Why the County Cares About Your Driveway Entrance
A driveway entrance that doesn't handle runoff correctly can flood a road ditch or wash out over time — which is why counties regulate culvert sizing and entrance grading before you cut in a new driveway.
Culvert Sizing Basics
The right culvert size depends on the drainage area feeding into that ditch, not just what fits under the driveway. Undersized culverts are the most common reason a new entrance gets flagged after the fact.
The Permit Process
Most counties require a permit and an approved culvert size before you cut in a new entrance. Getting this confirmed before excavation starts avoids a costly redo if the county rejects the work afterward.
Grading and Ditch Work
The ditch on either side of the culvert needs to be graded so water actually flows through the pipe instead of pooling or eroding around it. This is easy to get wrong if it's treated as an afterthought to the driveway itself.
Why Cut-Ins Get Rejected
The two most common rejection reasons are undersized culverts and ditch grading that doesn't match the county's drainage requirements. Both are avoidable by checking the spec against local requirements before digging, not after.