Case Studies
Collaborative Approaches to Water Management in a Changing Climate in the Delaware River Basin
This case study highlights the role of the Delaware River Basin Commission (DRBC) in establishing dialogue and building consensus across states and municipalities, including New York City and Philadelphia, that rely on the Delaware River for water. In particular, the case study investigates how a climate change advisory committee is guiding the development of new technical knowledge while grappling with potential regional changes in water availability and quality.
The Delaware River Basin extends through parts of New York State, Pennsylvania, New Jersey, and Delaware. Basin water withdrawals exceeded 5700 million gallons per day in 2018, providing essential cooling water to power plants, irrigation water to farms, non-potable water to industry, and drinking water to over 15 million people.1 About one-fifth of the upper watershed lies within New York State in the Catskill Mountains. This includes three major water supply reservoirs for New York City (Cannonsville, Pepacton, and Neversink). Near the outlet of the Delaware River, the City of Philadelphia draws in drinking water for its residents. A 1954 Supreme Court decree established a basis for water sharing between the states. In the 1960s, a legislative agreement—the Delaware River Basin Compact—created the DRBC to address water risks such as droughts, low flows, flooding, and pollution.2
Highlights
- Legislative agreements between state and federal governments established the DRBC as a multi-jurisdictional entity to coordinate water management for users and stakeholders, including Philadelphia and New York City.
- In recognition of the potentially substantial impacts of climate change on the basin’s water resources, the DRBC formed the Advisory Committee on Climate Change (ACCC) in 2019.
- The ACCC provides guidance and feedback on the DRBC’s modeling, monitoring, and research activities for the Delaware River system. It helps DRBC technical staff predict changes in water quality and availability. This approach can serve as a model for making similar decisions on other water bodies.
For the last 60 years, the DRBC has helped improve water quality and prevent interstate conflicts over water access. The success of the DRBC is partly due to the technical information and knowledge it provides, which facilitates dialogue among federal, state, and municipal entities. To provide focused guidance and discussion, the DRBC relies on technical advisory committees. Longstanding advisory committee topics have included toxics, water quality, and flooding. The DRBC formed the Advisory Committee on Climate Change (ACCC) in 2019. The ACCC consists of 18 members who represent Compact parties and additional members from academic and research institutions, environmental and watershed organizations, businesses and industry, and water and wastewater utilities. The purpose of the ACCC is to provide scientific information and recommendations for identifying and prioritizing climate-related threats and vulnerabilities; planning scenarios; and developing hazard mitigation, adaptation, and resilience strategies.3 For example, ACCC members continue to discuss how to properly portray regional climate risks when downscaling climate model output to make it represent a much smaller region. These and similar discussions within the ACCC can uncover analytical weaknesses and improve predictive science.
Recent climate work by the DRBC includes hosting the 2023 ACCC Climate Change Forum (part of the Partnership for the Delaware Estuary biennial Science Summit), identifying funding opportunities to advance equitable climate resilience solutions, working directly with communities to develop hazard mitigation plans, and improving scientific understanding of flooding and water availability within the basin.
The DRBC’s Climate Work Plan includes the development of sustainable water availability planning studies, an interactive regional resilience tool, and modeling tools. On behalf of DRBC, the Northeast Regional Climate Center at Cornell University developed an interactive tool to project extreme precipitation to support regional resilience and reduce flood loss. The salinity model developed by the DRBC evaluates the effects of salinity and sea level rise on the Delaware River basin, informing management of surface water flow and reservoirs.4
As part of the overall Climate Work Plan, the DRBC is developing a Climate Action Plan with input from the ACCC. The Climate Action Plan highlights the work the DRBC intends to do in the areas of flow management/drought, flood loss, water quality, project reviews, equity and environmental justice, and climate trends and metrics. These activities include reviews of and potential updates to policies, regulations, and codes based on climate information and data for the Delaware River basin.
The ongoing work by the DRBC and the ACCC is a valuable example for other water management decision-making. Small and large water entities in other locales could attempt to pursue similar conversations with government officials and academics as well as prepare to address future climate challenges.
For More Information
References
1. McCabe, G. J., & Wolock, D. M. (2020). Hydro‐climatic drought in the Delaware River Basin. Journal of the American Water Resources Association, 56(6), 981–994. https://doi.org/10.1111/1752-1688.12875
2. Delaware River Basin Commission. (1961). Delaware River Basin Compact. https://www.nj.gov/drbc/library/documents/compact.pdf
3. Delaware River Basin Commission. (n.d.). Advisory Committee on Climate Change (ACCC). Delaware River Basin Commission. Retrieved January 23, 2024, from https://nj.gov/drbc/about/advisory/ACCC_index.html
4. Kavanagh, K. B. (2023, December 20). DRBC Climate Water Resources Program and Work Plans. Advisory Committee on Climate Change. https://www.nj.gov/drbc/library/documents/ACCC/122023/Kavanagh_DRBCclimate-work.pdf