Low-Water-Use Landscape Ordinances in Phoenix, Scottsdale, Tucson, and Mesa: A Developer’s Comparison

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Low-Water-Use Landscape Ordinances in Phoenix, Scottsdale, Tucson, and Mesa: A Developer's Comparison

A developer moving a retail pad site from Chandler into Tucson called us three weeks before submittal last year. He was pretty confident the planting plan that had cleared Mesa’s review six months earlier would sail through just as easily. It didn’t. Tucson’s reviewers weren’t grading the plant list at all; they wanted a rainwater harvesting plan showing how the site would meet half its landscape water demand from captured runoff. That’s a requirement that doesn’t exist anywhere else in the Valley, and the gap between what a client assumes is one “Arizona xeriscape ordinance” and what four cities actually enforce is the reason we’re writing this.

Here’s the short version. Phoenix, Scottsdale, Tucson, and Mesa each regulate low-water-use landscaping through separate code sections, and the compliance mechanisms aren’t interchangeable. Phoenix folds xeriscape and native-plant standards into its zoning and design review code. In Scottsdale, low-water landscaping gets absorbed into something much bigger: an Environmentally Sensitive Lands framework covering roughly two-thirds of the city. Tucson stands apart from both. It’s the only jurisdiction here with a mandatory water-harvesting percentage built into landscape design. Mesa, meanwhile, keeps its xeriscape rules inside Title 11 zoning and leans on a rebate program instead of a mandate. Thresholds, definitions, review triggers — none of it lines up across the four, and that’s exactly the detail that trips up a plan set designed once and dropped into four jurisdictions.

Evergreen Design Group has practiced land planning, landscape architecture, and irrigation design across the Phoenix and Tucson metros since 2005, under Arizona Firm Registration 22536-0. What follows is a working comparison of how each city handles low-water-use compliance, built for teams scoping a multi-site Valley portfolio.

Phoenix Low-Water-Use Landscaping Requirements

Phoenix regulates landscaping primarily through Section 703 of the Zoning Ordinance, with design review guidelines under Section 507 Tab A layered on top for projects that trigger that review. The baseline expectation for commercial and multifamily sites is desert-adapted plant selection, shade coverage in parking areas, and screening standards that apply regardless of district. Where a project falls under the Native Plant Preservation Ordinance — protected saguaros or other regulated native species on site — that adds a separate salvage-and-relocation review that has to be resolved before grading starts, not after.

Phoenix does not mandate a harvesting percentage tied to landscape design. That's worth being precise about, since it's easy to conflate with Tucson's rule given how often the two cities get mentioned in the same breath. Instead, Phoenix runs a Green Stormwater Infrastructure (GSI) program under City Code Chapter 32C, covering bioswales, permeable pavement, curb openings, and stormwater harvest-and-reuse elements. The city actively encourages developers to incorporate it. The Planning & Development Department publishes GSI guidelines and a residential handbook, and some right-of-way and site-specific projects will need Planning & Development or Street Transportation sign-off to use it. But GSI is a stormwater-quality and flow-reduction tool, not a landscape water budget. A Phoenix commercial project can be fully xeriscape-compliant without harvesting a drop of rainwater for irrigation, which is not true forty minutes south.

For teams accustomed to Tucson's harvesting math, that's often a relief. Phoenix's landscape compliance path leans more on plant selection, shade ratios, and design review than on hydrology calculations. Still, it's worth budgeting design time for GSI where a site's drainage plan makes it a natural fit, since retrofitting it after civil design is locked tends to cost more than building it in from the start.

Scottsdale Xeriscape Ordinance and the Environmentally Sensitive Lands Overlay

Scottsdale's low-water-use landscaping requirements sit inside its zoning ordinance, but for a large share of commercial and multifamily sites, the landscape conversation gets absorbed into something bigger: the Environmentally Sensitive Lands Ordinance (ESLO). Adopted in 1991 and amended several times since, ESLO governs roughly 134 square miles of desert and mountain terrain north and east of the Central Arizona Project Canal, which in practice covers a large portion of the city's remaining developable land.

ESLO requires a percentage of each qualifying property to be permanently preserved as Natural Area Open Space (NAOS), with the exact percentage driven by slope and other site conditions rather than a flat citywide number. Once NAOS boundaries are set, that land has to stay in its natural desert state — no grading, filling, or clearing inside the easement, ever. Outside the NAOS boundary, any landscaping has to draw from Scottsdale's indigenous and desert-appropriate plant list, and certain species (citrus and palm among them) are prohibited outright in ESL-designated areas because they clash with the native aesthetic and demand more water than the ordinance is built around.

The practical upshot for a developer: on a Scottsdale parcel touching the ESL overlay, the low-water-use landscape plan can't be finalized until NAOS boundaries are established, and that has to happen early — before civil grading, not alongside it. Sites outside the ESL boundary follow a more conventional xeriscape review, closer in spirit to Phoenix's, but it's worth confirming a parcel's ESL status before assuming that's the track you're on.

Tucson Low-Water-Use Landscaping and the Commercial Rainwater Harvesting Ordinance

Tucson is where this comparison gets its sharpest edge. In 2008, Tucson adopted Ordinance No. 10597, the nation's first ordinance requiring commercial developments to harvest rainwater for a fixed share of their landscape irrigation. Every commercial project with required landscaping has to submit a Rainwater Harvesting Plan made up of two pieces: a Site Water Budget and a Water Harvesting Implementation Plan, and together they have to demonstrate that harvested rainwater will meet at least 50% of the site's annual landscape water demand. On some projects, that requirement steps up toward 75% within three years of occupancy.

This is not a paperwork exercise. Meeting the 50% threshold depends on how the site is graded — catchment areas, basin sizing, and flow direction all have to be worked out between the civil engineer and the landscape architect from the earliest site plan, because retrofitting harvesting capacity onto a grading plan that wasn't designed for it rarely pencils out. The city backs this up with inspection: sites get checked post-grading and again before certificate of occupancy, and enforcement has tightened noticeably in recent years. A city investigation of commercial projects built between 2016 and 2020 found that a large majority were exceeding the water budget the harvesting ordinance was supposed to prevent, which pushed Tucson's council toward stricter compliance review starting in 2022.

Practically, this means a Tucson commercial site needs the water budget and harvesting design settled before the landscape palette is finalized, not after. It also means a plant list and irrigation approach that worked fine in Phoenix, Scottsdale, or Mesa cannot simply be copied over — the underlying hydrology has to be recalculated for Tucson's harvesting math from the ground up.

Mesa Xeriscape Requirements for Commercial and Multifamily Sites

Mesa's landscape standards live in Title 11 (the Zoning Ordinance), Article 4, Chapter 33. Commercial and multifamily sites are required to landscape non-building, non-paved areas using a xeriscape approach, with plant selection driven by Mesa's arid-zone climate designation and reviewed against the city's xeriscape principles for plant selection, irrigation, soil preparation, and ongoing maintenance.

Mesa doesn't pair its xeriscape standard with a harvesting mandate the way Tucson does. Instead, the city leans on incentives: the Grass-to-Xeriscape program pays a per-square-foot rebate to convert existing turf to low-water desert landscaping, which is a useful tool on retrofit and redevelopment projects but isn't a substitute for meeting the baseline xeriscape standard on new construction. Mesa also enforces permanent water-conservation rules that prohibit irrigation runoff and watering within 48 hours of measurable rainfall — a detail worth building into irrigation controller programming so a site doesn't get cited for something as avoidable as a scheduling conflict.

Of the four cities, Mesa's compliance path is generally the most straightforward for a landscape architect to navigate, largely because it doesn't carry an overlay layer like Scottsdale's ESLO or a hydrology-driven mandate like Tucson's. That doesn't mean it's less important to get right — an Arizona-licensed landscape architect still has to design to the city's xeriscape criteria and get it approved before a certificate of occupancy is issued.

Comparing Low-Water-Use Landscape Ordinances Across Jurisdictions

The table below lines up the four frameworks side by side. The row that tends to catch developers off guard is the rainwater harvesting mandate — it’s easy to assume that because Phoenix and Tucson are both desert cities with aggressive conservation messaging, they regulate the same way. They don’t.

Note: Ordinance thresholds and code sections are current as of this writing but subject to amendment. We verify current code against the applicable jurisdiction as a standard part of scoping every engagement, and recommend the same before finalizing any water budget calculation.

What This Means for Multi-Jurisdiction Development Portfolios

If your program has sites in more than one of these four cities at once, sequence your landscape and civil coordination around where the compliance mechanism is hydrology-driven, not just where entitlements are moving fastest. Tucson sites need the water budget and harvesting design resolved early because the grading plan has to be built around it. Scottsdale sites touching the ESL overlay need NAOS boundaries established before civil design gets very far along. Phoenix and Mesa carry more flexibility in sequencing, though a Phoenix site incorporating GSI benefits from the same early coordination, since retrofitting drainage-integrated landscape elements after civil is locked is rarely cheap.

The bigger risk on a multi-city portfolio has less to do with any single jurisdiction’s complexity and more to do with cross-contamination between them. A landscape architect who designs the Mesa prototype first, then adapts it for Tucson without rebuilding the water budget from scratch, is the most common way we see harvesting compliance fall short after the fact. Running land planning, landscape architecture, and irrigation design through one team across all four jurisdictions, rather than four separate local consultants, is the most reliable way to keep a plant palette or compliance approach built for one city from getting mistakenly carried into another.

Our team coordinates land planning, landscape architecture, and irrigation design in-house, which means the same firm carries a project’s water budget calculations from Phoenix schematic design through Tucson construction documents. Nobody has to hand off the file, re-explain the site to a new consultant, or catch a plant palette that quietly drifted from one city’s rules into another’s.

For asset managers and CFOs evaluating the timing of an AB 1572 retrofit program, the financial calculus favors early action over deadline-driven compression — for several reasons.

Frequently Asked Questions About Low-Water-Use Landscape Ordinances

No. Phoenix does not mandate a percentage of landscape water demand from harvested rainwater. The city’s Green Stormwater Infrastructure (GSI) program encourages harvesting and reuse elements as part of stormwater management, but GSI is a stormwater-quality and flow-reduction tool under City Code Chapter 32C, not a landscape irrigation requirement. Tucson is the jurisdiction with a mandatory harvesting percentage.

Tucson, by a wide margin. Its Commercial Rainwater Harvesting Ordinance (No. 10597) requires new commercial development to meet at least 50% of annual landscape water demand from harvested rainwater, with some projects required to reach 75% within three years of occupancy. No other jurisdiction covered here — Phoenix, Scottsdale, or Mesa — imposes a comparable mandate.

On parcels within the ESL overlay — roughly two-thirds of the city’s land area, concentrated north and east of the Central Arizona Project Canal — a Natural Area Open Space (NAOS) percentage has to be established before the rest of the site plan can be finalized. That NAOS land must remain in a natural, undisturbed state permanently, and landscaping outside the NAOS boundary has to draw from Scottsdale’s approved indigenous plant list. Sites outside the ESL boundary follow a more conventional xeriscape review process.

Yes, through the Grass-to-Xeriscape rebate program. It pays out per square foot of live turf converted, which is genuinely useful on retrofit projects but doesn’t replace the baseline xeriscape standard new construction has to meet under Title 11, Chapter 33 regardless.

Start with whichever jurisdictions have hydrology tied directly to compliance, not whichever site is closest to breaking ground. In practice that means Tucson first — the water budget and harvesting design need to be resolved at the earliest site plan stage, since grading has to be built around it, and there’s no fixing that later without expensive rework. Scottsdale sites touching the ESL overlay come next, since NAOS boundaries need to be set before civil design gets very far along. Phoenix and Mesa give you more room to sequence flexibly, though a Phoenix site with GSI in the drainage plan still benefits from getting landscape and civil talking early.

One firm can absolutely handle it, and there’s a real advantage to doing it that way. The failure mode we see most often on multi-city portfolios isn’t any single city’s code — it’s a plant palette or water budget approach designed for one jurisdiction getting carried, unchanged, into another where it doesn’t hold up. A single team managing land planning, landscape architecture, and irrigation design across the portfolio keeps that from happening, and keeps the water budget math specific to each site’s actual jurisdiction.

Scope Your Multi-City Landscape Compliance With Evergreen Design Group

Evergreen Design Group has coordinated land planning, landscape architecture, and irrigation design across the Phoenix and Tucson metros since 2005, under Arizona Firm Registration 22536-0. Whether your portfolio includes Phoenix, Scottsdale, Tucson, Mesa, or all four, contact our team to scope water budget compliance, xeriscape planting plans, and jurisdictional review before your next submittal.

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Author: Rodney McNabb

Evergreen Design Group, a landscape architectural firm, was formed in 2005 by Rodney McNabb. After serving seven years in the U.S. Marine Corps, Rodney entered the landscape contracting business in 1992. Beginning his career as a landscape chemical applicator, Rodney’s employer quickly realized that Rodney was in the wrong position when he kept unintentionally killing all the grass he was spraying for weeds. While this was a commercial landscape maintenance business, Rodney was quickly re-routed to fill the company’s first sales and estimator position for landscape construction projects. This is where Rodney began to excel. After a few short years, he was promoted to oversee the operations of the different branch offices of this company. He even went to work for another firm where he was a regional manager overseeing multiple offices in multiple states that focused on the exterior and interior landscape maintenance of shopping malls. Rodney eventually formed his full-service landscape company – focusing on design, installation, and maintenance. While enjoying the contractor world, he enjoyed the design side more and created Evergreen Design Group to focus strictly on landscape design and consulting. Evergreen Design Group grew quickly and efficiently. The firm now employs approximately 15 landscape architects, landscape designers, and irrigation designers – and focuses on projects all over the U.S.