Illinois Rainwater Harvesting Law: Statewide Landscaping Rules Rules (2026)

Key Facts

Governing Act: 415 ILCS 56
Plumbing Code: 225 ILCS 320
Regulator: IDPH and CDB
Potable Use: Generally prohibited

Full Breakdown

The Illinois Rainwater Harvesting Manual Act (415 ILCS 56) requires the Capital Development Board, in consultation with the Department of Public Health, to adopt a manual setting design standards for non-potable rainwater harvesting systems. Systems must comply with the Illinois Plumbing Code (225 ILCS 320), which is administered statewide by IDPH and preempts conflicting local plumbing rules. Cross-connection controls and backflow prevention are mandatory.

Violations & Penalties

Plumbing Code violations are Class A misdemeanors and may carry civil penalties up to $1,000 per day, plus revocation of plumbing licenses by IDPH.

Frequently Asked Questions

Can Illinois cities ban rainwater harvesting?

No. State law explicitly authorizes harvesting for non-potable use, and the Illinois Plumbing Code preempts conflicting municipal plumbing ordinances administered by IDPH.

Can harvested rainwater be used for drinking?

No. The Illinois Plumbing Code restricts harvested rainwater to non-potable uses such as irrigation and toilet flushing unless treated to drinking water standards.

Illinois Rainwater Harvesting Statewide Plumbing Standards

Key Facts

Full Breakdown

Violations & Penalties

Frequently Asked Questions

Sources

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