Iowa permits rainwater harvesting without specific ownership restrictions, treating it as unregulated for most residential uses like rain barrels. Water rights primarily follow surface drainage laws rather than prior appropriation, emphasizing natural flow over capture. Conservation focuses on stormwater management to prevent runoff issues.
Rainwater Ownership
Property owners can collect rainwater from rooftops or yards freely, with no state laws claiming it belongs to the government or downstream users. This differs from riparian rights states; Iowa’s approach assumes landowners control precipitation on their land unless local ordinances apply, such as in urban stormwater zones. No permits are needed for small systems under typical home use.
Drainage Rights
Under Iowa Code §468.621, uphill landowners (dominant estates) have a right to drain surface water naturally onto lower lands (servient estates), which must accept it without obstruction. Harvesting can’t unreasonably alter this flow or damage neighbors; tiling or ditches require county approval if crossing properties. Servient owners can seek remedies if flow increases unnaturally cause harm.​
Conservation Laws
Rainwater harvesting promotes conservation via programs like rainscaping, encouraged for gardens and barrels to reduce flooding. Stormwater rules under the Iowa Stormwater Management Manual require developments to manage runoff, often incentivizing capture over discharge. No statewide potable use bans exist, but filtration is advised for drinking.
Violations like blocking natural drainage lead to civil liability, not criminal penalties.​
