Charlotte Water

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Backflow Prevention Construction Guidelines for Industrial and Commercial Construction Projects

All industrial and commercial customers are required by ordinance to install and maintain backflow prevention devices at every water service connection to Charlotte Water. This includes domestic, irrigation, fire line services, and swimming pool meters.

Before beginning any construction project, industrial and commercial customers must submit construction plans to Mecklenburg County Land Use and Environmental Services. There, Charlotte Water will evaluate your plans and inform you of the requirements.

  • A detailed list of plan submittal requirements
  • Land Use & Environmental Services Agency. LUESA includes code enforcement and reference desk information.
  • Commonly Requested Documents, Information & Requirements (AutoCAD Downloads included)
  • Depending on the type of backflow installation required, the installer must comply with certain construction specifications. These address materials, clearances, enclosures, drainage and inspections. 
  • When the backflow prevention device is installed, call Charlotte Water at 704-391-5188 to request an inspection. A Charlotte Water approved and certified tester must test the device upon installation and annually thereafter.

Questions, contact us by email or call 311 or 704-336-7600.

Another resource is the Carolinas Chapter of American Backflow Prevention Association.

Click below for the Backflow design specifications.

Reduced Pressure Principle Assemblies  (Full set of pdfs

  • 1 1/2" - 2" Reduced Pressure Principle Assembly (RP) Above Ground, Standard Detail # 1 (dwg file or pdf)   
  • 2 1/2" - 12" Reduced Pressure Principle Assembly (RP) Above Ground, Standard Detail # 2 (dwg file or pdf
  • 3/4" - 2" Reduced Pressure Principle Assembly (RP) Indoor, Standard Detail # 8  (dwg file or pdf)
  • 2 1/2" - 12" Reduced Pressure Principle Assembly (RP) Indoor, Standard Detail # 9 (dwg file or pdf)
  • 3/4" & 1" Reduced Pressure Principle Assembly (RP) Above Ground, Standard Detail # 13  (dwg file or pdf)
  • Testcock Locations, Standard Detail # 12 (dwg file or pdf)

Double Check Valve Assemblies

  • 1 1/2" - 2" Double Check Valve Assembly (DC) Above Ground, Standard Detail # 3 (dwg file or pdf)
  • 2 1/2" - 12" Double Check Valve Assembly (DC) Above Ground, Standard Detail # 4  (dwg file or pdf)
  • 3/4" & 1" Double Check Valve Assembly (DC) Below Ground Vault, Standard Detail # 5 (dwg file or pdf)
  • 1 1/2" - 2" Double Check Valve Assembly (DC) Below Ground Vault, Standard Detail # 6  (dwg file or pdf)
  • 2 1/2" - 12" Double Check Valve Assembly (DC) Below Ground Vault, Standard Detail # 7  (dwg file or pdf)
  • 3/4" - 2" Double Check Valve Assembly (DC) Indoor, Standard Detail # 10 (dwg file or pdf)
  • 2 1/2" - 12" Double Check Valve Assembly (DC) Indoor, Standard Detail # 11 (dwg file or pdf)
  • 3/4" & 1" Double Check Valve Assembly (DC) Above Ground, Standard Detail #14  (dwg file or pdf​) 
  • Testcock Locations, Standard Detail # 12  (dwg file or pdf)