Maryland treats rainwater as a resource that property owners can freely collect and own for personal use, with no statewide restrictions on harvesting. The state actively encourages it through stormwater management guidelines and local incentives rather than imposing water rights claims on rainfall.​
Harvesting Regulations
Rainwater systems fall under the Maryland Plumbing Code (Chapter 13), which governs non-potable collection, storage, and distribution but permits residential use without special permits. Cities like Baltimore and counties such as Montgomery offer rebates—up to $250 for rain barrels or $500 for cisterns—to promote conservation.​
Conservation Laws
State stormwater rules require developers to manage runoff on-site, often incorporating harvesting to reduce flooding and pollution, but private owners face no ownership limits. Potable use needs treatment compliance, though it’s unregulated for non-drinking purposes.
SOURCES
[1](https://www.ntotank.com/blog/rainwater-harvesting-laws-regulations-and-rights-by-us-state)
[2](https://pioneerwatertanksamerica.com/is-it-illegal-to-collect-rainwater-in-your-state/)
[3](https://mde.maryland.gov/programs/Water/waterconservation/Pages/state_laws.aspx)
[4](https://4perfectwater.com/blog/rainwater-harvesting-laws)
[5](https://www.montgomerycountymd.gov/DEP/property-care/rainscapes/water-harvesting.html)
