First Data Reported for the 39th Year of SMLA Water Quality Monitoring Program
SMITH MOUNTAIN LAKE, VA – A team of 50 Smith Mountain Lake Association (SMLA) volunteers has started the 39th year of water quality monitoring at Smith Mountain Lake. The program kicked off during the week ending May 24 when the volunteers climbed aboard their boats to take water clarity readings and collect water samples at 84 locations on the lake.
Analysis of the collected water samples by environmental scientists at Ferrum College concludes that the current water quality of the lake continues to be very good, despite being temporarily affected by the extended period of rain experienced during the month of May.
The program provides critical data to assess the health of the lake. Samples will be taken every two weeks during the summer season.
The parameters analyzed from these samples are (1) water clarity, (2) levels of chlorophyll-a, and (3) levels of phosphorus.
Water clarity reflects the density of particles suspended in the water, primarily algae and sediment, both of which tend to increase when periods of rain wash sediment and nutrients into the lake from the surrounding watershed. The average water clarity across all sites in the lake for the week ending May 24 measured 1.54 meters, compared to the 20-year average of 1.99 meters during the same period in previous years.
Chlorophyll-a reflects the volume of algae growing in the lake and is expressed in terms of parts per billion (ppb.) The average concentration of chlorophyll-a across all sites for the week ending May 24 was 12.08 ppb, a substantial increase compared to the 20-year average of 6.40 ppb during the same period in previous years. Importantly, despite the recent increase in algae in the water, there still have been no confirmed reports of potentially harmful algae blooms in the lake since 2023.
Phosphorus is a key nutrient for all living organisms. Too much phosphorus in the water can contribute to excess growth of algae. Phosphorus results will be reported when Ferrum College completes the analysis of the samples taken.
These results are an average of all the sites being monitored on the lake. Results from specific locations on the lake may vary significantly from the lake-wide averages. To see more detailed results, SMLA now publishes a series of charts. Results from each of eight zones on the lake are provided.
In addition to the samples collected by volunteers, scientists from Ferrum College collect bi-weekly water samples at 14 locations on the lake and test them for the presence of bacteria. In the week ending May 24, one location was found to have levels of bacteria exceeding the Virginia Dept of Environmental Quality guideline for recreational waters. The affected location was in the upper Blackwater River, near channel marker B49 in the area known as The Horseshoe Bend.
Instances of elevated bacteria typically follow a period of heavy rain during which animal waste from livestock, wildlife, pets, or leaking septic systems are washed into the lake. The instances are usually short-lived because bacteria tend not to thrive in the relatively cool, clean water of the lake. The Virginia Department of Health recommends that people refrain from swimming in the lake immediately after a period of heavy rain.
About SMLA
The Smith Mountain Lake Association (SMLA) mission is to keep Smith Mountain Lake clean and safe. Established in 1969, SMLA is the longest serving advocate for the SML community. Activities help to retain the pristine beauty of Smith Mountain Lake and the vibrant local economy. SMLA is a nonprofit 501(c)(3), volunteer-led organization that relies on memberships, donations and grants to support programs that protect SML.
