RoofRainYield

Fraser, MI rainwater: 26,864 gallons off a roof

Fraser, MI: gallons off the roof each year

26,864gallons a year

That is a 1,500 sq ft asphalt roof under Fraser, MI's normal 33.8 inches of rain, about 795 gallons for every inch that falls.

In Fraser, 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 Roseville 1.7 Ene station (2.7 mi away). Fraser, MI ranks 68th wettest of the 90 cities covered in Michigan.

Month by month in Fraser

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.361,876
Feb1.811,439
Mar2.271,804
Apr2.992,376170
May3.272,599135
Jun3.162,512148
Jul3.692,93382
Aug3.592,85395
Sep3.182,527146
Oct2.632,090214
Nov2.542,019
Dec2.311,836

Jul is the wettest month (3.69 in, 2,933 gal off the roof); Feb the driest (1.81 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 Fraser

Best fit: one 55-gallon barrel, which delivers about 773 gallons to the garden in a normal year (78.1% 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 Fraser's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal77324,967
110 gal77324,967
165 gal77324,967
275 gal77324,967
550 gal77324,967
1,000 gal77324,967
1,500 gal77324,967
2,500 gal77324,967
5,000 gal77324,967

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