2022 Water Quality Data
For the South, West, and Rhode Rivers
Who is Arundel Rivers?
Arundel Rivers Federation's three key programs-- restoration, monitoring, and outreach-- are designed to achieve its mission: to protect, preserve, and restore the South, West, and Rhode Rivers by working with local communities to achieve clean, fishable, and swimmable waterways for present and future generations.
In 2022, the Arundel Rivers monitoring team collected water quality data at 42 stations weekly on the South, West, and Rhode Rivers from May to October.
At each station, scientific monitoring probes (YSI and Hydrolab) were used to collect pH, temperature, dissolved oxygen (DO), salinity, and conductivity data. A secchi disk measured water clarity.
Arundel Rivers work is possible because of your support! If you'd like to learn more about our programs, find ways to volunteer, or donate please go to arundelrivers.org !
South, West, and Rhode Scores
All of our data collection and scoring is done according to Mid-Atlantic Tributary Assessment Coalition (MTAC) protocols.
The color gradient illustrates water quality in the areas in between and surrounding the stations. Bright green would indicate areas that scored high, up to a 100% (A+); dark red would indicate areas that scored as low 0% (F). Light greens, yellows, and oranges indicate everything in between.
South River score: 56% (C+)
In this map, each of the South River's 18 stations and their overall scores are displayed. The average of all 18 stations' scores determines the South River's total score of 56% (C+).
A station's overall score is calculated by averaging the dissolved oxygen (DO) score and clarity score together, then assigning it a corresponding letter grade.
As you can see, all of the South River stations scored in the B and C range in 2022. The South River's 2022 score was similar to its 2021 score of 57% (C+).
We consistently see a trend of declining water quality as we travel upstream. There is less tidal influence and mixing in our shallow water upstream tributaries. This also indicates that the majority of our pollution is coming from our own watershed and land uses— a great opportunity for restoration projects!
Rhode River score: 57% (C+)
The Rhode River's higher score, compared to the South and West, may be due to different land uses. The Rhode River watershed has a higher percentage of forested land use compared to both the South and West River. Specifically, the Rhode River watershed is 54% wooded, the West River watershed is 44% wooded, and the South River watershed is 46% wooded. This means that there is likely less stormwater and agriculture runoff entering the Rhode River, reducing dead zone impacts and erosion.
West River score: 52% (C)
Overall, the stations of the Rhode and West Rivers received scores of B's and C's. Both rivers also scored similarly in 2021: the Rhode scored 57% (C+) and the West scored 56% (C+).
Similar to the South River, the mouths of the West and Rhode Rivers are healthier than the tributaries. The mouths of our rivers receive more flushing and influence from the mainstem of the Bay. As we go upriver, tidal flushing and depth lower, resulting in higher concentrations of pollution and less open water influence.
Dissolved Oxygen
Dissolved oxygen (DO) is a key indicator of ecosystem health since almost all aquatic organisms require DO to survive.
Use this key to interpret the box and whisker plots below:
This box and whisker chart shows the distribution of dissolved oxygen (DO) values for each station on the South River. The red line indicates 5 mg/L, which is the pass/fail threshold.
We see dead zones (areas with DO below 5 mg/L) often in the summer on the South River. The data highlighted by the red bar illustrates potential dead zones in the South.
Dead zones and low oxygen at bottom depths are a result of eutrophication, or too much nitrogen and phosphorus entering our waterways. These excess nutrients cause algal blooms.
A potential algal bloom is circled on Aberdeen Creek. Algal blooms produce high levels of oxygen. Oxygen is then removed from the water as those algal blooms die and decompose, making it unsuitable for many species.
This is why Arundel Rivers is working to reduce nitrogen and phosphorus from entering our waterways. Arundel Rivers will begin monitoring for nitrogen, phosphorus, and algae in the 2024 monitoring season to give us a deeper understanding of where this is happening in our rivers.
If you want to learn more about water quality issues and pollution sources, visit arundelrivers.org !
DO values on the Rhode River were better than those of the South - this is a trend we generally see.
The West River also saw mostly passing DO levels.
Clarity
Clear water supports the growth and survival of aquatic plants which support fish, crabs, and oysters.
This graphs illustrates the average secchi disk depth for all stations on one sampling day. The West River had both the highest and lowest average clarity readings.
The Mid-Atlantic Tributary Assessment Coalition (MTAC) protocols also provide guidelines for clarity. A score of 5 indicates excellent water clarity while a score of 0 indicates poor water clarity.
The South River's secchi disk readings received a score of 2 for the entire monitoring season. The West and Rhode Rivers' secchi disk scores ranged from 3 to 1 throughout the season.
Interactive Data Maps
Explore grades and scores for each station using the map below.
Click on stations to view individual data points by date.
