Lake Water Quality Monitoring Yields Good Results for 2025
SMITH MOUNTAIN LAKE, VA – Smith Mountain Lake Association (SMLA) has released the final report from water quality monitoring in 2025. The results for parameters tested are in line with the 20-year averages, which is very good news for the health of Smith Mountain Lake.
“The key conclusion of the report is that the water quality in Smith Mountain Lake is very good,” said Tom Hardy, SMLA Water Quality Monitoring Program committee chair.
Results Improve Over the Months in 2025
Early 2025 test results showed unfavorably elevated levels of phosphorus and algae and reduced water clarity, mostly related to multiple bouts of heavy rain in May. Each of the tested parameters improved significantly as the summer progressed. Full year 2025 averages are in line with historical 20-year averages and only slightly inferior to 2024.
The 2025 Water Quality Monitoring Program report is posted on the SMLA website. The report shares 84 pages of technical data and scientific analyses.
Three key parameters are sampled to assess the trophic status of the lake. These are:
- Chlorophyll-a concentration, which is an indication of algae in the water.
- Total Phosphorus, an important nutrient that in large amounts can contribute to excess growth of algae.
- Water clarity, which reflects the density of particles suspended in the water, primarily algae and sediment.
These parameters can vary for different parts of the lake. The uppermost areas of the lake experience less favorable results than the lowermost areas that are closer to the dam. The nutrients and sediment that flow into the lake from the surrounding watershed tend to gradually settle out from the water as it winds its way downstream toward the dam.
Ferrum College and SMLA Collaborate to Monitor Water Quality
The Water Quality Monitoring Program was established in 1986 as a collaborative effort between SMLA and Ferrum College. The goal is to monitor the overall health of the lake.
The program involves about 50 citizen volunteers who take water samples and water clarity readings at 84 sites on the lake every two weeks during the summer. Seven faculty members and three students from Ferrum College take additional readings on the lake. All samples are processed at Ferrum College.
Additional parameters sampled by Ferrum College faculty and students provide additional information about the health of the lake.
- Levels of E. coli bacteria throughout the summer were found to be within acceptably low levels defined by the Virginia Department of Health.
- Phytoplankton species in the lake were dominated by green algae and diatoms and there was a relatively low presence of potentially harmful cyanobacteria or blue-green algae. There were no confirmed reports of toxic algae blooms in the lake in 2025.
- Water temperature profiles demonstrated the thermal stratification of the lake is occurring earlier each year. This causes a reduced level of oxygen in lower depths and forces cold water fish to migrate closer to the uncomfortably warm surface. This phenomenon is largely climate driven.
The SMLA Water Quality Monitoring Program is funded by Appalachian Electric Power, Bedford Regional Water Authority, Western Virginia Water Authority, Virginia Department of Environmental Quality, and donations to SMLA from local businesses and citizens.
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.
Water quality monitoring volunteers Ron and Daphne Jamison check water clarity.
Volunteers Larry Sakayama and Mark Earnhardt conduct water sampling as part of the SMLA Water Quality Monitoring program.
