Yes, rainwater collection is legal in New Hampshire, but compliance hinges on adherence to state water rights laws and local ordinances. The New Hampshire Department of Environmental Services (NHDES) permits non-potable uses under specific conditions, while potable systems require additional health department approvals. Recent 2026 guidance emphasizes stormwater management compliance for commercial systems exceeding 2,500 gallons.
Key Regulations for Rainwater Collection in New Hampshire
- Water Rights Compliance: Collection must not interfere with existing riparian or prior appropriation rights, per RSA 473:1. Unauthorized diversion risks civil penalties under NHDES enforcement.
- Potable System Restrictions: Systems intended for drinking require NHDES and local health department certification, including filtration meeting EPA standards for lead and microbial contaminants.
- Stormwater Management: Commercial installations over 2,500 gallons must align with NHDES Stormwater Management Manual (2026 update), ensuring peak flow control and erosion prevention.
Local municipalities, such as the City of Manchester’s Water Works, may impose additional permitting for structural installations. Exemptions exist for single-family residential systems under 2,500 gallons, provided they do not alter natural drainage patterns. Always verify with the NHDES Small Systems Unit and municipal authorities before implementation to avoid enforcement actions.