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Evaluation of Additional Storage in the Delaware River Basin
April 2023: Final Report
Image of the study cover.

Evaluation of Additional Storage in the Delaware River Basin

In April 2023, the DRBC released a review of future water storage options, Evaluation of Additional Storage in the Delaware River Basin.

This is likely the most comprehensive, Basin-wide evaluation of potential storage options in the Basin in over 40 years. Mott MacDonald was selected to perform the required planning and engineering services to support DRBC staff.

View Report

  •  Evaluation of Additional Storage in the Delaware River Basin (pdf 80 MB; April 2023)

This conceptual, planning-level study developed an inventory of and evaluated the feasibility of additional freshwater storage in the Delaware River Basin to meet the following needs:

  •  Future Water Availability

  •  Climate Adaptation

  •  Drought Management

  •  Flow Management

Study Goals

  •  Inventory and evaluate the feasibility of potential storage projects

  •  Develop a prioritized list to further evaluate if the Commission determines in the future that additional storage is necessary

  •  Help the Commission develop a better understanding of water availability in the Basin and future needs

Key Findings

To date, the Commission has not determined that additional storage is necessary. But, if additional freshwater supply is needed in the future:

  •  There are feasible options available. The report identified 14 projects, 12 repurposed quarries and 2 existing reservoirs with increased storage (see Table 1.4-1 in the report).

  •  Building new storage projects have a large cost environmental impact and were therefore not recommended.

  •  It was difficult to estimate the cost of purchasing/leasing water and how much from an exisiting reservoir (new contracted access to stored water); these projects have no recommendation.

The Delaware River Basin supports the water needs of over 13 million people and is an important water source for public water supply and power generation. Having this planning inventory at the ready in case more freshwater storage is needed helps the DRBC meet its mission of managing and protecting water resources. These types of projects can take decades to plan and implement; this effort provides the DRBC with a head start if needed.

News Release

  •  Delaware River Basin Commission Completes Water Storage Study to Support Resilience Planning (issued April 26, 2023)

Interactive Map: Online GIS Tool

  •  DRBC Storage Study Web Application


DRBC Authority

Section 3.6 of the Delaware River Basin Compact authorizes the Commission to:

Conduct and sponsor research on water resources, their planning, use, conservation, management, development, control and protection, and the capacity, adaptability and best utility of each facility thereof, and collect, compile, correlate, analyze, report and interpret data on water resources and uses in the basin, including without limitation thereto the relation of water to other resources, industrial water technology, ground water movement, relation between water price and water demand, and general hydrological conditions.

Study Initiated in 2021

In April 2021, DRBC announced the beginning of a study to explore the feasibility of additional freshwater storage to meet future water availability, climate adaptation, drought management and flow management needs in the Delaware River Basin.

Mott MacDonald was selected through a competitive process to perform the required planning and engineering services to support DRBC staff.

Funding for this study comes from the Commission's Water Supply Storage Facilities Fund.

Study Objectives

Identify, inventory and evaluate the feasibility of options that could provide the following additional usable storage:

  • A minimum of 1 billion gallons (BG)

  • A minimum of 5 BG

  • A minimum of 10 BG

  • A minimum of 20 BG

The storage volumes can be met by a combination of projects/sources.

Study Approach 

Develop a matrix to use to evaluate storage options. Evaluation metrics to include: feasibility; geographic considerations; regional benefits; temporal considerations; and volume.

  • Storage Projects to be Considered:

    • Construction of new dams/reservoirs

    • Two sub-categories in existing reservoirs:

      • Transfer of control of a certain volume of existing storage in an existing reservoir to the DRBC through purchase or lease

      • Increasing storage in an existing reservoir through raising a dam or inlet

    • Repurposing quarries

    • Repurposing abandoned mines

  • Storage Projects Not to be Considered:

    • F.E. Walter Reservoir (outside study ongoing by the USACE)

    • Tocks Island Reservoir or any other mainstem Delaware River dam
    • Maiden Creek Reservoir (Maiden Creek upstream of Lake Ontelaunee, Berks County)

    • Trexler Reservoir (Jordan Creek, Lehigh County)

    • Hawk Mountain (East Branch Delaware River below Pepacton Reservoir)

    • New York City Delaware Basin Reservoirs (exception: review of the feasibility of the expansion of one or more of the three reservoirs can be considered)

Study Updates

Updates on the study have been provided via the DRBC's Water Management Advisory Committee (WMAC).

Additional Resources

Study RFP & Authorizing Resolution


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