Delta County, CO Roof Snow Load - Case Study Area
Why doesn't Delta County have a snow load number?
Delta County sits in the mountain-west terrain where ASCE 7-22 §7.2 itself declines to give a contour figure - elevation changes too fast over short distances there for one number per county to mean anything. The code requires a site-specific study for a building here, not a look-up.
Delta County, FIPS 08029, is home to 32,215 people - one of 386 US counties ASCE 7 itself routes around a map figure for.
Delta County at a glance
- Population32,215
- Annual snowfall, NOAA normal21.5 in.
- FIPS08029
Typical snowfall in Delta County, CO
NOAA's 30-year normal for Delta County: 21.5 in. of snow a year, from the MONTROSE #2, CO US station. That station is far enough away (26 mi) that local snowfall - especially at a different elevation or near a lake - can run noticeably higher or lower than this figure. (fresh vs. packed vs. ice explains why.)
What this Delta County figure assumes
This is a county-level reference figure for a typical heated home built to Risk Category II (ordinary residential), on a partially exposed lot - the assumptions ASCE 7-22 itself treats as the default case. A steeper roof, a fully exposed hilltop lot, an unheated structure, or a higher risk category all change the actual number.
Delta County's permit office wants an address-specific figure, not this county average - the ASCE 7 Hazard Tool is free, takes under a minute, and outputs a PDF most reviewers accept. (How this figure is calculated.)