Maui’s New Water Conservation Rules: What Coastal Builders Need to Know About SMA Permits

Updated March 1, 2026 — Maui County has rolled out strict new water conservation rules following the County Council’s approval of Bill 158. The rules, which take effect March 1, aim to curb water waste and preserve the island’s shrinking supply. While the measures apply island‑wide, they have important implications for anyone planning construction or renovation in a Special Management Area (SMA). Coastal homeowners and builders should understand these changes now so they can incorporate water‑saving features into their plans and avoid delays during SMA permitting.

What Changed?

At a February open house hosted by the Department of Water Supply (DWS), county officials explained how the updated rules work. Under the amended code, potable water may not be used to irrigate lawns and landscaped areas between 9 a.m. and 5 p.m. and only on designated days. The schedule varies by address: even‑numbered residences can water on Monday, Wednesday and Friday; odd‑numbered residences on Tuesday, Thursday and Saturday; and non‑residential and multi‑family properties follow their own three‑day schedules. Exceptions exist for irrigation using recycled water, greywater, rainwater catchment and newly installed landscapes during the first four weeks. Watering for public health or safety, maintenance or fire control is also exempt.

Beyond scheduling, the code defines water waste and makes it illegal to let potable water run onto adjacent property, streets or sidewalks or to ignore leaks. DWS Director John Stufflebean said the rules are a response to increasingly frequent droughts and will “help us make every drop count” while still keeping yards and businesses vibrant.

The ordinance also introduces sector‑specific requirements:

New development and landscaping: All new or upgraded landscape projects for commercial, hotel, multi‑family and public‑use developments—as well as larger single‑family and agricultural lots—must use high‑efficiency irrigation systems and water‑efficient landscaping such as xeriscaping with native or drought‑tolerant plants. Developers must provide maintenance guidance to buyers, who in turn must operate systems efficiently.
Commercial car washes and laundries: New facilities must install water reclamation systems that treat and reuse water. Self‑service car washes must use high‑efficiency pressure nozzles, while existing facilities only need to upgrade if they seek additional water service.
Lodging and food service: Hotels, motels and resorts must adopt practices such as towel‑and‑linen reuse programs, water‑efficient fixtures, smart irrigation systems with rain and wind sensors and the use of trained landscapers. Restaurants are encouraged to serve complimentary drinking water only upon request.
Private swimming pools: Pools unused for more than 30 consecutive days must be covered to reduce evaporation; existing pools have until March 1 2027 to comply.

Why Water Rules Matter for SMA Permits

Special Management Area permits are already complex. Applicants must prepare site plans, wastewater system designs, maps and narratives demonstrating compliance with Hawai‘i Revised Statutes Chapter 205A, and major projects often require a 150‑page Environmental Assessment. These new water rules add another layer of scrutiny—especially near the shoreline, where resource conservation is critical.

Here’s why water conservation could influence your SMA application:

Demonstrating sustainability: SMA reviewers evaluate environmental impacts holistically. Showing that your project uses high‑efficiency irrigation, drought‑tolerant landscaping and greywater systems can help demonstrate that it won’t strain county water supplies.
Condition of approval: County planning commissions may require adherence to the new watering schedule or installation of smart irrigation as conditions for SMA approval. Failing to incorporate these features could result in revisions or delays.
Compatibility with surrounding uses: Water waste can damage adjacent properties and coastal ecosystems. Designing landscapes and drainage to prevent runoff and leaks—now outlawed by the ordinance—will reduce the risk of complaints during public hearings.
Cost and timeline impacts: Upgrading irrigation or installing water reclamation systems may increase upfront costs, but doing so early avoids expensive retrofits later. Moreover, projects that align with conservation goals are less likely to face community opposition that can extend review timelines.

If you’re uncertain how these rules apply to your property, feel free to email ryan@schawaii.com or call 808‑762‑2345. Shoreline Consulting Hawai‘i is happy to talk you through the specifics.

Tips for Coastal Homeowners and Builders

To prepare for a more water‑conscious permitting environment, consider these steps:

Audit your site’s water use. Identify existing irrigation systems, plumbing fixtures and landscaping that rely heavily on potable water. Look for opportunities to switch to greywater, rainwater catchment or drought‑tolerant plantings.
Incorporate high‑efficiency irrigation. Drip systems, weather‑based controllers and soil moisture sensors reduce water use and comply with the ordinance’s requirements for new developments.
Choose native and xeriscape plants. Native species are adapted to Hawai‘i’s climate and typically require less water. Xeriscaping adds aesthetic appeal while cutting irrigation demands.
Plan for water reuse. If your project includes a car wash, laundry facility or pool, design water reclamation or cover systems upfront. Reused water also helps meet SMA sustainability goals.
Schedule irrigation wisely. Even if you have an efficient system, watering outside the permitted hours and days can lead to violations. Set timers to water early in the morning or late in the evening and adjust schedules for even or odd addresses.
Engage neighbors. Discuss water‑saving measures with adjacent property owners. Collaboration on shared landscaping or greywater systems can reduce costs and show community support during SMA hearings.

How Shoreline Consulting Hawai‘i Can Help

Navigating Hawai‘i’s evolving regulatory landscape is what we do best. Shoreline Consulting Hawai‘i specializes in helping homeowners, businesses and developers obtain SMA permits and manage coastal projects. Our services include:

Document preparation: We assemble site plans, wastewater designs, water conservation plans and long‑form narratives showing compliance with Chapter 205A and the new water conservation ordinance.
Agency coordination: We work closely with county planning departments, the Department of Water Supply and other state and federal agencies to ensure that your project meets both SMA and water‑use requirements. We also engage cultural practitioners to address archaeological and cultural concerns.
Professional partnerships: While we don’t employ engineers or architects on staff, we collaborate with trusted professionals who can provide high‑efficiency irrigation designs, greywater systems and structural plans tailored to coastal conditions.
Policy monitoring: Our team tracks legislation and county initiatives—including water codes, planning appointments and SMA rule changes—so we can alert clients to new requirements and opportunities.

From concept to completion, we offer project management and architectural design services that align with Hawai‘i’s cultural values and environmental standards. To learn more, send us an email at ryan@schawaii.com or call 808‑762‑2345.

Looking Ahead

Maui’s updated water conservation rules reflect a broader shift toward sustainability and resilience. As climate change intensifies droughts and sea‑level rise, coastal development must balance private ambition with public resource protection. These rules signal that counties are willing to enforce conservation—not just recommend it—and that SMA permit reviews will increasingly factor in water use. By planning ahead, incorporating efficient systems and working with experienced consultants, you can protect your investment while supporting Hawai‘i’s long‑term water security and shoreline health. For personalized guidance on your project, contact Shoreline Consulting Hawai‘i at ryan@schawaii.com or 808‑762‑2345 today.