Smith Mountain Lake was given a clean bill of health in a report provided by the Smith Mountain Lake Association last week. While it was good news from the organization’s water quality monitoring team, they did share a few concerns that lake residents should be aware of.
The biggest positive from this year’s annual water quality testing program was the sharp decline in the number of times E.coli was found at high levels at the lake compared to previous years. During the six times the lake waters were tested between Memorial Day and Labor Day, E.coli levels above the Virginia Department of Health standard for recreational swimming were only exceeded once during testing on June 16.
The testing is done at multiple locations around the lake throughout the summer. The June 16 testing found high levels of E.coli in the area of Bay Rock Marina and Crystal Shores Marina. The report noted that the level of E.coli found at Crystal Shores Marina was only slightly above the VDH standard.
“We expected with all the rain we would have worse results,” said Mike McCord, SMLA’s director of the water quality monitoring program.
High E.coli levels are traditionally found in areas of the lake after heavy rains. McCord said one likely cause is due to runoff from farms with cattle whose waste can leak into the lake.
While this year’s results are positive for anyone who uses the lake for recreation, McCord warned that one year does not constitute a trend. He said lakefront property owners should still be vigilant about what enters the lake.
Phosphorus is also something that McCord said he would like to see less of in water quality tests. It is a major factor in algae growth in the lake as well as decreased water clarity, which was also a concern this year.
While phosphorus levels decreased slightly this year compared to last year, levels have been increasing dramatically since 2012. Since that year phosphorus levels in the lake have nearly doubled.
Phosphorus is found in fertilizers used in lawn maintenance for many lakefront properties as well as produce farms near the shoreline. An increase in phosphorus getting into the lake can lead to algae blooms that can be harmful in the lake. While small amounts of algae are essential for a healthy lake, large amounts can decrease oxygen in the water and harm other lake organisms such as fish.
The SMLA created an algae reporting tool earlier this year to track high concentrations of algae around the lake. Anyone who finds algae on the lake can visit bit.ly/SMLAlgae to report it.
The new reporting tool was put in place in July, McCord said, although much of the algae had already disappeared by the time it was set up.
Of the algae that was found and examined around the lake by SMLA volunteers this year, 73% was green algae, 14% was diatoms and 13% was blue-green algae. Only the blue-green algae can sometimes be harmful to humans and pets due to a toxin it produces. Fortunately, McCord said the blue-green algae found was not the type that produced the harmful toxin.
McCord warned that if phosphorus continues to increase in the lake in the future, algae will likely increase as well. Some of that algae could also possibly be some of the more harmful blue-green algae.
McCord encourages lakefront property owners to create buffer landscapes along the shoreline to prevent excess phosphorus from entering the lake.
“It can’t hurt, and it will help,” McCord said of buffer landscapes.