Baseflow Nitrogen Concentrations in Hunting Creek Tributaries, 2021-2025: Mostly Good News!

Since 2021, the Friends of Hunting Creek (FOHC) have been the self-proclaimed eyes, ears, and advocates for Calvert County’s largest watershed. Their longest-running method of monitoring is a simple yet effective once-a-year program known as the Water Quality Blitz. Each spring, the FOHC takes to the non-tidal, upper tributary streams of the Hunting Creek watershed, collecting water samples for nitrogen (NO23) analysis. By timing the Blitz with early spring, pre-leafout conditions, and executing the sampling on a day when no significant rainfall has diluted stream contents, the FOHC can accurately estimate baseflow nitrogen concentrations in the watershed. This allows for the identification of nitrogen hotspots in the watershed, and, collected over time, this data can give insights into the changing conditions of the streams. 

With five years of nitrogen data now in hand, the FOHC is beginning to piece together the story that the streams are telling, while acknowledging that five years is still insufficient for drawing definitive conclusions about long-term trends. However, they have begun to notice patterns in the results, namely the locations of elevated nitrogen concentrations and how the surrounding land use likely plays a role. 

One site located in Little Lyons Creek has exhibited elevated NO23 concentrations for all five years of testing, likely reflecting the surrounding agricultural land use, where additives like fertilizers can leach into the groundwater. Other sites, located in Fox Point Creek and Quail Ridge Run, have shown on-and-off elevated NO23 conditions, presumably linked to the influence of nearby development and suburban runoff. The land use/land cover maps for these three locations are shown on the maps to the right. Thankfully, these findings aren’t an immediate cause for alarm; however, they do help paint a clearer picture of how different streams respond to the land use around them.

The good news? Across all five years of sampling, none of the sample sites showed nitrogen levels high enough to earn a POOR categorization for ecological health. Most sites received a GOOD rating from 2021-2025, indicating that baseflow nitrogen concentrations remain low and overall healthy. In fact, the mean nitrogen

concentration for each year of sampling was below 0.7 mg/l, or GOOD. Even more good news, a recent, short-term trend analysis of five years of data found that four sites in the

watershed showed a statistically significant decline in nitrogen levels. HC3 in Little Lyons Creek showed the largest decrease, but the baseflow nitrogen level there in 2025 was still in the FAIR condition range. These trends are depicted below.

The Friends of Hunting Creek are in it for the long run. By continuing to test the streams for nitrogen each spring during the Water Quality Blitz, the FOHC is keeping a close eye on how the watershed responds to ongoing development in the Prince Frederick Town Center, a changing climate, and other emerging pressures. Each additional year of data strengthens the long-term record and helps identify statistical trends that can guide local land-use decisions and conservation/restoration efforts. While five years is just the beginning, the results so far are mostly good. And, with a dedicated community of concerned residents and citizen advocates, Hunting Creek is in good hands to stay that way!

Read the full Nitrogen report here!