Monitoring

Our Territory

Gunpowder RIVERKEEPER® is responsible for protecting over 800mi2 of land, including the Gunpowder, Bush, Bird, and Middle River watersheds.

With the help of our staff and volunteers, Gunpowder RIVERKEEPER® monitors tidal and non-tidal sites along the Gunpowder and Bush River basins weekly throughout the summer. The economic, biological and recreational importance of the River raises a pressing need for independent and comprehensive baseline environmental monitoring/mapping of the river and its watershed. This data will be visualized through GIS mapping and shared with regulatory agencies

You can find updated monitoring results here on our website and across all our social media platforms.

Bacterial Monitoring

Monitoring Program

Gunpowder RIVERKEEPER® monitors both tidal and non-tidal waterways across its managed territory to help safeguard public health and environmental integrity. Each summer, from Memorial Day through Labor Day, we conduct weekly E. coli testing at strategically selected sites popular for swimming, paddling, and fishing.

Gunpowder Riverkeeper employees/volunteers taking an E.coli sample at Gunpowder Falls in Monkton, MD

Recent Monitoring Results

Monitoring Sites

Our goal is to provide the public with transparent, science-based information so they can make informed decisions about how and where to safely enjoy local waterways. As our program grows, we aim to expand this network throughout the watershed.

What We Monitor For

Gunpowder RIVERKEEPER®’s weekly monitoring (Memorial Day-Labor Day) provides a snapshot of E. coli levels at the time a sample is taken. These efforts help ensure the safety of those swimming and fishing the gunpowder river as higher levels of E.coli found within the water can cause potential health risks.

This data reflects single-grab samples which are susceptible to variance, meaning E.coli levels may change rapidly depending on various factors such as rainfall.. As always, please follow Maryland Department of the Environment (MDE) guidance to avoid swimming within 48 hours of a 1″ rainfall event, and use caution when recreating in natural waters.

What We DO NOT Monitor For

  • Harmful algal blooms (e.g., cyanobacteria)
  • Vibrio
  • Pfiesteria
  • Other waterborne viruses or parasites

Tidal Monitoring

Gunpowder Riverkeeper employees out on the ‘Skiff’ taking samples of tidal sites

Monitoring Sites

Chesapeake Water Watch Volunteer Program

Gunpowder RIVERKEEPER® is proud to partner with the Chesapeake Water Watch (CWW), a NASA‑funded, community science initiative led by the Smithsonian Environmental Research Center (SERC) and the City University of New York (CCNY). The Gunpowder Riverkeepers staff provide data from samples taken to aid CWW’s goal of helping to “ground truth” NASA and European satellite imagery of the Chesapeake Bay by collecting in‑situ water quality data in under‑monitored tidal tributaries.

Analyzing Samples

After returning from the field (or water), our team processes the samples at Marshy Point Nature Center. We use a handheld fluorometer to measure chlorophyll-a and colored dissolved organic matter (CDOM), which help indicate algae levels and water clarity. These results, along with our HydroColor app data, are submitted to the Chesapeake Water Watch project to support satellite calibration and long-term estuary health tracking.

Meet Our Monitoring Team

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