Paradise Valley Grading and Drainage Permit: When Earthwork Needs a Permit and What the Plan Must Show

You need a grading permit in Paradise Valley any time you move enough dirt to change the lot's slope or the way water drains across it. This is a separate permit from the house permit and the hillside review, though on a sloped lot all three run together. The grading permit is where the Town checks that your cut, fill, and drainage keep water on your lot and off your neighbors. One threshold catches nearly every custom build here. Add 999 square feet of hard surface, or price the work above $500,000, and a grading and drainage plan attaches to the house permit whether or not you thought you were grading.

When grading needs a permit

The permit is tied to changing the land, not just to big excavation. The Town's own materials describe the trigger directly:

[A grading permit is] required when dirt or earth work is being completed (excavating or filling) and there are changes made to the current gradient of the land and drainage conditions.

So cutting a building pad, filling a low spot, or reshaping how water runs all call for the permit. A grading plan also gets pulled into the house permit at a size threshold. The Town requires a grading and drainage plan with a building permit:

where 999 sf or more of impervious area is added or if the value of the work is greater than $500,000.

A new custom home in Paradise Valley clears both marks easily. The house, driveway, and patios add well over 999 square feet of hard surface, and estate-scale valuations pass half a million dollars. So plan on the grading and drainage plan as part of the build, not an extra.

What the grading and drainage plan must show

Grading in Paradise Valley is an engineer's document, not a sketch. An Arizona registered civil engineer has to prepare the core sheets: a legal survey, the grading and drainage plan, and a Storm Water Pollution Prevention Plan (SWPPP). Two outside approvals attach at set thresholds:

• If your project disturbs one acre or more, you also file a Notice of Intent with the state. That earns coverage under Arizona's AZPDES Construction General Permit, the stormwater permit ADEQ runs, and the SWPPP is the plan behind that coverage.
• If the work disturbs a tenth of an acre or more (4,356 square feet), you file a dust control plan, or a Maricopa County air quality permit for larger disturbance.

The drainage half of the plan is the part the Town checks hardest. Your engineer has to show where stormwater goes. A graded lot cannot push runoff onto the lot next door, or into a wash in a way that erodes it. On the Town's large lots, that often means shaping the pad and driveway to hold and route water on your own ground.

How hillside rules cap your grading

On a sloped lot, the grading permit is not the only limit. Paradise Valley's Hillside Development Regulations (Article XXII) cap how much of a lot you may disturb once the slope hits 10 percent. The steeper the ground, the smaller that share gets. The Town's Hillside Building Committee reviews grading, drainage, and retaining walls before any earth moves. So your grading plan has to fit inside the disturbance cap, not merely balance cut against fill.

For example, take a 1.2-acre lot on a 15 percent slope. Three thresholds stack up. Total disturbance tops one acre, so you file the ADEQ Notice of Intent and a SWPPP on top of the Town permit. It also tops a tenth of an acre, so a dust control plan comes with it. And the slope is over 10 percent, so Article XXII caps how much of the site you may touch at all. Your civil engineer then has to fit the pad, the driveway, and the drainage inside that cap while still routing water safely downhill. All three have to agree before the Town issues the permit.

What this means for you

Budget the grading and drainage plan as a real line item on almost every Paradise Valley build, drawn by an Arizona registered civil engineer. Pin down your total disturbance early. Crossing one acre adds the ADEQ stormwater permit, and crossing a tenth of an acre adds dust control. Get the drainage right the first time, because pushing water onto a neighbor is a common and expensive correction. On a sloped lot, hand your engineer the hillside disturbance cap up front, so the plan is drawn to fit it rather than reworked around it. The Town of Paradise Valley is the authority having jurisdiction (AHJ) here, and its Building and Engineering staff can confirm your lot's thresholds before you finalize anything.

Grading is the permit the rest of a Paradise Valley build waits on. The disturbance caps that limit it on a slope are in Paradise Valley Hillside Development Requirements. The house permit that the grading plan attaches to is in Paradise Valley Residential Building Permit Requirements, and the field checks are in Paradise Valley Building Inspections. For the lot-buying side, see how to buy land to build a house in Arizona, and for the full sequence, the steps to building a custom home in Arizona.

Source

The Town of Paradise Valley publishes the grading permit trigger, the building-permit grading threshold, and the required civil-engineered submittals on Permits and Handouts at paradisevalleyaz.gov. The one-acre stormwater rule is set by ADEQ's AZPDES Construction General Permit. The dust control permit is run by Maricopa County Air Quality.

Three agencies set the numbers on this page, and they revise them on separate schedules. Check the 999-square-foot and one-acre thresholds against each agency's current page before your engineer starts drawing.