RoofRainYield

Freehold, NJ rainwater: 38,604 gallons off a roof

How much rain a roof in Freehold, NJ collects

38,604gallons a year

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

In Freehold, NJ 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 Freehold-Marlboro station (3.9 mi away). Freehold, NJ ranks 72nd wettest of the 116 cities covered in New Jersey.

Month by month in Freehold

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.873,076
Feb3.102,464
Mar4.203,338
Apr3.833,04465
May3.813,02867
Jun4.443,529
Jul4.653,696
Aug4.133,28327
Sep4.193,33020
Oct4.133,28327
Nov3.542,814
Dec4.683,720

Dec is the wettest month (4.68 in, 3,720 gal off the roof); Feb the driest (3.10 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 Freehold?

Best fit: one 55-gallon barrel, which delivers about 158 gallons to the garden in a normal year (76.3% 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 Freehold's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal15837,201
110 gal15837,201
165 gal15837,201
275 gal15837,201
550 gal15837,201
1,000 gal15837,201
1,500 gal15837,201
2,500 gal15837,201
5,000 gal15837,201

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 Jersey?

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