Stream Intended Use
|While some are in better condition than others, streams in Mecklenburg County are not as clean as they should be. Work is being done to improve streams that are impaired and to protect those that currently meet water quality standards. |
Stream Intended Use
Streams are classified by the NC Division of Water Quality for a variety of beneficial uses. In Charlotte-Mecklenburg, all streams have been classified as Class C
. That means the water is to be protected for "secondary recreational uses" with occasional human contact such as fishing and wading. To assess stream health, Charlotte-Mecklenburg calculates the Stream Use Support Index
The greatest negative impact
The discharge of untreated, undetained runoff from impervious surfaces has the greatest negative impact to surface water quality. In 2007 and 2008, the City of Charlotte, Mecklenburg County and the Towns adopted ordinances to address these impacts. These ordinances apply to new development and redevelopment but do not apply to existing development. The jurisdictions are actively involved in restoration efforts to address water quality impairment from existing development through the use of storm water fees and grant funds.
Bacteria is another problem
More than 300 major stream miles are monitored for more than a dozen parameters at least monthly by Charlotte-Mecklenburg Storm Water Services (CMSWS). Each parameter is an independent measure of water quality and the monitoring results are combined to calculate the SUSI.
Fecal coliform bacteria
levels are among the parameters monitored to determine compliance with Class C criteria. In the graph above, lower levels of fecal coliform result in a higher percentage of stream miles suitable for human contact.
The data for the graph is generated from quarterly stream samples taken during base flow conditions. Bacteria levels are usually lower during base flow conditions but increase significantly during and after heavy rainfall. Sources of fecal coliform include sanitary sewer overflows and waste from wildlife, pets and farm animals.
Other ways of monitoring stream health
Additionally, CMSWS performs 24-hour in-stream monitoring through the Continuous Monitoring and Alert Notification Network
(CMANN). Pollution sources are often identified through stream walks, citizen complaints, industrial inspections and various other activities.
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The trends shown in the State of the Environment Report are not all based on tests of statistical significance. Data analysis, anecdotal evidence, and best professional judgment have been compiled to represent these trends. The State of the Environment Report takes a snapshot of important environmental indicators in an effort to educate the public while highlighting challenges, successes and the general direction of change for each indicator. For additional information on these indicators and the determination of trends, please follow the links and feel free to contact the appropriate resources.
Last updated 2/17/14