My cool watershed

Water Clarity

Underwater plants depend on sunlight to grow, which can be blocked by poor water clarity.

> 1.0 m Good
0.6-1.0 m Adequate
< 0.6 m Poor
N/A No data within past year

Bottom Dissolved Oxygen (D.O.)

Many forms of aquatic life require adequate levels of oxgyen to survive.

> 6 mg/L Good
3-6 mg/L Adequate
< 3 mg/L Poor
N/A No data within past year


Description of conductivity

< 3 mg/L Poor
3-6 mg/L Adequate
> 6 mg/L Good
N/A No data within past year


High levels of bacteria in water indicates contamination from fecal matter, which can bring harmful viruses.

< 104 cfu/100mL Good
> 104 cfu/100mL Poor
N/A No data within past year


The Federation believes in a holistic approach to cleaning up the South River. We utilize all available tools, ranging from scientific water quality monitoring, to rain garden installation, to large-scale stream restoration, to one-on-one landowner education.

Rain garden
Living shoreline
Green roof
Legend off / on
Station name

How Healthy are the South, West, and Rhode Rivers?

The Arundel Rivers Federation measures many different parameters to learn about the water quality of the South, West, and Rhode Rivers. We hope this map helps answer three basic questions about the health of our rivers: Is it safe to swim? Can fish breathe? How dirty is it?  For the purposes of this map, we have assigned a parameter for each question.
  • Bacteria levels help determine whether it is safe to swim.
  • Dissolved Oxygen levels show how well fish can breathe.
  • Water Clarity helps measures the amount sediment (dirt), which is our worst pollutant in terms of causing harm to aquatic life.
Restoration Projects Sediment and excessive nutrients are our two worst pollutants.  The Federation actively develops and oversees projects that work to trap and filter these pollutants before they reach the South, West, and Rhode Rivers.  Our restoration projects range from tiny rain gardens to multi-million dollar stream restorations – check them out under the “Restoration” tab.


Check out our website for more information. Having trouble with the map? Let us know at [email protected].






        More information


        Bacteria readings measured in CFU’s (Colony Forming Units per 100 ml)