Post-Construction / Permanent Stormwater Management

Refer to Section 4.2.5. of the MS4 Permit for the WQTV Table and additional information related to post-construction/permanent stormwater management in New Development and Redevelopment.  For general design purposes, the Metro Nashville LID spreadsheet is not an accepted design tool in Hendersonville.

Infiltration-Based SCMs

Use of infiltration-based SCMs will require supporting documentation from infiltration testing.

• Infiltration Testing Requirements

Hendersonville Standards for Manufactured Treatment Devices (MTD)

As required in MS4 Permit Section 4.2.5.2., TSS removal rates for MTDs must be evaluated using industry-wide standards.  TSS removal rates for other SCMs must be from published reference literature.  The City accepts TSS removal rates as certified by the New Jersey Department of Environmental Protection (NJDEP)/New Jersey Corporation for Advanced Technology (NJCAT) and Washington State's Department of Ecology TAPE Program.

Permanent SCM Certification

Within 90 days of the installation of a Permanent Stormwater control measure, a Professional Engineer or Registered Landscape Architect, preferably the site designer, shall complete the Permanent Stormwater Control Measure Certification Form.

• Permanent Stormwater Control Measure Certification Form

Post-Construction Inspection and Maintenance Requirements

Every new development/redevelopment in the City of Hendersonville is required to complete a Stormwater Inspection and Maintenance Agreement (IMA)/Long-Term Maintenance Plan (LTMP).  Prior to release of the Land Disturbance Surety the property owners will be required to record the IMA/LTMP, in its entirety, with the Sumner County Register of Deeds and provide a copy of the recorded document to the City. The property owner is responsible for inspecting and maintaining SCMs in perpetuity.  At a minimum, property owners are required to inspect SCMs annually, or as described in the Long-Term Maintenance Plan.  Regular inspections shall be performed by a licensed engineer, a licensed landscape architect, or by a person with an active Tennessee Stormwater Management Training SCM Inspection and Maintenance Course Certification.  At least once every five (5) years, the property owner shall have a licensed engineer or landscape architect perform a comprehensive inspection of all SCMs.  All inspection documents shall be submitted with the annual report on July 1 of each year.  

• Hendersonville Inspection and Maintenance Agreement/Long-Term Maintenance Plan Form
• Hendersonville Inspection and Maintenance Checklists
• Example Long-Term Maintenance Plan
• Annual Report Checklist for Inspection and Maintenance of Private Stormwater Management Facilities
• Post-Construction Stormwater Inspection Vendors
• Tennessee Stormwater Management SCM Inspection and Maintenance Course Certification List (Required for all SCMs after 9/10/2024)
• Best Practices for the Maintenance of Detention and Bioretention Areas - 5/14/2025

Public Works As-Built Requirements

The City requires submittal of as-built plans prior to the release of the land disturbance surety.   Except for detention ponds, most of the specified items would likely not need full topographic survey, but verification that as designed and as-built conditions match.  Any changes should be noted on the plans and plans should be stamped as-built.  For detention ponds, you will need to provide as-built contours and certify that the ponds meet the storage requirements (post-development outfall is less than pre-development).  

• Public Works As-Built Requirements

Storm Sewer System Mapping Requirements 

The City is required to map the storm sewer system and as part of this requirement the City will require developers to provide data to continue mapping the storm sewer system.  The Hendersonville Stormwater Asset Management Workbook must be completed and submitted with the As Built plans.  Below is a link to download the workbook.  The City has provided examples and notes to aid in completion of the workbook.

• Hendersonville Stormwater Asset Management Workbook

For residential development, the entire storm system must be included in the workbook.  For commercial/non-residential development, all permanent stormwater control measures, connections to the MS4, outfalls to the MS4, and installation of storm infrastructure in the right-of-way must be included in the workbook.