Emergency stabilization and permanent remediation for sinkholes, voids, and ground collapse. Municipal, NYSDOT, and commercial contracts. Karst bedrock, infrastructure-caused voids, buried debris. $20K-$300K+.
Backwell is a heavy civil excavation contractor based at 4830 W Seneca Turnpike in Syracuse. We handle sinkhole investigation, emergency stabilization, void grouting, and full permanent repair for municipal, state, and commercial clients across Central New York. When a road opens up, a parking lot swallows a vehicle, or a building slab drops overnight, we mobilize fast , we run our own excavators, dozers, dump trucks, and pump equipment, and we don't wait on subcontractors to start the work.
Our sinkhole projects range from $20,000 for small emergency stabilizations up to $300,000 or more for complex remediation involving bedrock grouting, engineered fill, and structural restoration. Typical clients include town highway departments, NYSDOT Region 3, county DPWs, commercial property managers, homeowner associations with failing infrastructure, and insurance carriers handling collapse claims.
Emergency line: (315) 400-2654 , For active collapses or safety hazards we mobilize the same day.
CNY sits on a geological setup that makes ground failure more common here than most people realize. Large portions of southern Onondaga County, Madison County, and the areas around Cazenovia, Chittenango, and Jamesville sit on Onondaga Limestone and Syracuse Formation bedrock , classic karst terrain. When rainwater percolates through soil with dissolved carbon dioxide, it slowly eats cavities into the limestone over thousands of years. Eventually the soil cap above a cavity fails and the surface drops out.
On top of the natural karst problem, the region has two other major sinkhole drivers: aging infrastructure and historical mining. Syracuse has cast iron water mains and brick sanitary sewers dating to the 1800s. When a joint fails or a pipe collapses, the flowing water carves voids in the bedding and native soil until the surface caves in. I-81, I-690, and Route 481 have all had documented sinkhole incidents tied to failing stormwater infrastructure. Parts of Tully, Fabius, and the Onondaga Valley also have historical salt mining and gypsum mine subsidence that continues to produce surface collapses decades after the mines closed.
True geological sinkholes where limestone solution cavities have opened beneath a soil cap. Most common in southern Onondaga County, throughout Madison County, and in pockets of Cayuga and Cortland counties. Karst sinkholes usually require bedrock grouting, deep engineered fill, and long-term monitoring because the underlying cavity system can extend well beyond the visible failure.
The most common sinkhole we see in the Syracuse metro. A failing sanitary sewer, storm drain, or water main erodes bedding material and carves a void that eventually reaches the surface. Repair requires locating and replacing the failed utility, then backfilling with engineered fill or flowable fill in lifts. See our underground utility services.
Soil slowly ravels into a pre-existing subsurface void until the surface can no longer support its own weight. These often appear overnight as round depressions in yards, fields, or roadway shoulders. Full repair means excavating to the bottom of the void, treating the cavity, and backfilling with compacted structural fill.
CNY has a long industrial and urban history. Old cisterns, buried fuel tanks, collapsed basements, filled-in dumps, demolished structures buried in place, and construction debris fill all create long-term settlement problems. When the organic matter decomposes or voids collapse, the surface drops. We see these routinely under parking lots and in redeveloped urban parcels around Syracuse, Auburn, and Utica.
Every sinkhole repair starts with understanding what's actually under the ground before we move a single bucket of dirt. Guessing on this work is how contractors end up repairing the same hole twice.
For karst and large void projects we coordinate pressure grouting of bedrock cavities , typically cement-based or polyurethane resin grout pumped under pressure to fill the cavity and stabilize the surrounding rock mass before structural fill goes back in. Our rock excavation crews handle the excavation-to-bedrock work in-house.
| Scope | Typical Cost Range |
|---|---|
| Emergency stabilization + perimeter safety (24-hour mobilization) | $20,000 – $45,000 |
| GPR / geophysical survey coordination | $6,000 – $18,000 |
| Geotechnical boring program (3-6 holes) | $12,000 – $30,000 |
| Small sinkhole repair (under 10 ft diameter, shallow) | $25,000 – $55,000 |
| Medium sinkhole repair (10-25 ft, to bedrock) | $60,000 – $140,000 |
| Large sinkhole repair (over 25 ft, deep void, roadway) | $150,000 – $300,000+ |
| Bedrock pressure grouting (karst cavities) | $18,000 – $80,000 |
| Engineered structural fill & compaction | $35 – $85 per CY installed |
| Surface restoration (asphalt, concrete, landscape) | $8,000 – $60,000 |
For full remediation of a major roadway or commercial site collapse, expect total project costs in the $150,000 to $300,000+ range once emergency response, investigation, bedrock grouting, structural fill, and surface restoration are all included.
We handle sinkhole and ground collapse work for town and city highway departments, NYSDOT Region 3, Onondaga County DPW, Madison County, commercial property owners and asset managers, retail and industrial site operators, homeowner associations with private road or drainage failures, insurance carriers and their adjusters, civil engineering firms coordinating repair design, and structural engineers dealing with building foundation subsidence.
Comfortable working under municipal bid procedures, NYSDOT emergency contracts, insurance scope-of-loss documentation, and standard AIA commercial contracts. For insurance claim work we provide detailed documentation adjusters need , photos, elevations, void measurements, material tickets, and daily logs.
It depends on the policy. Standard commercial property insurance usually excludes "earth movement," which includes most natural sinkholes, but many carriers offer a sinkhole rider or collapse endorsement. Policies that cover sudden and accidental collapse from infrastructure failure (like a failed water main that erodes a void under a parking lot) are more likely to pay. For municipalities and DOT, sinkhole repair is typically funded through emergency maintenance budgets or state infrastructure programs.
We coordinate ground-penetrating radar (GPR) and electrical resistivity surveys with licensed geophysical firms. GPR uses radio wave reflections to map subsurface voids, loose soil, and bedrock contours to depths of 15-30 feet depending on soil type. For deeper investigations we combine GPR with geotechnical borings.
Higher-risk areas in CNY include southern Onondaga County (Jamesville, Lafayette, Tully), most of Madison County, and any urban parcel with aging cast iron water mains or brick sanitary sewers , especially in Syracuse, Auburn, Oswego, and Utica. Warning signs include unexplained soft spots in lawns or pavement, circular depressions, doors or windows suddenly sticking, cracks in foundation walls that weren't there last year, and trees tilting for no apparent reason.
Emergency stabilization: 24-72 hours. Small infrastructure-driven sinkhole: 1-2 weeks once permits are in place. Medium roadway collapse: 3-6 weeks including investigation, grouting, fill, and restoration. Large karst-related projects with engineered grouting programs: 2-4 months from first call to final surface restoration.
Yes, but it requires coordination with a structural engineer and usually some form of temporary shoring or underpinning before the void is excavated. We've worked on subsidence cases under commercial slabs, parking structures, and warehouse foundations. See our grading and site restoration work.
For active collapses or safety hazards, call (315) 400-2654 directly. For planned remediation work, send site photos, any existing engineering reports, and the scope of the problem.
We handle sinkhole repair as part of a broader infrastructure and site work practice that includes mass excavation, rock excavation, site grading, and storm drainage. Read our 5.0-star Google reviews.
If your project involves rental property, multi-family, or commercial real estate in Central New York, our sister company RenPro Property Management can take over operations after the dirt work is done. RenPro manages office buildings, retail space, and industrial properties. More about our network.