Burlington, VT rainwater: 29,829 gallons off a roof

Rainwater from a roof in Burlington, VT

29,829gallons a year

That is a 1,500 sq ft asphalt roof under Burlington, VT's normal 37.5 inches of rain, about 795 gallons for every inch that falls.

In Burlington, VT 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 Burlington Intl Ap station (4.7 mi away). Burlington, VT ranks 3rd wettest of the 4 cities covered in Vermont.

Month by month in Burlington

Month	Rain (in)	Off the roof (gal)	Garden shortfall (gal)
Jan	2.13	1,693
Feb	1.77	1,407
Mar	2.24	1,780
Apr	3.07	2,440	160
May	3.76	2,988	74
Jun	4.26	3,386	11
Jul	4.06	3,227	36
Aug	3.54	2,814	101
Sep	3.67	2,917	85
Oct	3.83	3,044	65
Nov	2.70	2,146
Dec	2.50	1,987

Jun is the wettest month (4.26 in, 3,386 gal off the roof); Feb the driest (1.77 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 Burlington?

Best fit: one 55-gallon barrel, which delivers about 398 gallons to the garden in a normal year (74.9% 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 Burlington's roof water will pass straight through it.

Tank	Water used (gal/yr)	Spills over (gal/yr)
55 gal	398	28,171
110 gal	398	28,171
165 gal	398	28,171
275 gal	398	28,171
550 gal	398	28,171
1,000 gal	398	28,171
1,500 gal	398	28,171
2,500 gal	398	28,171
5,000 gal	398	28,171

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 Vermont?

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