Chesapeake Bay National Estuarine Research Reserve

Monitoring Groundwater

Monitoring groundwater at Jug Bay. Photo credit: J. Campbell Under predicted climate change conditions, particularly the increasing of sea level, it is important to understand the potential impacts this change may have in the hydrology of marsh communities. Of great interest is to determine the impact of sea level rise in groundwater, including groundwater level and salinity intrusion. Monitoring for salinity intrusion is especially important at Jug Bay and Otter Point Creek. These Reserve components are composed of tidal freshwater marshes (wetlands where salinity is almost zero) and small increases in the amount of salt found in groundwater may cause significant changes in some of the plants found in this particular environment.

In 2012, CBNERR-MD started an initial effort to monitor groundwater at Jug Bay. To do this, three water wells were established at three different marsh areas (areas also used to monitor marsh plants) and equipped with automated loggers that record every 15 minutes information on groundwater level, temperature, and salinity. Data from these loggers is retrieved every four to six months and analyzed for any local trends.

The main objectives of this project are to:

  1. Retrieving groundwater data from an automated logger. Photo credit: J. Campbell  Evaluate changes in groundwater over time particularly as a result of sea level rise and to determine how these changes may relate to changes in the marsh plant community.
  2. Determine natural groundwater changes in space and time in tidal freshwater systems.

As a next step, our program would like to expand the monitoring of groundwater to other areas of the Jug Bay marsh, and to the other Reserve components: Otter Point Creek and Monie Bay.

How to Get Involved:

If you are interested in helping with our groundwater monitoring effort, please contact the Research Coordinator Patricia Delgado at ( No experience is required. Sampling involves walking in the marsh, the operation of equipment used to monitor groundwater, downloading of data, and note-taking. In return, you would have the opportunity to learn about groundwater monitoring while enjoying the wonders of Jug Bay tidal freshwater marshes.

Available Information:

If you are interested in our groundwater data please contact Stewardship Coordinator, Chris Snow (


Sampling marsh vegetation at Jug Bay (Credit: L. Carroll)

Our Science

Explore and learn about the interesting research and long-term monitoring projects we are conducting at Otter Point Creek (Bush River), Jug Bay (Patuxent River), and Monie Bay (eastern shore). Our projects range from water quality monitoring to marsh plants to monitoring secretive marsh birds and fish.​​​​​


Links to Our Data

Our Data

We invite you to use our data to support research, modeling, management, and/or education goals. Our data could serve as baseline information to start a new research project, to look for interesting trends, to support modeling efforts, or to complement a project already in progress. We hope our data can help you to make a difference!

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