How much does excavation cost in NH?

It depends entirely on the job, because excavation covers everything from a small drainage trench to a full septic install. As a rough Lakes Region map: a curtain drain on an accessible lot runs $2,500 to $5,000, a new gravel driveway runs $3,500 to $22,000 by length and grade, and a conventional septic system runs $18,000 to $30,000 installed, with advanced treatment systems reaching $60,000. I quote by the job after a free site visit, not by the hour, because the dig you can see from the road is rarely the dig once we open the ground.

Why do excavation quotes vary so much between contractors?

Scope, access, and ledge. One quote may include drainage and final grading while another stops at the dig. A lot with granite ledge a foot down is a completely different job than the same lot with eight feet of clean soil. And a fully insured operator with workers' comp costs more than an uninsured pickup-and-excavator outfit, which is exactly the difference you want to pay for. A quote that is half of everyone else's almost always has a reason, and it is usually one of those three.

Do you charge by the hour or by the job?

By the job, with a flat written quote after I walk the site. Homeowners ask for an hourly rate because it feels safer, but it actually puts the risk on you: if I hit ledge or the soil is worse than expected, the meter just keeps running. A flat quote puts that risk on me, where it belongs. The only time I move to an hourly rate is open-ended work where neither of us can scope it up front, like a brush-hogging job on a lot too dense to predict.

What is the biggest hidden cost in NH excavation?

Granite ledge. Bedrock sits anywhere from a foot to twenty feet down across the Lakes Region, and if it turns up in a driveway run or a leach field you are into breaking or routing around it, which adds $1,000 to $5,000 on a driveway and more on a septic. The second one is septic feasibility on raw land: if the lot fails its perc test, an engineered or mound system can add $20,000 to $40,000 over a conventional install. I probe for both before I write a number on a long run.

Is the estimate free?

Yes. I come out, walk the property, look at access, soil, slope, and what is actually in the way, and write you a flat-rate quote at no charge. If the honest answer is that you do not need the work, or that a cheaper fix solves the problem, I will tell you that too. I would rather not sell you a $5,000 drain than sell you one that does not fix your wet basement.

Excavation Cost in NH (2026): Real Prices by Job Type

The first question on almost every call I get is some version of "what's this going to run me?" It's a fair question, and I wish I could answer it in one number. The trouble is that "excavation" is the broadest word in this trade. It covers a fifty-foot drainage trench on a flat suburban lot and a full septic system on a hillside camp lot near Newfound Lake, and those two jobs are not within shouting distance of each other on price. Anybody who gives you a firm number before they've walked your property is either guessing or padding.

So instead of a useless one-size range, let me walk you through what the actual jobs cost in the Lakes Region, sorted by the kind of work. These are the numbers I quote in Bristol, Franklin, Hill, Plymouth, and the towns around the lakes. If you read to the bottom, you'll also know the two things that quietly turn a reasonable budget into a painful one, so you can spot them before they spot you.

Why I quote by the job, not the hour

Homeowners often ask for my hourly rate, because an hourly number feels safer and easier to compare. I understand the instinct, but it actually works against you. If I quote you by the hour and then hit a seam of granite ledge a foot down, the meter just keeps running while I deal with it, and the cost lands on you. A flat quote puts that risk on me, where it belongs. I walk the site, read what the ground is likely doing, build the surprises into one number, and that's the price.

The only time I move to an hourly rate is genuinely open-ended work that neither of us can scope up front, like brush-hogging a lot so overgrown I can't see what's under it until I'm in it. For everything with a defined start and finish, you get a flat written quote. When you're comparing me to another contractor, make sure you're comparing the same thing: a flat quote that includes cleanup and grading is not the same as an hourly number that stops at the dig.

Gravel driveways: $3,500 to $22,000

This is the most common excavation job I do, and the range is wide because length, grade, and drainage swing it hard. Built right (topsoil stripped, a compacted base, three layers of stone, a crown to shed water), here's where Lakes Region driveways land:

Short residential, around 60 feet, flat, good soil, no culvert: $3,500 to $5,500. A suburban lot or a short camp driveway.
Medium, around 120 feet with one culvert crossing: $6,500 to $11,000. The typical Lakes Region residential job. Width (10 feet versus 14 feet), culvert size, and whether the site needs fabric all move the number.
Long or uphill rural, around 300 feet with grade management and proper drainage: $14,000 to $22,000. Camp roads and lake-access driveways. A steep run needs more base stone, deeper swales, and sometimes waterbars to keep it from washing out.

If the route crosses ledge, breaking through it adds roughly $1,000 to $5,000 depending on how much rock is in the way. I probe for it before quoting a long run. The full breakdown, including why the cheap driveway fails in its second mud season, is in my gravel driveway guide for the NH Lakes Region.

Septic systems: the big one

A septic install is the most expensive excavation job most homeowners will ever pay for, and the one they understand the least. Here's the honest map:

Conventional gravity system (tank, distribution box, leach field, decent soil, reasonable access): $12,000 to $25,000 installed. Most Franklin, Hill, and Bristol jobs sit in here.
Typical residential replacement: most land in the $18,000 to $30,000 range once you account for permitting, design, and demo of the old system.
Pump system (gravity isn't an option, needs a lift pump): add $2,500 to $5,000 over conventional.
Advanced treatment (required on tight lots, near protected water, or with poor soils): $30,000 to $60,000.
Tank-only replacement (the field still has useful life): $5,000 to $10,000.

Ledge, long pipe runs, or a hillside field add another $2,000 to $6,000 on top of whichever system you're building. About $2,500 to $4,000 of a typical install is the designer and town permitting before I ever turn a bucket of dirt. I broke the whole thing down, including how to read a quote line by line, in the NH septic install guide.

Drainage: the cheapest problem to fix early

Water in the wrong place is what eventually wrecks driveways, foundations, and septic fields, so a drainage fix is often the smartest money on this whole list. A curtain drain (an intercepting trench that catches groundwater before it reaches your basement or your driveway) runs like this:

Short run, 50 to 100 feet, accessible lot, good soil, no ledge: $2,500 to $5,000. The typical fix for a wet basement on a small village or suburban lot.
Medium, 100 to 200 feet, some access challenges or partial ledge: $4,500 to $9,000. Where most Lakes Region residential jobs land.
Long, 200 to 400 feet, serious ledge, tight access, or a far-off outlet: $8,000 to $18,000 or more.

As I tell people who call about a wet basement: I can usually tell on the visit whether you're looking at a $1,500 fix or a $15,000 one, and sometimes the right answer is gutters and a regrade, not a drain at all. The full walkthrough, plus the four mistakes that make new drains fail, is in the curtain drain installation guide.

Land clearing and brush work: priced by the day

Clearing is the one category I usually price by time rather than a flat lump, because density matters more than acreage. A quarter-acre of wall-to-wall saplings can cost more than a half-acre that's mostly open. Rough guide:

Open field, light scrub: about half a day.
Mixed brush and saplings under 3 inches: roughly a full day per acre.
Dense growth with stumps to pull and trees up to 6 to 8 inches: two to three days per acre.

For straight brush-hogging open growth (goldenrod, meadowsweet, raspberry, small saplings under four inches), I'm typically $300 to $600 per acre; denser lots move to an hourly rate. Burning brush on-site instead of chipping and hauling saves real money where the town allows it. Details are on the lot clearing and brush-hogging pages. Anything bigger than 8-inch trunk diameter usually goes through tree work as its own scope.

Tree work that comes with the dig

A lot of excavation starts with taking trees down to make room for a driveway, a leach field, or a building pad. Most residential tree removals in the Lakes Region land between $300 and $2,500, with crane jobs near a structure reaching $4,500. Diameter, height, access, and whether the wood is live or brittle drive it. Because the equipment is already on site for the dig, bundling the tree work into the same job usually costs less than calling someone separately. I put the real per-tree math, including why a dead ash costs more than a live one, in what tree removal actually costs in NH.

The two things that blow up a budget

Across all of the work above, the same two surprises are responsible for almost every quote that comes in higher than a homeowner expected.

Granite ledge. Bedrock sits anywhere from a foot to twenty feet down across this region, and you don't always know it's there until a bucket finds it. When ledge turns up in a driveway run or a leach field, you're into breaking it or routing around it, which is the single most common reason one quote on a lot is thousands higher than another. A contractor who probes for ledge before quoting is protecting you from a change order later, not padding the number.

Septic feasibility on raw land. If you're building on an undeveloped lot, the whole project hinges on whether the soil percolates. A failed perc test isn't always the end of the road, but the engineered or mound system that gets you out of it can add $20,000 to $40,000 over a conventional install. And before the driveway itself even starts, a new culvert, headwall, and town or state driveway permit can run $2,000 to $8,000. If you're shopping land, my guide to buying raw land in the Lakes Region covers what to check before you sign.

“The cheapest quote and the most expensive quote are often for the exact same job. The difference is who probed for ledge before writing the number down.”

What I do on a site visit

When I come out, I'm reading the same handful of variables every time: access for my equipment, what the soil and slope are doing, where water wants to go, and whether ledge is likely in the dig. I'll walk it with you, tell you honestly what the job takes, and write a flat-rate quote. If something genuinely can't be known until we open the ground (buried surprises happen), I flag it up front rather than spring a change order on you halfway through.

I don't charge for the visit, and I'd rather tell you a cheaper fix solves your problem than sell you work you don't need. If you've got a project you're trying to budget, the only way to get a real number is to have someone who does this for a living look at the actual ground. You can see the full range of what I do on the excavation service page, or just reach out and I'll come walk it with you.