Scottsdale Environmentally Sensitive Lands Ordinance (ESL): Desert Preservation Limits on Your Lot

If your Scottsdale lot is north or east of the Central Arizona Project canal, the Environmentally Sensitive Lands Ordinance (ESL) likely controls how much of it you can touch. The ESL is a zoning overlay, a layer of extra rules on top of your base zoning, that protects desert and mountain land by forcing each property to keep a set share of itself in natural open space. On a custom-home lot, that share is land you cannot build on, pave, or grade, so it shapes the house before you draw a single wall. This page explains what the ESL is, who it hits, and what it means for a build.

What the ESL is and what it protects

The ESL covers 134 square miles of north and east Scottsdale desert and mountain terrain. The city is direct about why it exists:

The intent and purpose of the ESL is to identify and protect environmentally sensitive lands in the City and to promote public health and safety by managing development on these lands.

The core tool is Natural Area Open Space (NAOS), land that has to be left in its natural state forever. The ordinance requires that a percentage of each property be permanently preserved as NAOS, and the amount is not a flat number. It rises with two things: the landform (Lower Desert, Upper Desert, or Hillside) and the land slope. The required NAOS runs from about 15 percent on flat lower desert up to as much as 80 percent on steep hillside. The steeper and more sensitive the ground, the more of it you must leave alone. The ordinance also protects specific features like desert washes, vegetation, and mountain ridgelines from disturbance.

The City of Scottsdale is the authority having jurisdiction (AHJ) that adopts and enforces the ESL, so its Planning and Development staff review every north-Scottsdale lot against it.

Who it hits and how it limits a build

The ESL bites hardest on north Scottsdale custom-home lots, the large desert and foothill parcels where most build-on-your-lot projects happen. Here is what it changes:

• Your buildable area shrinks. NAOS is carved out of the lot first, so your house, driveway, pool, and graded yard all have to fit in what is left. On a hillside parcel that can mean over half the lot is off-limits.
• The desert you keep is mapped and protected. NAOS is recorded, often by easement, and you cannot later clear it for an addition or a sport court. It is permanent.
• It stacks with normal limits. ESL preservation sits on top of your setbacks (the required distance from each property line) and your lot coverage (the share of the lot the building footprint may cover). NAOS, setbacks, and coverage together define the real envelope.

For example, suppose you buy a one-acre upper-desert lot on a 10 to 15 percent slope in north Scottsdale and the ESL sets your NAOS at 45 percent. Nearly half an acre has to stay untouched desert. Your 4,000 square foot house, garage, driveway, and pool all have to fit on the remaining portion, inside your setbacks and coverage limit. A floor plan drawn as if the whole acre were buildable will not fit, and the design comes back to be reworked.

What this means for you

Check the ESL before you buy a north Scottsdale lot, not after. Two same-size lots can have very different buildable areas once NAOS is applied, so the asking price per acre can be misleading. Ask the seller or the city for the lot's landform and slope so you can estimate the NAOS percentage. You can look up the parcel on the Maricopa County Assessor parcel viewer to get started. Then design the house to the land you can actually use. Build the NAOS line into your site plan from the first sketch, because moving a footprint to clear preserved desert is one of the more expensive corrections in a Scottsdale review. If the lot is steep enough, the city's Foothills Overlay can add further hillside design rules on top of the ESL, so confirm which overlays apply.

This entry is a city-special topic in the Scottsdale module. The codes your structure is built to are in Scottsdale Adopted Building Codes , and what you file for the permit is in Scottsdale Residential Building Permit Requirements . For the lot-buying side, see how to buy land to build a house in Arizona , and for the code picture, what building codes apply in Scottsdale .

Source

The ESL purpose, the NAOS requirement, and the covered area are published by the City of Scottsdale: Environmentally Sensitive Lands Overlay on scottsdaleaz.gov . The related hillside rules are at Foothills Overlay , and the full code index is at Codes and Ordinances .

This page is general information, not a zoning determination. Overlay boundaries and NAOS percentages depend on the specific parcel, so confirm your lot's requirement with Scottsdale Planning and Development before you rely on a number.