Superior, CO rainwater: 14,752 gallons off a roof
Superior, CO: gallons off the roof each year
14,752gallons a year
That is a 1,500 sq ft asphalt roof under Superior, CO's normal 18.6 inches of rain, about 795 gallons for every inch that falls.
In Superior, 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 Boulder 5.4 Ese station (3.9 mi away). Superior, CO ranks 13th wettest of the 53 cities covered in Colorado.
Month by month in Superior
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.72 | 572 | |
| Feb | 0.90 | 715 | |
| Mar | 1.67 | 1,327 | |
| Apr | 2.67 | 2,122 | 209 |
| May | 2.90 | 2,305 | 181 |
| Jun | 1.77 | 1,407 | 322 |
| Jul | 1.81 | 1,439 | 317 |
| Aug | 1.51 | 1,200 | 354 |
| Sep | 1.64 | 1,303 | 338 |
| Oct | 1.43 | 1,137 | 364 |
| Nov | 0.83 | 660 | |
| Dec | 0.71 | 564 |
May is the wettest month (2.90 in, 2,305 gal off the roof); Dec the driest (0.71 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 Superior
Best fit: 2 linked 55-gallon barrels, which delivers about 1,802 gallons to the garden in a normal year (86.4% 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 Superior's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 1,362 | 12,760 |
| 110 gal | 1,802 | 12,319 |
| 165 gal (over cap) | 1,806 | 12,316 |
| 275 gal (over cap) | 1,806 | 12,316 |
| 550 gal (over cap) | 1,806 | 12,316 |
| 1,000 gal (over cap) | 1,806 | 12,316 |
| 1,500 gal (over cap) | 1,806 | 12,316 |
| 2,500 gal (over cap) | 1,806 | 12,316 |
| 5,000 gal (over cap) | 1,806 | 12,316 |
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