Fenton, MI rainwater: 27,405 gallons off a roof

Fenton, MI: gallons off the roof each year

27,405gallons a year

That is a 1,500 sq ft asphalt roof under Fenton, MI's normal 34.5 inches of rain, about 795 gallons for every inch that falls.

In Fenton, MI 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 Linden Wwtp station (4.5 mi away). Fenton, MI ranks 50th wettest of the 90 cities covered in Michigan.

Month by month in Fenton

Month	Rain (in)	Off the roof (gal)	Garden shortfall (gal)
Jan	2.37	1,884
Feb	1.87	1,486
Mar	2.03	1,613
Apr	3.21	2,551	142
May	3.83	3,044	65
Jun	3.34	2,655	126
Jul	3.51	2,790	105
Aug	3.31	2,631	130
Sep	3.08	2,448	158
Oct	3.30	2,623	131
Nov	2.53	2,011
Dec	2.10	1,669

May is the wettest month (3.83 in, 3,044 gal off the roof); Feb the driest (1.87 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

What size rain barrel for Fenton

Best fit: one 55-gallon barrel, which delivers about 679 gallons to the garden in a normal year (79.3% of its need).

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

Tank	Water used (gal/yr)	Spills over (gal/yr)
55 gal	679	25,661
110 gal	679	25,661
165 gal	679	25,661
275 gal	679	25,661
550 gal	679	25,661
1,000 gal	679	25,661
1,500 gal	679	25,661
2,500 gal	679	25,661
5,000 gal	679	25,661

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 Michigan?

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