https://smlassociation.org/wp-content/uploads/2025/07/2025-07-Gale-Chaney-scaled.jpg 1920 1440 Jill Kurtz https://smlassociation.org/wp-content/uploads/2020/11/SMLA-Logo-Web_Main-Logo.png Jill Kurtz2026-04-21 12:02:252026-04-21 12:02:25Water Quality Monitoring Volunteers NeededWater Quality Monitoring
SMLA and Ferrum College have been monitoring the water quality of SML since 1987. Each summer, volunteers from SMLA monitor the lake for nutrients, bacteria and algal blooms. Stakeholders and local health departments use the data to inform the community of any concerns.
Smith Mountain Lake Water Quality Monitoring Zone Map
Click on a number on the map regions to see water quality readings for specific areas of the lake.
2026 Lakewide Results
SMLA water quality monitoring volunteers conduct water sampling sessions every 2 weeks during the summer season. Water clarity readings are taken at 84 sites on the lake and water samples are collected at 56 sites. Results are posted here.
2026 Weekly Trend
20-Year Trend
Water clarity – a measure of how “see-through” water is, which is influenced by factors like turbidity (cloudiness), algae abundance, and the presence of pollutants. The higher the number the better. It can be adversely affected by algae growth triggered by an excess of phosphorus in the water, or suspended dirt and silt triggered by boat traffic and runoff from the surrounding watershed caused by heavy rain.
Chlorophyll-a – the green pigment that plants and algae produce. It can be used as a proxy for the amount of algae growing in the water. A certain amount of algae is considered normal and beneficial to the lake ecosystem, but at high levels can be an indication of excessive and potentially harmful algae growth.
Phosphorus – an important element required by all life forms. In small amounts it helps support a healthy lake ecosystem, but in excessive amounts it can trigger harmful algae blooms.
Large man-made lakes like SML typically experience significant variation of these three measures from one section of the lake to another. The areas with the best clarity and lowest Chlorophyll-a and phosphorus are those which are farthest downstream. Small coves and areas which are furthest upstream tend to have lower clarity and higher Chlorophyll-a and phosphorus.
News
https://smlassociation.org/wp-content/uploads/2025/07/2025-07-Gale-Chaney-scaled.jpg 1920 1440 Jill Kurtz https://smlassociation.org/wp-content/uploads/2020/11/SMLA-Logo-Web_Main-Logo.png Jill Kurtz2026-04-21 12:02:252026-04-21 12:02:25Water Quality Monitoring Volunteers Needed
https://smlassociation.org/wp-content/uploads/2026/04/Image1.jpg 1018 1535 Jill Kurtz https://smlassociation.org/wp-content/uploads/2020/11/SMLA-Logo-Web_Main-Logo.png Jill Kurtz2026-04-09 12:30:322026-04-09 12:33:5640 Years of Water Quality Monitoring at Smith Mountain Lake
https://smlassociation.org/wp-content/uploads/2025/03/Press-Release-2.png 400 600 Jill Kurtz https://smlassociation.org/wp-content/uploads/2020/11/SMLA-Logo-Web_Main-Logo.png Jill Kurtz2026-02-09 22:16:442026-02-09 22:16:44Lake Water Quality Monitoring Yields Good Results for 2025Want to learn more or volunteer?
CONTACT WQM@SMLASSOCIATION.ORG
Water Quality
What is the yellow film that I see floating on the surface of the water?
Virginia is well known for the prodigious amount of pollen that blows from the trees every year, particularly during the spring. Depending on the direction of the wind, pollen can accumulate as a yellow film close to the shoreline. This should not be confused with the blue-green film that may indicate a potentially harmful algal bloom.
Is it okay to blow leaves on my property into the lake?
While we can’t stop trees along the shoreline from dropping their leaves into the lake, it is not advised for homeowners or landscapers to blow leaves into the water. As leaves decay they release phosphorus and other pollutants into the water which can stimulate excess algae growth and may trigger a harmful algae bloom. It is against Virginia state code to blow leaves into the lake.
What products are safe to use for cleaning my dock and boat?
Plain water or pressurized water are the safest options for cleaning around lake water. Many soaps and detergents add nutrients to the water which can promote algae bloom, which harms fish and other aquatic life. Make sure if you do use a product that is environmentally friendly and is free of phosphates and chlorine.
Is it safe to swim where geese congregate?
No, e coli is present in goose feces.
Is SML safe to swim in?
All water quality monitoring work for the past 38 years at Smith Mountain Lake indicates that levels of nutrients and bacteria are not found at levels that would cause a risk to human health. Like any natural body of water always use common sense when swimming and “when in doubt, stay out.” Be sure to shower after swimming and keep children and pets from drinking the water. Refer to https://www.vdh.virginia.gov/