Installing a new automatic irrigation system.

Yes, it is required by Florida law.

Statute: Florida Statute § 373.62 mandates: "Any person who operates an automatic landscape irrigation system shall properly install, maintain, and operate technology that inhibits or interrupts operation of the system during periods of sufficient moisture."

Code Enforcement: The Florida Building Code, Plumbing (FPC) Section 607.3 and Florida Fire Prevention Code (NFPA 1, Section 18.4.5) adopt this requirement. Most local municipalities (e.g., South Florida Water Management District, St. Johns River WMD) enforce this via irrigation permits and final inspections.

Practical Requirements:

1. Device Type: Must be a rain sensor (expansion disk or tipping bucket) or soil moisture sensor (SMS). "Smart" ET-based controllers qualify if they have a rain shut-off input connected to a physical sensor.
2. Placement: Mount in an unobstructed location (open sky, no tree cover/overhangs) per manufacturer specs—typically on a fence post or eave, 5–10 ft above grade.
3. Wiring: Connect to the controller’s "SEN" or "RS" terminals (normally closed circuit). If the controller lacks dedicated terminals, you must install a sensor isolation relay (e.g., Rain Bird RSDBEx) to avoid frying the board.
4. Setting: Set shutdown threshold to ¼" to ½" rainfall (adjust per local Water Management District rules).

Penalty: Non-compliance can result in code violations, fines ($50–$500/day), and liability for water waste. Many utilities deny rebates or mandate retrofits at point-of-sale.

Bottom line: Install a wired rain sensor (e.g., Hunter Mini-Clik, Rain Bird RSD-BEx) or SMS. It’s $30–$60 in parts, 15 minutes labor, and legally non-negotiable.

In Florida, a rain sensor is required by law for new automatic irrigation systems under certain conditions.

According to Florida Statute § 373.62 and enforced by local water management districts (e.g., South Florida Water Management District, St. Johns River Water Management District), all new automatic irrigation systems installed after May 1, 1991, must include a rain sensor device or switch that overrides the irrigation cycle when adequate rainfall has occurred.

This applies to:

• Residential and commercial properties
• Systems connected to potable water supplies
• New installations (not retrofits, unless required by local ordinance during permitting)

The sensor must be:

• Properly installed (unobstructed by eaves, trees, or overhangs)
• Functional and maintained
• Capable of interrupting irrigation after ¼ inch of rainfall (varies slightly by district)

Exception: Some localities may allow exemptions for systems using reclaimed water or drip irrigation, but these are rare and jurisdiction-specific.

Bottom line: It’s not just a good idea — it’s state law for new installations. Skipping it risks fines, failed inspections, and water waste. Always verify with your local water management district or building department for exact requirements, as enforcement and minor details can vary by county.

Install it — it saves water, money, and keeps you compliant.