RoofRainYield

Palmer Town, MA rainwater: 38,643 gallons off a roof

Palmer Town, MA: gallons off the roof each year

38,643gallons a year

That is a 1,500 sq ft asphalt roof under Palmer Town, MA's normal 48.6 inches of rain, about 795 gallons for every inch that falls.

In Palmer Town, 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 Ware station (5.9 mi away). Palmer Town, MA ranks 38th wettest of the 58 cities covered in Massachusetts.

Month by month in Palmer Town

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.632,885
Feb3.242,575
Mar4.073,235
Apr3.913,10855
May3.622,87791
Jun4.353,457
Jul4.323,4344
Aug4.603,656
Sep4.033,20340
Oct4.923,910
Nov3.642,893
Dec4.293,410

Oct is the wettest month (4.92 in, 3,910 gal off the roof); Feb the driest (3.24 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Which tank size is worth it in Palmer Town

Best fit: one 55-gallon barrel, which delivers about 144 gallons to the garden in a normal year (76.0% 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 Palmer Town's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal14437,179
110 gal14437,179
165 gal14437,179
275 gal14437,179
550 gal14437,179
1,000 gal14437,179
1,500 gal14437,179
2,500 gal14437,179
5,000 gal14437,179

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