Yes. Rainwater collection is fully legal in Mississippi, with no state limits on how much you can collect from your roof.
What Mississippi law says
Mississippi places no state-level restrictions on residential rainwater harvesting. You can install as many barrels or cisterns as your property supports, and no permit or registration is required. No state restrictions. As always, check for HOA covenants or local ordinances before installing a larger system.
How much water a Mississippi roof can collect
Mississippi averages about 59 inches of rain per year. On a typical 1,200 square foot roof at 85% collection efficiency, that works out to roughly 37,500 gallons a year currently running into your storm drain. A single one-inch storm delivers about 635 gallons, enough to fill 13 standard 50-gallon barrels.
Average annual rainfall in Mississippi.
Gallons per year from a typical 1,200 sq ft roof.
Approximate annual value at municipal water rates.
Your roof and rainfall will differ; run your exact numbers in the rainwater calculator.
The right setup for Mississippi’s climate
At roughly 59 inches of rain a year, Mississippi is a wet-climate state; your barrel will refill constantly. Prioritize a sealed, mosquito-proof design and plan the overflow path. A 50-gallon barrel with a diverter that returns excess water to the downspout is the right call.
Rain Wizard 50 + Diverter Kit, reviewed against our independent testing criteria. See all six models side by side.
Common questions
Is it illegal to collect rainwater in Mississippi?
Do I need a permit for a rain barrel in Mississippi?
Does Mississippi offer incentives for rainwater harvesting?
Sources
- Rainplan, 50-State Rainwater Collection Guide (2026)
- State statutes and water agency guidance for Mississippi
- NOAA National Centers for Environmental Information, annual precipitation normals
- US EPA WaterSense, Outdoor Water Use fact sheet
Educational content, not legal advice. Laws change; confirm current rules with your state water agency.