Knoxville, TN Landscaping Rules: Rainwater Harvesting (2026)

Knoxville's Appendix B (Zoning Code) treats rainwater harvesting as an accessory feature regulated under Article 7, the Form-Based Code Districts covering the South Waterfront District (subdistricts SW1 through SW7, including Old Sevier and Scottish Pike) and the Cumberland Avenue District. Two general rules under Sec. 7.0.3, General Rules of Applicability, govern every subdistrict. First, under Setback Encroachments, Sec. 7.0.3.E.2.b: a rainwater collection or harvesting system under 10 feet in height, grouped with solar panels and wind turbines, 'may encroach into a required rear setback, provided that such extension is at least 5 feet from the vertical plane of any lot line.' Second, under Height Encroachments, Sec. 7.0.3.I.2.f, the same class of accessory structure may rise above the district's maximum building height by up to 6 feet without a variance.

Inside the SW1 Old Sevier and Scottish Pike subdistrict specifically, Sec. 7.1.3.B's development standards checklist, item 8 ("External Elements"), adds a design duty: trash and recycling storage, external mechanical and electrical units, and rain barrels must be integrated with building design or screened and concealed from view from the public street and riverwalk. Identical language repeats at the corresponding item in Sec. 7.1.3.C through 7.1.3.H for the SW2 through SW7 subdistricts, so the screening duty runs district-wide across South Waterfront, not just at Old Sevier.

Outside the South Waterfront and Cumberland Avenue form-based code districts, these specific rainwater-harvesting provisions do not apply; other Knoxville zoning districts use Article 10's general accessory-structure and encroachment standards instead, and Sec. 7.1.1 confirms Article 7's requirements run 'to all development within the South Waterfront District.'