RoofRainYield

Gulfport, MS rainwater: 49,930 gallons off a roof

How much rain a roof in Gulfport, MS collects

49,930gallons a year

That is a 1,500 sq ft asphalt roof under Gulfport, MS's normal 62.8 inches of rain, about 795 gallons for every inch that falls.

In Gulfport, MS a single barrel does most of the work. Storms come often enough that a small tank refills before it runs dry, and a bigger one would mostly sit full.

Rainfall: NOAA 1991-2020 climate normals, the Gulfport - Biloxi Ap station (0.9 mi away). Gulfport, MS ranks 9th wettest of the 41 cities covered in Mississippi.

Month by month in Gulfport

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan4.873,871
Feb4.443,529
Mar5.224,149
Apr5.514,379
May4.743,767
Jun6.895,476
Jul7.215,731
Aug6.535,190
Sep5.184,117
Oct3.712,94980
Nov4.033,203
Dec4.493,569

Jul is the wettest month (7.21 in, 5,731 gal off the roof); Oct the driest (3.71 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Which tank size is worth it in Gulfport

Best fit: one 55-gallon barrel, which delivers about 69 gallons to the garden in a normal year (86.5% of its need).

If you buy one, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Gulfport's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal6948,735
110 gal6948,735
165 gal6948,735
275 gal6948,735
550 gal6948,735
1,000 gal6948,735
1,500 gal6948,735
2,500 gal6948,735
5,000 gal6948,735

Simulated storm by storm through a normal year using the station's count of days with 0.1 in or more of rain each month.

Is rainwater collection legal in Mississippi?

No rainwater harvesting regulations

From the 2015 (Pacific Northwest National Laboratory report 24347); not yet re-checked against current law, so check with your state water agency before building anything large. Source