about south river federation

The South River 2016 Report Card is out! 

Generally, the River is holding the line and remaining resilient. The River's overall grade improved, while the scores of key indicators like dissolved oxygen and water clarity decreased, the scores of many others including bacteria and nutrients improved. One key improvement was the improvement in underwater grasses, while still only at 3% of their historic levels, the South River saw a record increase in acreage from 2015.


 Is It Swimmable?

As a part of "Operation Clearwater" the Federation samples and tests for bacteria at popular South River swimming beaches during the summer. In 2016, the River as a whole had passing scoared 89% of the time, a 10.5% improvement over 2015. The Environmental Protection Agency (EPA) sets a limit of 104 cfu (colony forming units)/100mL  of water for recreational contact and does not advise swimming within 48 hours of a rain event due to high predicted bacteria levels.

Restoration Success - In 2016, the Federation restored the most polluted stream segment on the River, a portion of Church Creek that runs behind Annapolis Harbour Center, as part of our Church Creek Initiative. Within one year of restoration, mean bacteria levels improved by 60% -- making progress towards meeting the EPA's bacteria limit!


Is It Fishable?

Dissolved oxygen and water temperature are two variables that are closely linked. Just like a cold soda holds more carbonation that a warm (and now flat) one, colder water holds more gas (or more oxygen) than warm water. The South River saw a slight drop in dissolved oxygen in 2016, despite a decrease in water temperature. How did this happen? We think it might have to do with algae...



The South River also saw a large increase in chlorophyll (a pigment found in algae) from 2015. Elevated chlorophyll levels suggest periods of increased algal blooms. When these algae blooms start to decompose, they suck the oxygen out of the water, creating hypoxic (low oxygen) waters that are harmful to fish and other wildlife. The South River did see two small fish kills in 2016, but nothing like the significant fish kills experienced on Middle River and elsewhere on the Bay. 



Underwater grasses were also found all over the South River in 2016! In total, 14.85 acres were found in the Virginia Institute of Marine Science Underwater Grass Aerial Mapping survey, which is an 85% increase from 2015. The Federation also conducted its own "Great Underwater Grass Hunt" and found large amounts of Horned Pondweed and even a small patch of Eurasian Milfoil. 




What Does This Mean for the South River?

Overall things are improving slowly. The dissolved oxygen and water clarity downturns are concerning, but hopefully they can be resolved with continued targeted restoration.