Delaware's water, both ground and surface, is one of its most important natural resources. It is essential for meeting the needs of all segments of our society and for maintaining economic growth and agriculture. At this time all water used for public and domestic supply and more than 98% of water used for irrigation south of the Chesapeake and Delaware Canal is ground water. North of the canal, approximately 70% of public water supplies are obtained from four surface-water sources (creeks) and 30% from ground-water resources. Hydrologic investigations are fundamentally important in aiding policy decision makers. As Delaware’s lead earth science agency, the Delaware Geological Survey provides information to inform and educate resource managers and the public to better understand and manage our water resources. The Delaware Geological Survey, by statute, manages and provides liaison for all state-federal projects related to the DGS-USGS Joint-Funded and Partnering Programs.

Groundwater Data

For most of the wells, water levels were measured in monitoring or observation wells by staff members of the DGS and USGS. For a few wells, water levels were measured by employees of consulting firms. Users should be aware that these data records have been checked by DGS staff; however, they are subject to revision. If you have questions or require additional information about the wells or measurements, please contact the DGS through the address at the bottom of this page.

• Data and Graphs of Water Level Summaries for Wells for 20+ years or 100+ observations
• Water Level Summary Table for Index Wells with 20+ years of data
• Spreadsheet table of all wells with 4 or more observations

Water Conditions Summary for Delaware

The Water Conditions Summary is an online monthly summary of water conditions in Delaware. Principal factors in determining water conditions are precipitation, streamflow, and groundwater levels in aquifers. Data from rain gages, stream gages, and observation wells located throughout Delaware have been collected and compiled since the 1960s by the Delaware Geological Survey. These data are displayed as hydrographs and are also available for download. In general, water is abundant in Delaware, but supply is restricted by natural geologic conditions in some areas, by contamination in others, and is dependent on precipitation.

• Water Conditions Summary for Delaware

Surface Water (Stream and Tide Gages)

• Delaware Geological Survey - US Geological Survey Stream and Tide Gaging Program
• Weather, Stream, and Tidal data from the Delaware Environmental Observing System (DEOS)
• Stream Gage Height and Discharge Graphs from the United States Geological Survey (USGS)

Additional Resources

• Delaware Environmental Observing System (DEOS)
• Delaware Environmental Monitoring and Analysis Center (DEMAC)
• Office of the Delaware State Climatologist
• USGS Surface-Water Data for Delaware (stream and tide data)
• USGS Groundwater Data for Delaware
• University of Delaware Water Resources Center
• University of Delaware Water Resources Agency