering the Chesapeake Bay annually with an estimated cost of $53.3 million per year (Figure 2).
In July 2022, the PSC reached consensus that the Susquehanna jurisdictions can implement the CWIP using a phased approach that extends beyond 2025 to allow time to build the organizational infrastructure needed for implementation. The CWIP Steering Committee — which includes representatives from each Chesapeake Bay jurisdiction (Delaware, the District of Columbia, Maryland, New York, Pennsylvania, Virginia, and West Virginia) and the Chesapeake Bay Commission — meets quarterly to oversee progress and support CWIP implementation.
The implementation milestones developed by the CWIP Steering Committee set specific, measurable goals for the CWIP that include:
- Building capacity.
- Financing and securing funding.
- Fostering innovation.
- Identifying and building partnerships.
- Developing and implementing pilot projects.
- Conducting outreach and engagement.
- Monitoring nutrient reduction targets.
To achieve these goals, the CWIP Steering Committee outlined a uniquely tailored approach for the Conowingo WIP of a two-tiered implementation framework that includes smaller-scale, watershed-specific and broader-scale, state-wide strategies. The best management practices (BMPs) implemented as part of these programs will assist with meeting the numeric load reduction goals for the first phase of implementation that extends through 2025.
The CWIP’s BMP implementation strategy is designed to target landscape-scale restoration strategies using BMPs that integrate into existing agricultural land management practices (such as nutrient application management) and avoid BMPs that remove farmland from production.
Approximately 90% of the nitrogen load reduction in the CWIP is from agricultural BMPs, which include natural filters like wetland restoration and riparian forest buffers, sustainable farm practices like prescribed grazing and conservation tillage, and nutrient reduction practices like nutrient management and manure incorporation.
The CWIP also aims to minimize the cost per pound for nitrogen reduction. To achieve this goal, BMP implementation is targeted to the portions of the Susquehanna River basin that are most effective at delivering nitrogen to the Chesapeake Bay and, therefore, offer the best opportunity to reduce nitrogen loads and improve conditions in the Bay. These areas are referred to as “Most Effective Basins.” Additionally, the CWIP recommends performing evaluations of innovative practices that are not already approved Chesapeake Bay Program BMPs, such as dredging the dam reservoirs, to determine if the pollution reduction benefits from these practices could contribute to CWIP goals.
This BMP implementation strategy is being executed within the context of the Steering Committee’s two-tiered implementation framework that supports smaller watershed and broader state-wide efforts. Smaller-scale outreach has been targeted to specific multi-state watersheds in Most Effective Basins identified in the CWIP, such as the Octoraro watershed that spans portions of Pennsylvania’s Chester and Lancaster Counties into Maryland’s Cecil County. The CWIP implementation team meets with the Octoraro Watershed Association, Octoraro Source Water Collaborative, soil conservation districts from each state and other interested parties in the watershed to form partnerships and discuss projects and funding opportunities. The Susquehanna River Basin Commission (SRBC) developed a “State of the Octoraro Creek Watershed” StoryMap (see Resource) with comprehensive information on water quality and restoration efforts in the watershed. Smaller-scale projects are funded through traditional financing approaches, such as state or federal grants, loans, cost-sharing or other cooperative funding.
Broader, state-wide implementation efforts use a pay-for-performance financing approach in Maryland and Pennsylvania. For both state programs, criteria for awarding pay-for-performance contracts emphasize innovative financing and greatest return on investment in terms of nitrogen reductions. Projects with co-benefits are incentivized to foster new public-private partnerships. Some examples of state-wide funding allocations to achieve CWIP goals are listed below:
- Maryland allocated $25 million for a Verified Nutrient Reductions program that is administered by the SRBC. The first solicitation for projects was issued in 2023 and projects will be awarded in the second quarter of 2024. Maryland’s funds can be used anywhere in the Susquehanna River basin with priority given to projects in Maryland.
- Pennsylvania allocated $22 million to the Clean Water Procurement Program administered by the Pennsylvania Infrastructure Investment Authority for pay for performance projects. The first project solicitation was issued in 2023 with projects awarded in the first quarter of 2024. A second project solicitation was issued in March 2024. Additionally, Pennsylvania awarded the Local Government Impact grant to the Chester County Soil Conservation District for $1.19 million to fund CWIP implementation in the Octoraro watershed.
- New York’s approach to broader state-wide implementation is to fund the Upper Susquehanna Coalition (USC) to administer and manage projects implemented in the Most Effective Basins. New York allocated $1 million over two years that is administered by the USC. The USC is also responsible for verification of BMP performance.
While the implementation strategy for the CWIP targets the Most Effective Basins, it is not site-specific. The strategy recommends certain BMP types based on nutrient removal efficiency and cost-effectiveness and relies upon a cooperative multi-jurisdictional effort. Success will be achieved through close collaboration and coordination across the region, which can be replicated elsewhere by adopting the CWIP’s guiding principles. These include striving for fairness and equity, establishing tracking and accountability with transparency, and implementing efficiently without creating duplicative bureaucracies.
The CWIP development was accelerated by the EPA’s funding of cooperative agreements, which enabled multiple jurisdictions to work together with support from the facilitating agencies minus the burden of going through a procurement process. The EPA cooperative agreements allow the time and resources for the Susquehanna jurisdictions to build new organizational capacity to continue cross-jurisdictional implementation efforts beyond 2025. The collaborative multi-state approach establishes a realistic and achievable framework to be successful in reducing nutrients to and improving the health of the Chesapeake Bay.
References
- Center for Watershed Protection. July 2021 (revised November 2023). Conowingo Watershed Implementation Plan. Prepared as part of U.S. EPA Cooperative Agreement 96366901.
- Chesapeake Bay Commission. June 2020. The Chesapeake Bay and Its Watershed. Retrieved from: https://www.chesbay.us/library/public/documents/Fact-Sheets/Bay-Factoids-FINAL.pdf.
Resource
State of the Octoraro Creek Watershed” StoryMap. Susquehanna River Basin Commission.
https://storymaps.arcgis.com/stories/5c006
f55d58945a5a89b37283bb9a581.
About the Expert
Amanda H. Pollack, PE, is a senior water resources engineer at the Center for Watershed Protection and has over 28 years of engineering experience. She holds a bachelor’s degree in civil engineering from Lehigh University and is a licensed professional engineer in Maryland.
