RoofRainYield

Cañon City, CO rainwater: 10,547 gallons off a roof

How much rain a roof in Cañon City, CO collects

10,547gallons a year

That is a 1,500 sq ft asphalt roof under Cañon City, CO's normal 13.3 inches of rain, about 795 gallons for every inch that falls.

Cañon City, CO has gaps between storms long enough to drain a single barrel. Around 110 gallons of storage catches most of what is worth catching.

Rainfall: NOAA 1991-2020 climate normals, the Canon City 1.3 Ene station (0.6 mi away). Cañon City, CO ranks 49th wettest of the 53 cities covered in Colorado.

Month by month in Cañon City

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan0.43342
Feb0.44350
Mar0.80636
Apr1.741,383325
May1.831,454314
Jun0.69548456
Jul2.792,218194
Aug2.001,590293
Sep0.97771421
Oct0.72572453
Nov0.37294
Dec0.49389

Jul is the wettest month (2.79 in, 2,218 gal off the roof); Nov the driest (0.37 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 Cañon City?

Best fit: 2 linked 55-gallon barrels, which delivers about 1,769 gallons to the garden in a normal year (72.0% of its need).

Colorado caps storage at 110 gallons, below the 165 gallons that would pay off here. The table marks sizes over the cap.

If you set one up, link barrels with a short hose at the base so they fill and drain together, and check the overflow points away from the house.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal1,1078,975
110 gal1,7698,313
165 gal (over cap)2,0628,020
275 gal (over cap)2,2317,851
550 gal (over cap)2,2317,851
1,000 gal (over cap)2,2317,851
1,500 gal (over cap)2,2317,851
2,500 gal (over cap)2,2317,851
5,000 gal (over cap)2,2317,851

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