Monitoring Overview

Monitoring surface water quality is one of the best ways to protect streams and lakes. It helps identify problems, determine whether streams and lakes are improving or declining over time, and most importantly it helps protect quality of life and public health.

Each year, a wide range of surface water quality monitoring data is collected from streams and lakes throughout the City of Charlotte and Mecklenburg County.

  • Almost 15,000 water samples are collected per year and over 20 different parameters are routinely screened
  • Automated samplers at 35 locations measure five parameters per hour, 24 hours a day. This equals approximately 1.5 million measurements a year
  • Fish communities are assessed at five locations
  • Macroinvertebrate communities are assessed at 34 locations

To learn about techniques used to monitor local streams and lakes, please see the following videos:

This webpage is organized into four interest areas related to Surface Water Quality Monitoring. Please view any of the following links for more information about these topics.

There are several technical terms used on the monitoring pages above. Please see our Glossary of Monitoring Terms(PDF, 62KB) for help understanding some of the most common ones used. 

Additional Monitoring Programs

Monitoring of stormwater outfalls, industrial and municipal facilities, septic systems, and Stormwater Control Measures is also conducted to improve stormwater quality and help keep our streams and lakes healthy. Information about these programs can be found as part of the Illicit Discharge Detection and Elimination Program and Pilot Stormwater Control Measures Program


Olivia Edwards
Mecklenburg County Environmental Supervisor

Monitoring Data

Monitoring data being collected currently and in the past is available. Please scroll down for more information.

  • Request for data records
  • Data collected every hour/ 24 hours a day

Request for data records

The following records are available upon request and at no cost. Only electronic versions of data are available from 1985 to present.

  • 1969 – 1984:  Handwritten into logs. Many are still on file.
  • 1984 – 1993:  Lotus database
  • 1994 – 2004:  FoxPro based data management network
  • 2004 – Present: Custom water quality database application.

We welcome you to submit a request for surface water quality data. A minimum of two weeks is required for staff to process the request form and release the data. To submit a request, please fill out the Water Quality Request Form.

Staff follows strict Quality Assurance and Quality Control (QA/QC) practices when collecting field measurements or surface water quality samples. When samples are delivered to a laboratory, the laboratory is required to provide finalized data electronically and in hard copy to the QA/QC officer within forty-five days. All field and laboratory data received by the QA/QC officer is compiled, reviewed, verified, validated, and warehoused. 

Questions about data management and QA/QC?

Robert Sowah
Mecklenburg County Environmental Analyst

Continuous Monitoring - Data collected every hour 24 hours a day

The Continuous Monitoring and Alert Notification Network (CMANN) is comprised of a network of automated monitoring stations where data is being collected throughout Charlotte and Mecklenburg County every hour, 24 hours a day! Please see our CMANN website to see where and what data are being collected and to use its powerful data management tools. Our CMANN website contains a wealth of stream data and reporting tools that can help you better understand all the stream data being collected. Staff uses CMANN data and this website to identify both short and long-term changes in water quality. 

Questions about CMANN? 

Ryan Spidel
Mecklenburg County Environmental Supervisor

Monitoring Techniques

Staff performs six different types of monitoring in local streams and lakes. Information about what is monitored, how it's done, and where it occurs is organized as follows. Please scroll down for more information about these topics.

  • Fixed Interval Monitoring
  • In-Stream Stormwater Monitoring
  • Lake Monitoring
  • Biological Monitoring
  • Stream surveys
  • Continuous Monitoring and Alert Notification Network

Rain and water levels in streams and lakes across Mecklenburg County are also monitored with 71 rain gauges, 3 lake gauges, and 50 stream gauges. Please see gauges and hydrologic data in and around Charlotte and Mecklenburg County for more information.

Fixed Interval Monitoring

For Fixed Interval Monitoring (FIM), staff either collects a surface water sample ("grab sample") for analysis in the lab or they test the water right at the stream or lake with a hand-held meter. See this map of FIM locations(PDF, 703KB) where the following parameters are measured monthly.

  • Temperature
  • Dissolved Oxygen
  • Enterococcus Bacteria
  • Ammonia Nitrogen
  • USGS Suspended Sediment Test (SSC)
  • Zinc (dissolved)
  • Arsenic
  • Nickel
  • Silver
  • Chromium
  • Beryllium
  • Conductivity
  • Fecal Coliform Bacteria
  • pH
  • E-coli Bacteria
  • Nitrite and Nitrate
  • Total Kjeldahl Nitrogen
  • Total Phosphorous
  • Suspended Solids (TSS)
  • Suspended Solids
  • Turbidity
  • Hardness
  • Copper (dissolved)
  • Lead (dissolved)
  • Cadmium

In-Stream Stormwater Monitoring

For In-Stream Stormwater Monitoring, automated samplers collect several samples during a storm event. As the flow of a stream increases, the number of samples being collected increases too. This provides information about pollutant levels during the ENTIRE storm. Samples are combined into a composite sample and tested for the following parameters. See this map of In-Stream Stormwater Monitoring locations(PDF, 702KB). The following parameters are measured at each location:

  • Temperature
  • Dissolved Oxygen
  • Enterococcus Bacteria
  • Ammonia Nitrogen
  • Turbidity
  • Chromium
  • Zinc
  • Lead
  • USGS Suspended Sediment Test (SSC) 
  • Conductivity
  • Fecal Coliform Bacteria
  • pH
  • E-coli Bacteria
  • Nitrite and Nitrate
  • Total Kjeldahl Nitrogen
  • Total Phosphorous
  • Suspended Solids (TSS)
  • Copper

Lake Monitoring

For Lake Monitoring, staff collects surface water samples and information about lake conditions six times a year across three lakes: Lake Norman, Mountain Island Lake, and Lake Wylie. See this map of Lake Monitoring locations. The following parameters are measured at each location:

  • Secchi Disk depth
  • Conductivity
  • Alkalinity
  • Total Kjeldahl Nitrogen
  • Nitrate + Nitrite 
  • Temperature
  • Dissolved Oxygen
  • pH
  • Fecal Coliform Bacteria
  • Ammonia Nitrogen 

Biological Monitoring

For Biological Monitoring, staff assesses fish and macroinvertebrate, or "bug", communities twice a year. Different types of fish and macroinvertebrates are more sensitive or tolerant to pollution than others. Staff can assess the health of a waterbody by the types of fish and macroinvertebrates they find. Fish and macroinvertebrates can be one of the best holistic indicators for assessing water quality. See this map of Biological Monitoring locations(PDF, 702KB)

Stream Walks

For Stream Walks, approximately 20% of all streams in watersheds over 50 acres throughout Charlotte and Mecklenburg County are walked by staff in an effort to find illicit discharges and document watershed conditions. This equals an average of approximately 270 miles per year.  This allows staff to walk all these streams every five years. During these walks, the following activities are performed:
  • Documentation of the location, condition, and flow of all outfalls (aka pipes) that are over 12 inches in diameter.
  • Testing of water flowing from an outfall during dry weather. (Stormwater outfalls should typically not have flow during dry weather) 
  • Testing surface water quality at stream junctions and documentation of watershed conditions.

Continuous Monitoring and Alert Notification Network 

The Continuous Monitoring and Alert Notification Network (CMANN) is a network of automated samplers across the County where data is collected once per hour, 24 hours per day. This network provides an automated system that can be especially helpful for identifying problems that need a quick response. The faster staff can respond to a pollution incident, the less potential damage to a stream or lake. A map of current locations is available on our CMANN website.


Stream and Wetland Restoration

Stream and wetland restoration projects are designed to improve surface water quality and aquatic life by reducing erosion and restoring habitat in streams, floodplains and wetlands.

Between 2003 and 2016 Charlotte-Mecklenburg Storm Water Services improved approximately 30 miles of streams and 18 acres of wetlands were either improved or preserved throughout Charlotte and Mecklenburg County.

Stream bank erosion is the largest contributor of sediment in our streams. As streams erode, sediment is deposited downstream, burying aquatic habitat and altering the stability and quality of the stream.

Most stream bank erosion occurs today because of historical stormwater management. Agriculture practices once dredged streams straight, deep and wide. As land was developed, stormwater was piped directly to the nearest stream. Shallow, sinuous (meandering) streams with floodplains containing natural vegetation were converted into deep, straight, eroding channels with floodplains containing developments and few trees or bushes.

Today, it is well known that high quality streams need natural features to be healthy. These features include stable stream banks, wide buffers of woody vegetation (trees and bushes), sinuosity, and unobstructed access to floodplains.

Stream restoration projects reduce erosion and restore
natural features to reduce pollutants,
absorb and dissipate the energy of stormwater,
and keep water temperatures cool and oxygen levels high.

The degree to which each stream restoration project can restore natural features depends largely on the physical constraints of the environment where the stream is located. The more urban the environment, the more likely a project will be constrained by buildings, roads, and other necessary infrastructure and utilities.

Some projects remove structures (i.e., flood prone homes) in the floodplains, allowing for space to improve sinuosity to a stream, plant woody stream corridors, and give the stream access to the floodplain where erosive energy of flood waters can be reduced. Some projects incorporate green infrastructure practices, such as ponds or rain gardens, to reduce stormwater pollutants and manage stormwater flowing into streams. Some do both. Some only have room to stabilize stream bank erosion and restore a small width of native vegetation along stream banks.

Learn more by visiting Stream and Wetland Restoration Projects.

For more information about the importance of Mecklenburg County’s stream restoration projects, check out these videos

Stream Restoration Questions?

Erin Shanaberger
City of Charlotte Watershed Planning & Project Implementation Supervisor

Timothy J. Trautman, PE, CFM
Program Manager, Engineering & Mitigation Program

Stream & Wetland Mitigation Bank

The City of Charlotte's Stream and Wetland Mitigation Bank provides Charlotte with a source of funding for improving streams and wetlands and ensures that some federally required mitigation projects are constructed within Mecklenburg County instead of hundreds of miles away.

Between 2001 and 2020, approximately 24 miles of streams were improved and
34 acres of wetlands were either improved or preserved through the Mitigation Bank.

Municipal projects, such as new roads, schools and water lines, are necessary for a growing community. Occasionally, these projects must impact streams and wetlands. Section 404 of the Clean Water Act requires streams and wetlands impacted by construction to be compensated with the restoration, enhancement, and/or preservation of streams and wetlands in a different location, often at a higher ratio. This is called stream and wetland "mitigation" and must be implemented within the same regulatory watershed where impacts occurred. Unfortunately, regulatory watersheds are very large so mitigation can occur hundreds of miles away from its impact.

In 2004, the City of Charlotte established North Carolina's first municipally owned Stream and Wetland Mitigation Bank where "mitigation credits" are generated when Charlotte-Mecklenburg Storm Water Services restores, enhances or preserves streams or wetlands in Mecklenburg County. These credits can be bought by City or County agencies to offset impacts caused by their construction projects. Once credits are bought, the Mitigation Bank can then fund more local stream and wetland projects.

The Bank benefits local watersheds by ensuring that stream and wetland impacts from City and County infrastructure projects are mitigated within Mecklenburg County, not hundreds of miles away.

An example of a successful Mitigation Bank project implemented by the City is the Edwards Branch Watershed Improvement Project. This project was completed in four phases from 2001 until 2015 and included approximately 7,000 linear feet of stream restoration, 4,400 linear feet of stream preservation, and a little over one acre of wetland preservation. The project also constructed wetlands, a wet pond, a dry detention basin, storm water swales, and buffer enhancements. See Stream & Wetland Restoration Projects for more information.

Another example of a Mitigation Bank project is the Reedy Creek Restoration Project that was completed in 2019. This project includes approximately 25,480 linear feet of stream restoration and enhancement, 14,700 linear feet of stream protection, and 12 acres of wetland enhancement and protection.

For information about how staff selects projects for the Mitigation Bank, which watersheds have mitigation credits available, and the process for requesting credits, see Stream and Wetland Mitigation Bank Project Selection and Credits(PDF, 576KB).

For information about federal regulations that require mitigation of impacts to streams from construction projects, see Section 401 & 404 of the Clean Water Act(PDF, 148KB)

Stream and Wetland Bank Questions?

Erin Shanaberger
City of Charlotte Watershed Planning & Project Implementation Supervisor

Josh DeMaury
Mecklenburg County Environmental Supervisor


Watershed Improvement, Planning & Protection

There are many waterbodies throughout Charlotte and Mecklenburg County that are designated as "impaired" by the State of North Carolina because of degraded water quality and/or degraded habitat and aquatic life. This degradation has largely resulted from the impacts of historical stormwater management practices implemented prior to current surface water quality regulations and the impacts of urbanization.

Watersheds require innovative water quality improvement activities 
to overcome many years of degradation and continued sources of pollution.

We aim to protect and improve the water quality of streams and lakes, so they are no longer considered "impaired". This will require decades of programs that reduce erosion, restore natural features, and reduce polluted stormwater runoff. The following provides information about our programs that accomplish these goals. Please click on any of the links below for more information. 

Watershed Planning

Watershed Planning is the development of watershed management plans that identify why a stream or lake may be experiencing impairments and the programs and management strategies needed to improve these conditions. Impairments are areas of streams or lakes where there is degraded water quality, aquatic habitat or aquatic life.

A variety of watershed plans have been developed to address impairments throughout the City of Charlotte, Mecklenburg County and its six towns. Comprehensive watershed plans will be developed for all of its watersheds to prioritize and maximize watershed improvement activities for many years to come.

For more information about watershed planning please see North Carolina Department of Environmental Quality's Watershed Planning webpage and the EPA's Handbook for Developing Watershed Plans to Restore and Protect Our Waters.

Information about impaired waterbodies in Charlotte and Mecklenburg County and the watershed plans that have been developed is organized on this page as follows:

  • Impairments
  • Goose Creek Watershed
  • McDowell Creek Watershed
  • Rocky River Watershed
  • Irwin, Little Sugar, McAlpine, Sugar Creeks and Lake Wylie Watersheds
  • Reedy Creek Watershed 


In Charlotte and Mecklenburg County, many waterbodies are designated "impaired" as a result of the impacts of urbanization on water quality and aquatic life. The State of North Carolina will typically list a stream or lake on its 303(d) list of impaired waterbodies because a pollutant in the waterbody exceeds the State's water quality standards or it lacks diverse aquatic life (biological integrity).

When the State determines a water body is impaired, it may develop a Total Maximum Daily Load (TMDL) to address this impairment. When the state develops a TMDL, local counties and municipalities must develop a Water Quality Recovery Plan or a TMDL Watershed Plan. These plans identify a strategy for reducing the pollutant(s) of concern within the six minimum measures required by the County and municipalities' National Pollutant Discharge Elimination System (NPDES) Permit. See NPDES permits for the City of Charlotte and Mecklenburg County.  Watershed plans have been developed for all water bodies in Charlotte and Mecklenburg County that currently have a TMDL.

When the State determines a water body is impaired, but it has not yet developed a TMDL, a local municipality may be proactive and develop a voluntary watershed plan. If the State and the U.S. Environmental Protection Agency (EPA) accept this watershed plan, a TMDL will not be developed. These voluntary watershed plans are typically more comprehensive than those required by a TMDL. They usually include local data for pollutants not included on 303(d) lists or in TMDLs and identify improvement strategies and projects that go beyond minimum requirements. 

The Charlotte-Mecklenburg TMDL Watershed Plan(PDF, 5MB) was developed to combine information from several previously developed Water Quality Recovery Plans and provide one comprehensive TMDL Watershed plan to address all of these TMDLs.

Goose Creek Watershed

Goose Creek is on the 303(d) list for impairments related to biological integrity and a TMDL has been developed for fecal coliform bacteria. The watershed also contains the federally endangered species of freshwater mussel called the Carolina Heelsplitter.

For watershed plans that have been developed see the Goose Creek Watershed Management Plan(PDF, 11MB), the Goose Creek Water Quality Recovery Program Plan and the latest Addendum to the Goose Creek Watershed Management Plan(PDF, 526KB)

McDowell Creek Watershed

The McDowell Creek watershed is located in northwest Mecklenburg County and empties into McDowell Creek Cove in Mountain Island Lake where there is a drinking water intake. McDowell Creek is on the 303(d) list for impairments related to biological integrity.

Most of the watershed has been designated as a Water Supply Watershed which means that there are several regulations that aim to reduce the stormwater impacts of new land development. The Town of Huntersville also adopted a Low Impact Development ordinance that further protects the creek. A number of stream restoration projects have been completed in this watershed. See the McDowell Stream Restoration Project Video for an example of one of these projects.

See the McDowell Creek Watershed Management Plan(PDF, 26MB) and the latest Addendum(PDF, 811KB) for the most up-to-date watershed plans. 

Rocky River Watershed

The Rocky River watershed is located in the northern portion of Mecklenburg County with smaller portions in the Towns of Davidson and Cornelius.  Rocky River is on the 303(d) list for impairments related to biological integrity, turbidity and copper, and a TMDL has been developed for fecal coliform bacteria.

For watershed plans that have been developed see the Rocky River Watershed Management Plan(PDF, 7MB), the Rocky River Water Quality Recovery Program Plan(PDF, 2MB) and the latest Addendum to the Rocky River Watershed Management Plan(PDF, 568KB)

Irwin, Little Sugar, Long, McAlpine, Steele, Sugar Creeks and Lake Wylie Watersheds

Seven TMDLs have also been developed for a variety of streams and Lake Wylie. Please see the following list of impaired waterbodies and the TMDLs that have been developed.

Waterbody  TMDL
 Irwin Creek  dissolved oxygen and fecal coliform
 Little Sugar  dissolved oxygen and fecal coliform
 McAlpine Creeks  dissolved oxygen and fecal coliform
 McKee Creek  fecal coliform
 Steele Creek  fecal coliform
 Sugar Creek  fecal coliform
 Irwin, Little Sugar, Long, McAlpine and Sugar Creek  turbidity
 Lake Wylie  TP, TN
 Waterbody's statewide  mercury

Reedy Creek Watershed

The Reedy Creek watershed is a fourteen square mile watershed located in the eastern portion of Charlotte. Reedy Creek is on the 303(d) list for impairments related to biological integrity.  Charlotte-Mecklenburg Storm Water Services has also collected data that indicates pollutants of concern in this watershed. A Reedy Creek Watershed Management Plan is currently being developed that will outline a strategy and prioritized projects to address pollutants and impairments for the entire watershed.

In 2016, the Reedy Creek Stream Restoration project will begin restoring and preserving approximately 7.5 miles of streams and 5 acres of wetlands within and just outside of the Reedy Creek Nature Preserve. Please see the Reedy Creek Stream Restoration website for more information about this project. 

Watershed Planning Questions?

Jason Hunt
City of Charlotte Watershed Planner

Rusty Rozzelle
Mecklenburg County Water Quality Program Manager

Watershed Protection

Protecting watersheds from the stormwater impacts of land development is critical for maintaining the water quality of streams and lakes. Careful planning, design and long-term maintenance activities are needed both during and long after construction is complete.

There are many reasons why watersheds need protection when land development occurs:

Soil Erosion Increases

  • When development occurs, soils are exposed to wind and water action that can lead to soil erosion and sedimentation of surface waters like streams, ponds and lakes. 
  • Increased impervious surfaces prevent infiltration of rainwater, creating larger volumes and velocities of stormwater runoff. This contributes to stream bank erosion and sedimentation.

Loss of Water Quality Buffers and Floodplains

  • If development removes vegetated buffers and/or impacts floodplains, this can cause erosion of stream banks and loss of open space that is essential for water quality, flood risk reduction and support of wildlife habitat.

Pollution Sources Increase

  • Development and urbanization result in more pollutants such as bacteria, metals, oil, and nutrients on impervious surfaces (i.e., pavement, rooftops) that then flow through stormwater drainage systems into surface waters such as streams and lakes. 

To learn about the programs that protect watersheds, please see the following: