Rainwater falling on private property belongs to the landowner under prior appropriation doctrine, but collection must not reduce natural runoff or interfere with downstream water rights. The Office of the State Engineer permits residential and commercial rooftop harvesting without permits for domestic purposes, provided it mimics pre-development flow.​
Conservation Laws
Harvested rainwater qualifies as conservation, supporting landscape irrigation or indoor non-drinking uses, but cannot be sold or diverted off-site without approval. Cisterns and barrels face no strict size limits for small-scale use, though large systems may need engineering review to ensure no groundwater impact.​
Key Restrictions
Prohibitions apply to using harvested water for potable supply or commercial appropriation, aligning with broader water rights administered by the State Engineer. Local incentives in areas like Los Alamos promote greywater and rainwater systems for sustainability. Violations risk permit denials or fines under water diversion statutes.
SOURCES
[1](https://www.ntotank.com/blog/rainwater-harvesting-laws-regulations-and-rights-by-us-state)
[2](https://streamdynamics.us/rainwater-harvesting-policy-and-legal-issues)
[3](https://worldwaterreserve.com/is-it-illegal-to-collect-rainwater/)
[4](https://www.reddit.com/r/legaladviceofftopic/comments/vbs9ep/what_is_rainwater_harvesting_law_like_in_new/)
[5](https://www.ose.nm.gov/WUC/wuc_policy.php)
