Stormwater Control Measures (SCMs) reduce the amount of polluted stormwater that enter our creeks and streams.
Types of Stormwater Control Measures
Bioretention basin (or rain garden)
A bioretention basin, or rain garden is a hole filled with native plantings and special soil mix. It collects and slows stormwater runoff and removes pollutants.
Pervious Pavement
Permeable pavement allows stormwater runoff to drain through the pavement into the soil below.
Wet Retention Ponds
Wet retention ponds can consist of a combination of a permanent deep water pool and a shallow marsh. These ponds allow pollutants to settle out of the water, encourage natural microbial activity that cleans the water, and reduces the overall amount of stormwater runoff.
Dry Detention Ponds
Dry detention ponds temporarily store and slowly release stormwater runoff, and prevent downstream flooding. Sediment (soil), nutrients, heavy metals, and other pollutants settle out in the pond.
Proprietary Devices or Water Quality Units
%20-%20small.jpg)
Water quality units filter pollutants out of stormwater runoff and release the treated water to the drainage system. The structures have limited pollutant storage and require frequent maintenance.
Grassy Swale
Grassy swales reduce and slow down the flow of stormwater runoff as well as filter out some pollutants.
Maintaining Your Stormwater Control Measure
Property owners are responsible for inspecting and maintaining SCMs on their property.
Inspections are required at least annually and maintenance is required as needed. A maintenance and inspection document for your SCM is included with your property deed. These documents are available through the Metro Nashville Register of Deeds.
More information including the location, type, and, in some cases, maintenance information for your SCM can be found on the Metro Planning Parcel Viewer. For instructions on how to use the Parcel Viewer, download our “How to Find Your SCMs” guide.
For a list of certified SCM inspectors, visit the Tennessee Stormwater Management website SCM training page and click the "certification list" tab. For a list of companies that maintain SCMs, download "Water Quality SCM Maintenance Companies".
Reporting Your Annual Inspection
Some property owners are also required to report their annual inspection to Metro Water Services . This is based on when the grading permit requiring your SCM(s) was issued.
To find your grading permit issue year, download and follow our “How to Find Your SCMs" guide. The year will be the first four digits of your SCM’s Project ID. Then use the chart below to identify what you need to report.
| Grading Permit Issue Year |
Reporting Requirement |
| Pre mid-2007 |
No Annual Report |
| Mid 2007 – 2013 |
Owner submits Annual Report by July 1 of each year |
| 2014 – present |
- Owner submits Annual Report by July 1 of each year
- All SCMs require inspection by a qualified professional every 5 years |
Your annual report must include:
- completed SCM checklist for each SCM on your property
- Photographs documenting any changes to your SCM
- Photographs documenting completion of any maintenance work
Your annual report should be emailed to mws.scm@nashville.gov or mailed to:
Metro Water Services
Stormwater-NPDES
1607-A County Hospital Road
Nashville, TN 37218
Questions?
More information about Metro Water Services regulation of SCMs is available in our Stormwater Management Manual under “Stormwater Control Measure (SCM) Maintenance Document”.
If you have questions about your SCM, call Metro Water Services at 615-880-2420 or email us at mws.scm@nashville.gov.