RoofRainYield

Fitchburg, MA rainwater: 39,422 gallons off a roof

Rainwater from a roof in Fitchburg, MA

39,422gallons a year

That is a 1,500 sq ft asphalt roof under Fitchburg, MA's normal 49.6 inches of rain, about 795 gallons for every inch that falls.

In Fitchburg, MA 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 Fitchburg Coop station (1.2 mi away). Fitchburg, MA ranks 25th wettest of the 58 cities covered in Massachusetts.

Month by month in Fitchburg

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.522,798
Feb3.302,623
Mar4.353,457
Apr4.193,33020
May3.702,94181
Jun4.273,39410
Jul3.692,93382
Aug4.283,4029
Sep4.253,37812
Oct5.314,220
Nov3.883,084
Dec4.863,863

Oct is the wettest month (5.31 in, 4,220 gal off the roof); Feb the driest (3.30 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 Fitchburg

Best fit: one 55-gallon barrel, which delivers about 163 gallons to the garden in a normal year (76.0% of its need).

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

TankWater used (gal/yr)Spills over (gal/yr)
55 gal16338,044
110 gal16338,044
165 gal16338,044
275 gal16338,044
550 gal16338,044
1,000 gal16338,044
1,500 gal16338,044
2,500 gal16338,044
5,000 gal16338,044

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 Massachusetts?

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