Every concrete project that touches the ground — a new driveway, a patio, footings for a wall — involves excavation, and California law treats that excavation the same whether it's a utility trench or a homeowner's backyard slab. Government Code § 4216.2 requires notifying the regional utility-locating service before you dig, with a specific timing window and a real penalty for skipping it: hitting a buried gas, electric, or fiber line.
The rule, in plain terms
Before excavating, notify USA North 811 — the regional notification center covering Salinas, Monterey, Seaside, Marina, and the rest of Northern and Central California — at least two working days before you plan to dig, and not more than 14 calendar days ahead. The day you call doesn't count toward the two-day minimum. The resulting ticket is valid for 28 days from issuance. USA North 811's own site states plainly that the service is for "professional excavators, homeowners, DIYers, agricultural operators or anyone who needs to perform any digging activities" — there's no small-project or homeowner exemption.
Step by step
- Mark or describe the area to be excavated. Before you contact USA North 811, outline the area where digging will happen — white paint, stakes, or flags along the planned footprint of the driveway, patio, or footing work.
- Call 811 or submit online at least two working days ahead. Dial 811, or use USA North 811’s online ticket system, at least two full working days before the planned excavation date — the day you call doesn’t count toward the two days. Don’t call more than 14 calendar days ahead; the ticket won’t be issued that far out.
- Give the exact address and description of the work. Utility locators need a precise address, the boundaries of the dig area, and a description of the work — "new driveway approach, 20 ft x 12 ft, base excavation to 8 inches" is the kind of detail that gets an accurate locate.
- Wait for all affected utilities to respond. Each utility with lines in the area (gas, electric, water, sewer, cable, fiber) sends a locator to mark their lines with spray paint and flags, color-coded by utility type. Confirm every utility on the ticket has responded before digging — not just the first one to show up.
- Dig within the 28-day ticket window. The ticket is valid for 28 days from issuance. If your project is delayed past that window, you’ll need to renew or resubmit the request before excavating.
- Hand-dig or pothole near marked lines. Within roughly 24 inches of a marked utility line (the exact tolerance zone varies by utility), hand-digging or vacuum excavation rather than machine digging is the standard practice for confirming a line’s exact depth and position before running equipment near it.
Submit online or by phone: USA North 811, or dial 811 from any phone.
What counts as excavation
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Driveway or patio base prep
Excavating and compacting the base beneath a new slab counts, even at typical 4–8 inch depths.
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Footings and post holes
A fence, wall, or structure footing dug for a concrete pour is excavation, regardless of how small the hole.
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Tear-out and re-grading
Removing an old driveway and re-grading before a new pour disturbs the same ground a fresh excavation would.
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Anything below the surface
There’s no minimum-depth exemption in the law as written — when in doubt, call.
What the utility markings actually mean
Once your ticket is submitted, each utility with lines in the area sends its own locator, and each marks its lines with a standard color code so a crew can read the ground at a glance rather than guessing which flag belongs to which utility: red for electric, yellow for gas or petroleum lines, orange for communication and fiber, blue for potable water, green for sewer or drain lines, and purple for reclaimed or irrigation water — relevant on properties that use recycled water for landscaping, which is common across parts of Monterey County. Paint marks the general route along pavement or bare ground; flags mark a more precise point, often where a line changes direction or crosses the planned dig area. Not every utility responds at the same speed, and it's normal for paint to appear over a few days rather than all at once — that's exactly why the two-working-day minimum exists, and why digging the same day you call is against the law regardless of how urgent the project feels. If a mark seems to run directly through where your new driveway or footing needs to go, that's the point to call the utility directly (the ticket confirmation lists a contact per utility) rather than dig around it and hope, since lines don't always run in a perfectly straight line between two visible points.
Why this matters beyond the legal requirement
Salinas, Monterey, Seaside, and Marina all have a mix of older and newer underground utility infrastructure, and a driveway approach sits directly over where gas, water, and sewer laterals typically cross from the street to the house. Striking a gas line during a driveway pour isn't hypothetical — it's one of the most common utility-strike scenarios nationally, and it's entirely avoidable with a free phone call placed a few days ahead of the pour.
A licensed, experienced concrete contractor calls this in routinely and should say so in your contract — ask directly whether they've requested the locate and when the ticket was issued before the crew starts digging. For the separate question of whether your project also needs a city encroachment or building permit, see our permits-by-city guide. To verify your contractor's license before signing anything, use our CSLB verification walkthrough.