Expansive Soil in Yukon-Koyukuk Census Area, AK
Does Yukon-Koyukuk Census Area, AK have expansive soil? Mostly not: the dominant shrink-swell rating for Yukon-Koyukuk Census Area, AK is Low, with 100% of the county's mapped soil acres in the Low class.
Soil class breakdown for Yukon-Koyukuk Census Area
What a Low rating means for a slab foundation
Soils in this class contain little expansive clay. Moisture changes cause minimal volume change, so shrink-swell movement is rarely the main cause of foundation problems here. Slabs can still settle for other reasons, including poor drainage, plumbing leaks under the slab, tree roots drawing moisture, and soil that was not compacted well during construction.
This is a county-level rating built from USDA soil survey data, not a parcel-level geotechnical assessment. Soils change from lot to lot; a geotechnical engineer or foundation professional can assess the ground under your specific property.
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Methodology and sources
This rating is computed from USDA NRCS SSURGO soil survey data
:
for each soil component we take the maximum linear extensibility percent
(lep_r) among horizons starting within 0 to 100 cm of the surface, apply the
NRCS National Soil Survey Handbook Part 618 class limits (Low under 3 percent, Moderate 3
to under 6, High 6 to under 9, Very High 9 and above), assign each map unit the class
holding the plurality of component percent, and sum map unit acres per class across the
county, excluding unmapped and water areas.
- Data source: USDA NRCS SSURGO via Soil Data Access
- Class limits: NRCS National Soil Survey Handbook, Part 618
- Survey coverage: 97% of county map acres
- Computed: 2026-07-05
- Note: max lep_r over horizons with hzdept_r<100cm (major components only), comppct_r plurality per mapunit, county rollup by muaoverlap.areaovacres, class limits NSSH Part 618, shares are fractions of rated acres
Full methodology · All Alaska counties · Look up another ZIP
FAQ
Does Yukon-Koyukuk Census Area, AK have expansive soil?
Mostly not: the dominant shrink-swell rating for Yukon-Koyukuk Census Area, AK is Low, with 100% of the county's mapped soil acres in the Low class.
What does a Low rating mean for a slab foundation?
Soils in this class contain little expansive clay. Moisture changes cause minimal volume change, so shrink-swell movement is rarely the main cause of foundation problems here. Slabs can still settle for other reasons, including poor drainage, plumbing leaks under the slab, tree roots drawing moisture, and soil that was not compacted well during construction.
Is this a parcel-level soil report?
No. This is a county-level rollup of USDA NRCS SSURGO soil survey data for Yukon-Koyukuk Census Area, AK. Soils vary lot to lot, so a geotechnical engineer or foundation professional should assess your specific property before you make repair decisions.
How much does foundation repair cost near Yukon-Koyukuk Census Area?
Pricing depends on the repair method and how far the movement has progressed, from sealing a single crack to installing piers. SlabLocal publishes city-level foundation repair cost guides with sourced ranges for cities across Alaska.