Drainage, Stormwater & Flood

Grading and Drainage Plan

Stamped grading and drainage plan for building permits, showing finished grades, slopes, swales and where water goes. Typical US fees run $800 to $5,000, and most projects take 1 to 4 weeks. Our drawings, calculations and reports are sealed by a Professional Engineer (PE) licensed in the state where your project is located, ready for permit submission.

Typical US fee$800 to $5,000

Typical timeline1 to 4 weeks

Permit drawingsSealed by a PE

What the work involves

A grading and drainage plan shows existing and proposed elevations, slopes away from buildings, swales, inlets, pipes and outfalls. Many jurisdictions require one for new homes, additions, pools and commercial projects, sometimes with calculations showing runoff does not increase. It is prepared by a civil engineer from a topographic survey.

When you need it

Building permit requires a grading and drainage plan
New home, addition or pool changing site grades
Adding driveway, patio or other impervious area
Lot drains toward a neighbor or the house

What you receive

Stamped grading and drainage plan
Drainage calculations if required
Erosion control notes
Spot elevations and details

What drives the cost

Estimate for residential plans; commercial grading plans are typically part of a larger site plan fee. Survey costs are separate.

Related calculators

Cut and Fill Volume Calculator (Average End Area)Compute earthwork volume between two cross-sections using the average end area method, in cubic feet and cubic yards.Slope and Grade Percent CalculatorConvert rise and run into percent grade, angle in degrees and slope ratio (run:rise) for ramps, driveways and site grading.

Frequently asked questions

How much does grading and Drainage Plan cost?

Across the US, grading and Drainage Plan usually costs $800 to $5,000. Estimate for residential plans; commercial grading plans are typically part of a larger site plan fee. Survey costs are separate.

How long does grading and Drainage Plan take?

Plan on 1 to 4 weeks from signed proposal to stamped deliverables, longer if a site visit, soil testing or a permit review cycle is involved.

Do I need a licensed PE for grading and Drainage Plan?

In most US jurisdictions, yes. When the work needs a permit, the plans, calculations or report usually must be sealed by a Professional Engineer licensed in the state where the project is located. Every deliverable we issue for permit is sealed that way.

Will I also need a land surveyor?

Sometimes. Depending on the site, grading and Drainage Plan can also involve a land surveyor or landscape architect. We tell you up front which other professionals your project needs and coordinate with them so the drawings agree.

Who do you provide grading and Drainage Plan for?

Most of our clients for this service are homeowners, contractors, developers and architects. Describe your project and one of our engineers will reply with scope, fee and schedule.

Is a grading plan the same as a site plan?

They overlap. A site plan shows what is built where; a grading plan focuses on elevations and drainage. Many residential sets combine them.

Do I need a survey first?

Usually yes, since the engineer needs existing elevations. Some jurisdictions accept a topographic survey prepared within a set number of years.

Will the city check the grading after construction?

Many jurisdictions require a final grade inspection or an as-built grading certification by an engineer or surveyor. Keeping the approved plan handy helps your contractor hit the required grades.

What slope keeps water away from my house?

Residential code generally requires 6 in. of fall in the first 10 ft, or swales and drains where lot lines prevent it.