Maryland-Delaware-D.C. Water Science Center


The water resources of Maryland, Delaware, and the District of Columbia consist of numerous streams, springs, lakes, and aquifer systems. Streamflow, groundwater levels, and water-quality data are collected at numerous locations, and water-use data are collected throughout the area in cooperation with other federal, state and local agencies, universities, and research centers...

Chesapeake Bay Activities

Chesapeake Bay Activities

The USGS has the critical role to provide scientific information for the improved understanding and management of the Bay ecosystem. The USGS works with Federal, State, and academic science partners to provide research, assessment, and monitoring.

USGS Chesapeake Bay

Local Water Conditions

Local Water Conditions

Explore real-time streamflow, groundwater, and water-quality conditions and access data for MD, DE, and DC with our new interactive map application. This application offers data displays on multiple device platforms with various basemap options.

Local Water Conditions


Featured below are some popular features on the MD-DE-DC Water Science site. To better navigate our pages, please use the vertical header listing to the left side of this window.

NEWS! Monthly Water Conditions

Water Conditions for Maryland

Water Conditions for Delaware

Water Conditions for Washington, DC

Recent Publications from MD-DE-DC

USGS Water Science Center Seminars & Talks

Maryland Storm-Tide Sensor Network

Jump into NWIS WEB!


Date published: September 16, 2018

Hurricane Florence Water Footprint Data Visualization

To learn more about USGS’ role providing science to decision makers before, during and after #Florence, visit the #USGS Hurricane Florence page at

Date published: September 15, 2018

USGS deploying more gauges for Florence, preparing to measure flooding

To learn more about USGS’ role providing science to decision makers before, during and after #Florence, visit the #USGS Hurricane Florence page at

Date published: September 11, 2018

USGS Scientists Prepare for Storms in Three Seas

Field work completed for powerful Hurricane Florence, while experts watch Isaac and Olivia

Editor's note: This story was originally published on Tuesday, Sept. 11 and was updated at noon on Wednesday, Sept. 12.

To learn more about USGS’ role providing science to decision makers before, during and after Hurricane Florence, visit the USGS Hurricane Florence page at


Publication Thumbnail
Year Published: 2019

Changes in event‐based streamflow magnitude and timing after suburban development with infiltration‐based stormwater management

Green stormwater infrastructure implementation in urban watersheds has outpaced our understanding of practice effectiveness on streamflow response to precipitation events. Long‐term monitoring of experimental urban watersheds in Clarksburg, Maryland, USA, provided an opportunity to examine changes in event‐based streamflow metrics in two treatment...

Hopkins, Kristina G.; Bhaskar, Aditi S.; Woznicki, Sean; Fanelli, Rosemary

Publication Thumbnail
Year Published: 2019

Small ponds in headwater catchments are a dominant influence on regional nutrient and sediment budgets

Small ponds—farm ponds, detention ponds, or impoundments below 0.01 km2—serve important human needs throughout most large river basins. Yet the role of small ponds in regional nutrient and sediment budgets is essentially unknown, currently making it impossible to evaluate their management potential to achieve water quality objectives. Here we used...

Schmadel, Noah; Harvey, Judson; Schwarz, Gregory; Alexander, Richard; Gomez-Velez, Jesus D.; Scott, Durelle; Ator, Scott

Publication Thumbnail
Year Published: 2019

Estimation of base flow by optimal hydrograph separation for the conterminous United States and implications for national-extent hydrologic models

Optimal hydrograph separation (OHS) uses a two-parameter recursive digital filter that applies specific conductance mass-balance constraints to estimate the base flow contribution to total streamflow at stream gages where discharge and specific conductance are measured. OHS was applied to U.S. Geological Survey (USGS) stream gages across the...

Foks, Sydney; Raffensperger, Jeff P.; Penn, Colin A.; Driscoll, Jessica M.