Yes, rainwater collection is legal in Tennessee, but its legality hinges on compliance with state and local water rights laws, particularly the Reasonable Use Doctrine under Tennessee Code Annotated § 69-8-101. While no statewide ban exists, the Tennessee Department of Environment and Conservation (TDEC) monitors systems that may impact groundwater or surface water supplies. Local municipalities, such as Nashville’s Metro Water Services, impose additional permitting requirements for systems exceeding 500 gallons, aligning with the 2026 updates to the Tennessee Water Quality Control Act.
Key Regulations for Rainwater Collection in Tennessee
- Permitting Thresholds: Systems storing over 500 gallons require approval from the TDEC or local water authorities, per Rule 1200-4-3-.05(3). Small residential systems (under 500 gallons) typically avoid formal permitting but must prevent cross-connections with potable water.
- Water Rights Compliance: Collection must not impair downstream users’ rights under the Reasonable Use Doctrine, which prioritizes agricultural and municipal withdrawals. Violations may trigger enforcement under T.C.A. § 69-8-104.
- Quality Standards: Collected rainwater intended for non-potable uses (e.g., irrigation) must adhere to TDEC’s Stormwater Pollution Prevention Guidelines, prohibiting contamination from roof materials or debris. Potable use requires secondary treatment and health department approval.