Wicomico Creekwatchers

The Wicomico River Creekwatchers program develops objective scientific data to monitor water quality. Biweekly, from mid-March through early November, about 50 trained volunteers collect water samples and record weather conditions at 26 sites along the Wicomico River and its tributaries, from Delmar to Mount Vernon. 

Salisbury University student volunteers, under the direction of science faculty, analyze water samples for total nitrogen, nitrates, total phosphorus, phosphates, salinity, chlorophyll A, and bacteria levels. Below you can find monthly data at selected sites presented alongside long-term averages using up to 20 years of data, and you can view trends month-to-month depending on the season and weather. 

The results of each sampling season are presented in an annual report. Local government officials use these reports to guide decisions that could affect the health of the river or Chesapeake Bay. All reports are available to view below. 

Interested in becoming a Creekwatcher? Let us know here.

Takeaways from 2022

The 2022 sampling season showed that the Wicomico River watershed continues to improve in several water-quality measures. Freshwater and pond sites showed slightly increased water clarity and a significant drop in chlorophyll a compared to long-term averages over the past two decades. Dissolved nitrates and total nitrogen levels, though still elevated at many sampling sites, were below the level of concern. Dissolved nitrates, in particular, showed significant improvements over the long-term averages.

On the other hand, while dissolved phosphate showed a significant decrease compared to the long-term average, total phosphorus was significantly higher in 2022 than the long-term average. This continued upward trend now indicates that all types of sites sampled have crossed the threshold to be considered impaired; however, these opposite trends between dissolved and total phosphorus likely indicate releases from stored phosphorus as the riverbed is disturbed rather than increased new inputs to the watershed.

The Wicomico River is becoming saltier, with lower (southern) portions of the river significantly saltier in 2022 than the long-term average. This is consistent with sea-level rise along the Mid-Atlantic coast. Saltwater incursion brings with it a higher pH (increased alkalinity) in those same areas.

Bacterial counts, taken at a larger number of sites for the 2022 bacterial sampling season (Memorial Day to Labor Day), showed mixed results. At some sites (Johnson Pond, Schumaker Pond, River Wharf), the bacterial count was low enough for swimmability on 100% of sample dates, better than the long-term averages. At other sites (Northwest Wicomico, Wikander), the water had bacterial counts low enough to be considered swimmable on more than 50% of the sample dates. In the ponds, bacterial counts considered unsafe for swimming occur mostly in late spring and early summer; in the tidal portions of the river, elevated bacterial levels tend to begin in July.

But there is a lot more to safe swimming than just bacterial counts. For your safety, avoid swimming in any portion of the river or its tributaries without checking with the Wicomico County Health Department first.

Monthly Wicomico River Updates

The charts below display data on salinity, chlorophyll A, coliform bacteria, pH, nitrate, phosphate, and water temperature from four sites on the river, updated monthly during the sampling season (March to November). Each chart presents an average of two samples collected each month during the sampling season. These numbers represent "raw" data collected in the field (water temperature) or from laboratory testing at Salisbury University’s biology department. This information represents water conditions at the specific collection time and lacks context needed to determine the waterway’s longer-term health. The numbers that appear in the annual report (see links to past reports above) do have the context needed to determine the overall condition of the water. Trends emerge over time, both during the course of a sampling season and also long-term when viewed in the context of the 20 years that Wicomico River Creekwatchers has been collecting this data.

In all of the charts, the same four site codes appear across the bottom from left to right, representing data from a pond (SCPO, Schumaker Pond), the main stem of the river next to the Port of Salisbury Marina in downtown Salisbury (BRRI), Pirates Wharf (PIWH), and Whitehaven (WHVN), near the southern end of the river. 


Here's what it means. Salinity is a measure of brackishness, or saltiness. In general, the closer you are to the Tangier Sound and Chesapeake Bay itself, the saltier the water becomes. As we would expect, the ponds (SCPO) and farther up-river sites (BRRI) have very low salinity while those closer to the Bay (PIWH and WHVN) are much saltier. Salinity levels can be affected by heavy rainfall and sea-level rise. 

Chlorophyll A 

Here's what it means. Chlorophyll A is a measure of plant growth in the water, primarily algae, which is present in the water regardless of its visibility. The dashed line in this graph at 40 ug/L is the level of concern, where high algal growth can negatively impact life in the water. While we would expect the monthly levels to rise and fall over the course of the sampling season, we are looking for the orange bars to remain well below the dashed line.


Here's what it means. In 2023, for the first time, all Wicomico River Creekwatchers volunteers are collecting a second sample for bacterial besting from all of its 26 sites throughout the season. This will provide much greater context and awareness of trends throughout the season (compared to the eight sites previously sampled for bacteria only from Memorial Day through Labor Day). The dashed line at 104 MPN/100mL represents "safe swim level." The presence of large numbers of fecal coliform bacteria may indicate proximity to failing septic systems (private or public). The most dramatic illustration of this was in 2017, the year Salisbury's current wastewater treatment plant (WTP) began operations, and bacterial counts in the river downstream of the plant plummeted. The light gray bar shows the long-term average after the WWTP plant began operation, which brought the average below the dashed line


Here's what it means. pH measures acidity or alkalinity. Pure water is perfectly neutral with a pH of 7. For a river, the ideal pH is around 7.4, or slightly alkaline. The pH of a river, pond or other body of water is affected by acid rain, plant decomposition, agricultural runoff and other pollution. Lower pH (acidic) can be found near power plants, landfills, or large animal farms. Carbon dioxide also lowers pH. The Wicomico River's pH is not remarkable in either direction and appears relatively stable. 


Here's what it means. Nitrate is a form of nitrogen found in fertilizers, wastewater, landfills, animal waste, septic systems or urban drainage. Nitrate is a necessary nutrient for plants, but overuse in fertilizers and farm fields leads to nitrate finding its way into waterways where it encourages overgrowth of algae and other aquatic vegetation. The dashed line in this graph represents the level where nutrients are high enough to cause algal blooms and other negative effects. So while the long-term average levels exceeded this concentration, recent nitrate measures have been trending downward.


Here's what it means. Phosphate is another plant nutrient that can contribute to overgrowth of aquatic vegetation, including algae. Phosphate is also found in fertilizers, and its origin on the Shore is largely from poultry manure, which was for many years overused to fertilize crops. Phosphate levels are not dropping as quickly as nitrate levels, but it is a nutrient that does not break down in soil as quickly as nitrate. It will take years for it to dissipate in the soil, but the good news is that it is not increasing now, generally.


Here's what it means. Water temperature is measured in the field as volunteers are recording other atmospheric and weather conditions while taking samples. We would expect water temperatures to rise and fall over the sample season.