RoofRainYield

East Grand Rapids, MI rainwater: 31,474 gallons off a roof

How much rain a roof in East Grand Rapids, MI collects

31,474gallons a year

That is a 1,500 sq ft asphalt roof under East Grand Rapids, MI's normal 39.6 inches of rain, about 795 gallons for every inch that falls.

In East Grand Rapids, 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 E Grand Rapids station (0.7 mi away). East Grand Rapids, MI ranks 6th wettest of the 90 cities covered in Michigan.

Month by month in East Grand Rapids

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.722,162
Feb2.111,677
Mar2.602,066
Apr4.103,25931
May4.403,497
Jun4.033,20340
Jul3.312,631130
Aug3.052,424162
Sep3.522,798103
Oct3.702,94181
Nov3.302,623
Dec2.762,194

May is the wettest month (4.40 in, 3,497 gal off the roof); Feb the driest (2.11 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Barrel or cistern in East Grand Rapids?

Best fit: one 55-gallon barrel, which delivers about 425 gallons to the garden in a normal year (77.7% 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 East Grand Rapids's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal42529,685
110 gal42529,685
165 gal42529,685
275 gal42529,685
550 gal42529,685
1,000 gal42529,685
1,500 gal42529,685
2,500 gal42529,685
5,000 gal42529,685

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