Rainwater, storm water and surface waters

Background

Florida’s abundant rainfall provides an excellent opportunity for nonpotable irrigation water supply. With the implementation of the revised Florida Department of Environmental Protection (DEP) Stormwater Quality rule (Chapter 62-347, Florida Administrative Code), using storm water for irrigation will become a viable option for both residential and commercial development.

Requirements and certification

Permanent irrigation is supplied by rainwater, storm water or surface water that meets the program criteria. The backup supply cannot be from a potable source. Irrigation is supplied by a rainfall harvesting system (designed in accordance with Tampa Bay Water BMP manual).

When any alternate source is used for irrigation, it is the responsibility of the applicant to confirm that the maintenance schedule requirement of the irrigation system can be met with the alternate source.

For additional recommendations on cistern design and installation, the applicant should refer to:

• Rainwater Harvesting with Cisterns for Landscape Irrigation from Tampa Bay Water
• IAPMO Green Plumbing Supplement
• International Green Construction Code
• National Sanitation Foundation

For the Florida Water Star Inspector to evaluate the cistern’s capacity in relation to the irrigation system’s requirements, applicants must submit the following information:

• Formulas used for the sizing calculation in accordance with Tampa Bay Water BMP manual
• A detailed design drawing
• Irrigation system precipitation rates (each zone)
• Irrigation controller scheduling information

The Inspector will review details of the design and sizing of the cistern. Utility-supplied potable water cannot be used as backup for rainfall on any cistern. The Inspector may seek input from Florida Water Star administrators in determining the point allocation for this practice.

When using storm water for irrigation, the Inspector must confirm that the applicant has determined that the stormwater pond can be used for irrigation purposes and treatment will not be diminished.