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What's the Water Quality of Mecklenburg County Lakes?

Sailboat on lake    The Lake Use Support Index (LUSI) shows the water quality in each lake bordering Mecklenburg County. If a lake meets North Carolina's water quality standards, it is considered supporting of its designated use.

Among other things, the LUSI score shows if the lake water is safe for swimming. Any fish consumption advisories are also indicated.

Current LUSI scores:

    • Lake Norman: Highly Supporting – all sites        
         See the LUSI map for Lake Norman 
            A fish consumption advisory is in effect

    • Mountain Island Lake: Partially Supporting to Highly Supporting
         See the LUSI map for Mountain Island Lake 
            Fish consumption advisories are in effect for more than one species

    • Lake Wylie: Highly Supporting – all sites​        
        See the LUSI map for Lake Wylie 
            Fish consumption advisories are in effect for more than one species

More about fish consumption advisories

Currently, there are no advisories urging people not to swim in lakes bordering Mecklenburg County. More about swimming advisories.

Local lakes are considered natural bodies of water. Certain precautions should be taken when swimming in natural bodies of water to protect your health.

See the latest Lake Monitoring Report​ and how our lakes' water quality compares to state standards

Measuring water quality in our lakes

Charlotte-Mecklenburg Storm Water Services collects water samples from local lakes six times a year. There are 28 monitoring sites on the lakes that are sampled each time.

The data are grouped into categories that show the most troublesome pollutants and indicators of environmental health. Using the data, Storm Water Services creates the LUSI maps, tracks trends in lake water quality, and pinpoints specific water quality problems.

We check:

• Water temperature
• Dissolved oxygen (can the fish breathe?)
• Conductivity (the chemical makeup of polluted water allows electricity to flow through it more easily)
• pH (is the water acidic, alkaline or neutral?)
• Turbidity (how murky is the water?)
• Chlorophyll, Total Phosphorus, Nitrate-Nitrogen (any algae blooms?)
• Fecal coliform bacteria (any sewage spills affecting the water?)
• Toxic metals (hazardous to fish and other aquatic life)
• Volatile Organic Compounds (such as petroleum additives that pollute waterways)

testing water quality


Storm Water Services also tracks water quality in our streams.

How we test water quality in our streams and lakes

See a video of Storm Water Services staff testing lake water quality

Request water quality data

Protecting the Water Quality in our Lakes (booklet)