Arizona explicitly authorizes rainwater harvesting under state policy and provides income tax credits for systems, preventing municipalities from banning residential collection of rooftop or runoff rainwater.
ARS 45-105 articulates state policy supporting rainwater harvesting and stormwater conservation. ARS 43-1090.01 grants individual income tax credits up to 25% of system cost (capped at $1,000) for water conservation systems installed in primary residences. Several Arizona cities, including Tucson, actually mandate harvesting for commercial landscape water use. Because the state actively promotes harvesting, blanket municipal prohibitions are not permitted, although cities may regulate cistern setbacks and overflow safety.
There are no state penalties for harvesting. Local building or plumbing code violations for unpermitted large cisterns may result in correction notices or modest civil fines.
See how Lake Havasu City's rainwater harvesting rules stack up against other locations.
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