RoofRainYield

Beverly, MA rainwater: 38,167 gallons off a roof

Beverly, MA: gallons off the roof each year

38,167gallons a year

That is a 1,500 sq ft asphalt roof under Beverly, MA's normal 48.0 inches of rain, about 795 gallons for every inch that falls.

In Beverly, 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 Beverly station (2.2 mi away). Beverly, MA ranks 43rd wettest of the 58 cities covered in Massachusetts.

Month by month in Beverly

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.742,973
Feb3.612,869
Mar4.643,688
Apr4.203,33819
May3.472,758110
Jun3.993,17145
Jul3.432,726115
Aug3.362,671123
Sep3.823,03666
Oct4.993,966
Nov3.983,163
Dec4.793,807

Oct is the wettest month (4.99 in, 3,966 gal off the roof); Aug the driest (3.36 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 Beverly

Best fit: one 55-gallon barrel, which delivers about 373 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 Beverly's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal37336,533
110 gal37336,533
165 gal37336,533
275 gal37336,533
550 gal37336,533
1,000 gal37336,533
1,500 gal37336,533
2,500 gal37336,533
5,000 gal37336,533

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