Duluth, MN Landscaping Rules: Rainwater Harvesting (2026)

3 of the Unified Development Chapter (Chapter 50) lists rainwater harvesting tanks among the accessory features, alongside clotheslines, play equipment, trash containers, and odor-controlled composting bins, that are permitted only in side and rear yards, not front yards, when sited as accessory to a principal structure. That is a more favorable standard than the Chapter's general accessory-structure rule, which otherwise keeps accessory structures at least 3 feet from side lot lines, 5 feet from rear lot lines, and away from any facade facing the street.

Accessory rain gardens get an even broader allowance in the same table: they are permitted in all yards, front, side, and rear alike, reflecting the city's preference for on-site stormwater infiltration over piping runoff straight to the street. Separately, in the sewer chapter, Section 43-31(a) addresses roof drainage design directly: downspouts connected to roof gutters cannot discharge water within two feet of the building foundation, or run parallel to the property within five feet of the property line, unless the downspout is instead connected to a rain barrel with a minimum capacity of 35 gallons.

That rain-barrel exception effectively rewards residents who capture roof runoff rather than discharge it near the foundation or lot line, and it sits alongside the city's inflow-and-infiltration enforcement program, which inspects building sewers and can order homeowners to disconnect improper drainage connections.