Meriden, CT rainwater: 35,655 gallons off a roof

How much rain a roof in Meriden, CT collects

35,655gallons a year

That is a 1,500 sq ft asphalt roof under Meriden, CT's normal 44.9 inches of rain, about 795 gallons for every inch that falls.

In Meriden, CT 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 Meriden Markham Muni Ap station (2.5 mi away). Meriden, CT ranks 15th wettest of the 21 cities covered in Connecticut.

Month by month in Meriden

Month	Rain (in)	Off the roof (gal)	Garden shortfall (gal)
Jan	3.05	2,424
Feb	2.93	2,329
Mar	4.05	3,219
Apr	4.13	3,283	27
May	3.48	2,766	108
Jun	4.05	3,219	37
Jul	3.38	2,686	121
Aug	3.54	2,814	101
Sep	4.28	3,402	9
Oct	4.49	3,569
Nov	3.36	2,671
Dec	4.12	3,275

Oct is the wettest month (4.49 in, 3,569 gal off the roof); Feb the driest (2.93 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 Meriden

Best fit: one 55-gallon barrel, which delivers about 320 gallons to the garden in a normal year (79.2% 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 Meriden's roof water will pass straight through it.

Tank	Water used (gal/yr)	Spills over (gal/yr)
55 gal	320	34,240
110 gal	320	34,240
165 gal	320	34,240
275 gal	320	34,240
550 gal	320	34,240
1,000 gal	320	34,240
1,500 gal	320	34,240
2,500 gal	320	34,240
5,000 gal	320	34,240

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 Connecticut?

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