Laconia, NH rainwater: 36,251 gallons off a roof

How much rain a roof in Laconia, NH collects

36,251gallons a year

That is a 1,500 sq ft asphalt roof under Laconia, NH's normal 45.6 inches of rain, about 795 gallons for every inch that falls.

In Laconia, NH 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 Lakeport 2 station (2.1 mi away). Laconia, NH ranks 6th wettest of the 11 cities covered in New Hampshire.

Month by month in Laconia

Month	Rain (in)	Off the roof (gal)	Garden shortfall (gal)
Jan	3.08	2,448
Feb	2.88	2,289
Mar	3.39	2,694
Apr	3.65	2,901	87
May	3.47	2,758	110
Jun	4.44	3,529
Jul	4.61	3,664
Aug	3.89	3,092	57
Sep	3.77	2,996	72
Oct	4.83	3,839
Nov	3.68	2,925
Dec	3.92	3,116

Oct is the wettest month (4.83 in, 3,839 gal off the roof); Feb the driest (2.88 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 Laconia?

Best fit: one 55-gallon barrel, which delivers about 252 gallons to the garden in a normal year (77.1% 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 Laconia's roof water will pass straight through it.

Tank	Water used (gal/yr)	Spills over (gal/yr)
55 gal	252	34,709
110 gal	252	34,709
165 gal	252	34,709
275 gal	252	34,709
550 gal	252	34,709
1,000 gal	252	34,709
1,500 gal	252	34,709
2,500 gal	252	34,709
5,000 gal	252	34,709

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 New Hampshire?

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