Sterling, CO rainwater: 13,655 gallons off a roof
Sterling, CO: gallons off the roof each year
13,655gallons a year
That is a 1,500 sq ft asphalt roof under Sterling, CO's normal 17.2 inches of rain, about 795 gallons for every inch that falls.
In Sterling, CO 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 Sterling 1.5 Sse station (1.0 mi away). Sterling, CO ranks 25th wettest of the 53 cities covered in Colorado.
Month by month in Sterling
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.30 | 238 | |
| Feb | 0.44 | 350 | |
| Mar | 0.73 | 580 | |
| Apr | 1.70 | 1,351 | 330 |
| May | 2.94 | 2,337 | 176 |
| Jun | 2.64 | 2,098 | 213 |
| Jul | 2.84 | 2,257 | 188 |
| Aug | 2.13 | 1,693 | 277 |
| Sep | 1.31 | 1,041 | 379 |
| Oct | 1.19 | 946 | 394 |
| Nov | 0.63 | 501 | |
| Dec | 0.33 | 262 |
May is the wettest month (2.94 in, 2,337 gal off the roof); Jan the driest (0.30 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 Sterling
Best fit: 2 linked 55-gallon barrels, which delivers about 1,689 gallons to the garden in a normal year (86.3% 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 Sterling's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 1,276 | 11,838 |
| 110 gal | 1,689 | 11,426 |
| 165 gal (over cap) | 1,709 | 11,405 |
| 275 gal (over cap) | 1,709 | 11,405 |
| 550 gal (over cap) | 1,709 | 11,405 |
| 1,000 gal (over cap) | 1,709 | 11,405 |
| 1,500 gal (over cap) | 1,709 | 11,405 |
| 2,500 gal (over cap) | 1,709 | 11,405 |
| 5,000 gal (over cap) | 1,709 | 11,405 |
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 Colorado?
Most households may use rain barrels: a maximum of two rain barrels with a combined storage of 110 gallons or less per household, rooftop runoff only, used outdoors on the same property (HB16-1005). Larger rooftop collection only for qualifying well-permit holders (SB09-080) or pilot projects (HB09-1129).
Checked against the current source on 2026-11-06. Source