Portage, IN rainwater: 32,420 gallons off a roof
Portage, IN: gallons off the roof each year
32,420gallons a year
That is a 1,500 sq ft asphalt roof under Portage, IN's normal 40.8 inches of rain, about 795 gallons for every inch that falls.
In Portage, IN 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 Gary 4.8 Ene station (4.4 mi away). Portage, IN ranks 64th wettest of the 88 cities covered in Indiana.
Month by month in Portage
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 2.29 | 1,820 | |
| Feb | 2.40 | 1,908 | |
| Mar | 2.72 | 2,162 | |
| Apr | 4.08 | 3,243 | 34 |
| May | 4.33 | 3,442 | 2 |
| Jun | 4.53 | 3,600 | |
| Jul | 3.93 | 3,124 | 52 |
| Aug | 4.01 | 3,187 | 42 |
| Sep | 3.81 | 3,028 | 67 |
| Oct | 3.52 | 2,798 | 103 |
| Nov | 2.92 | 2,321 | |
| Dec | 2.25 | 1,788 |
Jun is the wettest month (4.53 in, 3,600 gal off the roof); Dec the driest (2.25 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
What size rain barrel for Portage
Best fit: one 55-gallon barrel, which delivers about 237 gallons to the garden in a normal year (78.6% 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 Portage's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 237 | 31,028 |
| 110 gal | 237 | 31,028 |
| 165 gal | 237 | 31,028 |
| 275 gal | 237 | 31,028 |
| 550 gal | 237 | 31,028 |
| 1,000 gal | 237 | 31,028 |
| 1,500 gal | 237 | 31,028 |
| 2,500 gal | 237 | 31,028 |
| 5,000 gal | 237 | 31,028 |
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 Indiana?
No statewide rainwater harvesting regulations; check county for local incentives
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