Walworth County, SD Roof Snow Load - 35 psf
Walworth County, SD roof snow load, translated
A typical heated home in Walworth County is designed to carry 35 pounds per square foot of snow on its roof, per ASCE 7-22.
On a roof that means 77 in. of fresh snow, 28 in. once it packs down, or 7 in. of solid ice - three very different piles for the same load. A load this size is a serious structural matter; pre-modern-code homes and low-slope or flat-roofed sections are the ones most worth an inspection.
Walworth County, SD: quick facts
- Design roof snow load35 psf
- Ground snow load, ASCE 7 map50 psf
- National rank#199 of 2,758
- South Dakota rank#10 of 65
- Population5,270
- Annual snowfall, NOAA normal33.4 in.
- FIPS46129
Where Walworth County ranks
#10 of 65 South Dakota counties by design load, top 7% of 2,758 nationally - that's Walworth County's spot. That's 6.8 psf above South Dakota's own county-average design load of 28.2 psf.
FIPS 46129, population 5,270, centered near 45.4276°N 100.0279°W. ASCE 7's underlying ground snow load here is 50 psf before the code's exposure and importance factors bring it to the 35 psf design figure above.
Walworth County: average annual snowfall
Walworth County sees about 33.4 in. of snow most winters, per the SELBY, SD US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Walworth County's figure
The figure above assumes the case ASCE 7-22 treats as typical: a heated, ordinary-occupancy home on a partially exposed site. Change any of those - exposure, heating, roof pitch, occupancy category - and the real design number moves.
A building permit needs the number at your exact address, not the county average - the free ASCE 7 Hazard Tool returns that from your coordinates in about a minute and produces a PDF a plan reviewer will accept. Details: the calculation guide.