Szabo Construction Co Inc
Postville, IAAllamakee County
demolition, excavation, grading, hauling trucking, pond water management, septic systems
Photo: Jatakuck at English Wikipedia (CC BY-SA 3.0) via Wikimedia Commons
Allamakee County, IA Contractor directory
Excavation contractors in Allamakee County, IA
11 verified excavating and site work contractors serving Allamakee County.
County excavation guide
Ground conditions and project requirements in Allamakee County
Use this local research to understand soil, seasonal constraints, permits, and jobsite logistics before choosing a contractor.
Skip to 11 contractorsSoil Regime ProfileEPA Ecoregion 46, 47, 52 (Central Irregular Plains, Western Corn Belt Plains, Driftless Area)
Iowa Driftless Bluffs, Loess Hills & Southern Prairies
Dominant Soil Order: Mollisols / Alfisols / Inceptisols
Parent Material: Loess over Pre-Illinoian Glacial Drift and Paleozoic Carbonate Bedrock in the Un-glaciated Northeast
Iowa outside the Des Moines Lobe is older ground: the unglaciated Driftless corner in the northeast, the sculpted Loess Hills along the Missouri, and the dissected southern prairies. The Driftless counties (Allamakee, Clayton, Winneshiek, Fayette, Dubuque, Jackson) carry Paleozoic limestone and dolomite close to the surface: shallow bedrock on 20-40 percent of land, sinkhole karst in the uplands, and slopes over 15 percent on 20-40 percent of the terrain, so bench cuts, contour septic lines, and rock excavation are routine. The Loess Hills (Woodbury, Monona, Harrison) are thick wind-blown silt on steep ridges: cut banks stand nearly vertical but erode fast, and grading work means erosion control on every slope. Southern Iowa adds the shallowest bedrock in the state (Mississippian limestone within a few feet in Lucas, Monroe, Appanoose) and tighter clay subsoils. Across all three sub-regions, shrink-swell stays moderate and hydric soils concentrate in river bottoms; the recurring site questions are rock depth, slope stability, and karst.
Geographic Footprint:Iowa's older ground (the Driftless northeast, the Loess Hills, and the southern tier) trades the prairie flat for bluffs, ridges and rock: limestone near the surface in the Driftless, deep erodible loess on the western ridge tops, and shallow Mississippian bedrock across the southern counties. Rock depth and slope drive the bids here.
Geotechnical Baseline
Physical Ground Conditions & Soil Properties
Shallow Bedrock (<50 in)
9.4%of county land area
Deep soil mantle; rock refusal rare for standard basement or trench cuts.
High Shrink-Swell Clay
0.0%expansive soil
Low volumetric expansion risk in native subgrade.
Median Water Table Depth
18inches from surface
Shallow water table; active dewatering or sumps needed for deep trenching.
Hydric / Wetland Soils
3.9%hydric coverage
Indicates poor natural drainage and potential jurisdictional wetland pockets.
Steep Terrain (Slope >15%)
38.6%of terrain
Mountain/hilly terrain; terracing, benching, and tracked haulers frequent.
Septic Severe Limitations
94.1%severe rate
High rate of conventional drainfield limitations; engineered or drip systems often required.
Dominant Soil Textures:Silt loamSilty clay loamLoamy sand
Surface Stones / Boulders: 15.2% coverage
Compliance & Permitting
Earthwork Regulations & Permit Thresholds
Stormwater & Erosion Control
Iowa DNR NPDES General Permit No. 2 (Storm Water Discharge Associated with Industrial Activity for Construction Activities), effective Mar 1 2023 to Feb 29 2028; covers construction disturbing one acre or more, and smaller sites that are part of a larger common plan that will ultimately disturb one acre or more. Outstanding Iowa Waters watersheds require an individual permit.
Administers NPDES stormwater discharge coverage for land-disturbing construction activities.
State Threshold:1.00 Acre
Local Threshold:Follows state
Onsite Wastewater & Utilities
Allamakee County Environmental Health
Jurisdiction over septic tank permits, soil evaluation perk tests, and drainfield sizing.
Housing on Septic:55.0%
Soil Evaluation:Percolation test or soil analysis (soil boring about 6 ft) by a licensed engineer or approved septic contractor; 3 ft separation to limiting layer
811 One-Call Requirements
Iowa One Call (811)
Mandatory notice window: 48 hours prior to mechanized earthwork (excluding weekends and legal holidays).
Licensing & Clearing Permits
Weather & Ecology
Seasonal Constraints & Clearing Windows
Frozen Ground Days
90days / year
Typical days with sub-freezing soil conditions affecting digging.
Wet Season Months
May, June, July, August
Peak precipitation window requiring sediment traps and soil aeration.
Supply Chain & Hazards
Logistics, Aggregate Sources & Geohazards
Aggregate & Material Supply
Mccabe Quarry
Nearest active quarry: 8 miles haul distance.(19 active crushed stone/sand operations within 50 miles).
Flood & Hazard Overlay
FEMA 100-Yr Flood:7.7%(100% NFHL digital map coverage)
NWI Wetlands:7.7%jurisdictional coverage
Karst Terrain & Sinkhole Risk: Low
68.2% of county underlain by soluble carbonate rock formations.
HUC8 Primary Watersheds:Coon-Yellow, Upper Iowa, Turkey
Public conservation land: 9.0% (USGS PAD-US).
Area-specific FAQ
Do I need to call before digging in Allamakee County?
Yes. You should contact Iowa One Call at least 2 working days before any digging so underground lines can be marked.
How deep do footings need to be in Iowa?
In Iowa, footings typically need to extend below the frost line, which is around 48 inches here. A local contractor will confirm the code requirement for your site.
Verified local listings
Excavation contractors serving Allamakee County
11 verified listings
NE Iowa Excavating
Lansing, IAAllamakee County
excavation, grading, pond water management, retaining walls, trenching underground
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