One of the main responsibilities of DRBC's Water Resource Planning Branch is long-term water supply planning for the basin.

In order to project long-term, we need to have an understanding of how water is currently being used in the basin, as well as explore historical data.

In 2021, the DRBC published a report assessing 30 years of water withdrawals and consumptive use in the Delaware River Basin, with projections through the year 2060.

• Water Withdrawal and Consumptive Use Estimates for the Delaware River Basin (1990-2017) With Projections Through 2060 (October 2021)

Delaware River Basin Water Use

• An estimated 14.2 million people rely on water from the Basin for their daily water needs (2020 data).
  
  
  • Approximately 8.6 million people live in the Basin. 
    
    
  • The volume of exports to New York City and northeastern New Jersey is sufficient to supply water to an additional 5.5 million people.
    
    
• Total ground and surface water withdrawals from the Basin: 6,390 mgd (~6.4 Billion gallons per day; 2020 data)
  
  
• Total Consumptive Use (consumptive use is the portion of water withdrawn from a watershed that is not immediately returned): 847 mgd (2020 data)
  
  
  • Major Exports from the Basin: 594 mgd (out-of-basin water diversions)
    
    
  • Consumptive Use in the Basin: 263 mgd (e.g., from public water supply, thermoelectric and irrigation)
    
    
• Approximately 95% of all water used in the Basin is obtained from surface waters.

Major Water Use Sectors

Three dominant use sectors account for over 68% of total water withdrawals in the DRB:

• Power Generation (aka Thermoelectric, 49%)
  
  
• Public Water Supply (PWS, 12%)
  
  
• Industrial use (7%)

Some Key Findings from the 2021 Water Use/Projection Report

• Peak water withdrawal from the Delaware River Basin has likely already occurred (in 2005 and 2006 it was estimated to be approximately 9.917 billion gallons per day).
  
  
• In addition to the three major water use sectors (power, public water supply and industry) tracked by the DRBC, irrigation is also a key sector that is strongly correlated with climatic variables.
  
  
  • Power (Thermoelectric): Water withdrawals have decreased and are projected to continue to decrease. However, consumptive use is expected to remain constant.
    
    
  • Public Water Supply: Water withdrawals have decreased and are projected to continue to decrease despite an increasing population.
    
    
  • Industry: Water withdrawals and consumptive use have decreased and are expected to remain constant.
    
    
  • Irrigation: Comprised of multiple uses; the primary is agricultural irrigation. Withdrawals and consumptive use are projected to increase in the future.

[mgd = millions gallons per day]

Water withdrawals are tracked throughout the basin to identify key water-using sectors and trends in use.

This figure shows the basin-wide picture of water withdrawals, exports and consumptive use, by sector, based on 2020 calendar year water use data; the data shown represent daily average withdrawals.

Groundwater Withdrawals in the DRB

While groundwater withdrawals only amount to about 5% of all water withdrawn from the DRB daily, it is still important to track. The majority of that 5% is for drinking water supply (public and private wells).

DRBC Publication

• Estimated Groundwater Availability in the Delaware River Basin 2020 - 2060 (pdf; December 2022)

Key Takeaway: Groundwater resources are being used at sustainable rates in the Delaware River Basin.

The below graphic shows net groundwater withdrawals (1990-2020) and projections (to 2060) for the entire Delaware River Basin, broken down by water use sector.

Special Groundwater Management Areas in the DRB

Two areas of the DRB are included in special management programs to mitigate historical groundwater supply issues and prevent future stress: the Southeastern Pennsylvania Groundwater Protected Area (maged by the DRBC on behalf of Pa.) and N.J. Critical Area 32 (managed by N.J.). These programs have been successful in protecting the resource, through stricter control and regulation of groundwater withdrawals, water conservation programs and an overall increase in surface water diversions to supplement or reduce groundwater withdrawals.

• Southeastern Pennsylvania Groundwater Protected Area (SEPA-GWPA) (managed by the DRBC on behalf of Pa.)
  
  
• Critical Area #2 in southwestern New Jersey (managed by N.J.)

The below graphic shows net groundwater withdrawals (1990-2020) and projections (to 2060) for the SEPA-GWPA, broken down by sector.

Water Resources Program

• DRBC's 2023 Water Resources Program (pdf)

Water Use/Withdrawal Info

• 2023 Technical Report for the Delaware Estuary and Basin: DRBC-Authored Chapter 3 - Water Quantity (pdf)
  
  
• CY2020 Water Use Updates (pdf; presentation given at the June 16, 2022, WMAC Meeting)
  
  
• Water Withdrawal and Consumptive Use Estimates for the Delaware River Basin (1990-2017) With Projections Through 2060 (publication issued October 2021)
  
  
• State of the Delaware River Basin 2019
  
  
• Watersheds and Water Use (pdf; presentation given at the Water Resources Association of the Delaware River Basin Fall Technical Symposium, Nov. 2019)
  
  
• DRBC Water Demand Management: Benefits of Promoting Best Practices (pdf; presentation given at the AWRA National Conference, November 2018)
  
  
• Consumptive Use Replacement Program for Power Facilities in the Delaware River Basin (pdf; presentation given at the AWRA National Conference, November 2018) 
  
  
• Map of Surface Water Withdrawals in the Delaware River Basin (pdf)
  
  
• U.S. Geological Survey (USGS) Water Budgets for Selected Watersheds in the Delaware River Basin, Eastern Pennsylvania and Western New Jersey - This 2005 report was written in cooperation with the Delaware River Basin Commission.

Groundwater Info

• Estimated Groundwater Availability in the Delaware River Basin 2020 - 2060 (pdf; publication issued December 2022)
  
  
• Is Groundwater Being Used Sustainably in the Delaware River Basin? (pdf; presentation given at the Nov. 2022 American Water Resources Association National Conference)
  
  
• Estimated Groundwater Availability in the Delaware River Basin (pdf; presentation given at the June 16, 2022, WMAC Meeting)
  
  
• Estimated Groundwater Availability in the Delaware River Basin (pdf; presentation given at the February 17, 2022, WMAC Meeting)
  
  
• Staff developed R scripts to view current levels in certain monitoring wells in the Southeast Pennsylvania Groundwater Protected Area, which can be viewed at https://drbc.net/Sky/sepagwpa.htm.
  
  
• Staff also developed R scripts to view current levels in certain monitoring wells in New Jersey Critical Area 2 can be viewed at https://drbc.net/Sky/nj2.htm.
  
  
• Map of Basinwide Groundwater Withdrawals (jpg; 2016)

DRBC

• DRBC Authorities, Regulations, and Guidance
  
  
• DRBC Water Conservation Policies
  
  
• DRBC Water Audit Program
  

Delaware

• Water Supply
  
  
• Water Allocation

New Jersey

• New Jersey Dept. of Environmental Protection - Division of Water Supply and Geoscience
  
  
• New Jersey Water Supply Plan

New York

• Division of Water
  
  
• Water Withdrawal Permits & Reporting

Pennsylvania

• Pa. Dept. of Environmental Protection - Division of Water Planning and Conservation
  
  
• Pennsylvania State Water Plan