The Hawaiʻi County Department of Water Supply keeps a public notices page. Under its conservation and restriction notices, the North Kona entry reads "None." That's a real change from 2024, when much of North Kona from Mākālei to Keauhou spent months under mandatory water cuts. Look one heading down, though, and South Kona has a conservation notice posted May 27, 2026. On this page, a quiet listing only means no notice is in effect.
The August 25, 2026 Water Board minutes give a fuller picture. That month, 12 of North Kona's 14 water sources were operational or available. Honokōhau and Hōlualoa were still offline.
That gap matters to anyone pricing a North Kona home or lot on its potential for an ohana unit. Since 2024, county zoning has allowed far more accessory dwellings than it used to. Water service was never part of that change. It runs through a separate approval, unit by unit, from a system that's still recovering.
Zoning answered one question in 2024
In September 2024 the Hawaiʻi County Council passed Bill 123. The Hawaii Tribune-Herald reported that its biggest change "allows up to three ohana units — now called 'accessory dwelling units' or ADUs — to be built on a single lot," as long as the lot sits in a zoning district that permits ohana units. The bill also dropped the separate ohana building permit. Only one ADU per site may be used as a short-term vacation rental. The county record for Bill 123 shows final reading on September 17, 2024 and transmittal to the Mayor on September 25.
North Kona's own council seats weren't in favor. According to the same Tribune-Herald account, both Kona members, Rebecca Villegas and Holeka Inaba, voted against the bill along with Kohala's Cindy Evans. It passed anyway, and the entitlement now applies across eligible districts countywide, Kona included.
The bill speaks to building permits and zoning districts. It says nothing about whether a given water main can serve a third or fourth household on the same parcel.
The water rule asks a different question
The Department of Water Supply works under its own rules, and those rules don't treat a zoning entitlement as a promise of service. DWS Rule 3-1 makes a new service conditional on several things. The premises must be within DWS service limits and next to a distribution main, with adequate pressure and facilities. The new service can't impair existing customers, and the applicant must pay the applicable fees. Rule 3-1(4) reads:
"The Department shall evaluate each application for potential usage. For those water systems where the Department has determined that water is available, each dwelling unit or lot shall use a separate 5/8-inch meter at a minimum."
So every ADU is its own application, its own meter and its own availability call. The cost scales with it. The DWS rate schedule sets the facilities charge at $6,095 per additional lot, dwelling unit or equivalent unit for the period starting July 1, 2026, up from $5,500 the year before. An owner who builds out the full three ADUs pays $18,285 in facilities charges alone. Service lateral installation is billed separately on top of that.
The laterals get more expensive as the unit count climbs. Under Rule 3-5, DWS will install a second lateral on the same lot at a Board-set charge. Any lateral beyond the second has to be installed by a contractor at the applicant's expense. The rules also let DWS require system improvements and charge a prorated capital assessment where serving a property takes substantial investment.
Ongoing bills are rising too. The current brochure raised the monthly standby charge for a 5/8-inch meter from $32.82 to $35.93 on July 1, 2026, and the first-block general-use rate from $1.50 to $1.64 per 1,000 gallons. Separately, DWS staff proposed raising the Power Cost Charge from $2.53 to $3.04 per 1,000 gallons, effective October 1. The September 22, 2026 agenda records that the public hearing was held and recommends approval. Every added meter carries its own standby charge.
Why a quiet notices page understates the system
Those availability decisions come from a North Kona system that has run short on wells for most of the past two and a half years. The public record shows the sequence:
- March 30, 2024. The Hualālai Deepwell went offline unexpectedly while the Honokōhau Deepwell was already under repair, Big Island Video News reported.
- April 2024. A mandatory 25% restriction covered 18 named areas, including Kalaoa, Kona Palisades, Kailua-Kona, Kealakehe, Hōlualoa, Kahaluʻu and Keauhou. Big Island Now reported that customers were asked to refrain from irrigation and car washing.
- August 7, 2024. A new mandatory 25% restriction followed failures at the Hōlualoa and Kalaoa wells, according to KWXX.
- November 6, 2024. A temporary mandatory cut set off by a power outage in upper North Kona was lifted that evening, back to the 10% voluntary regime in place since September, Big Island Now reported.
- May 5, 2025. The 10% voluntary request was still in effect while DWS worked on electrical equipment issues and redistributed supply, per Big Island Video News.
- July 29, 2025. DWS cancelled the North Kona conservation notice and said normal use could resume.
- April 28, 2026. The Waiʻaha Deepwell's new pump had started successfully but was still waiting on Department of Health recertification. A year earlier, the March 2025 board agenda had proposed extending the repair contract to a June 30, 2025 completion date.
- August 25, 2026. Twelve of 14 sources were working. Honokōhau and Hōlualoa were still out.
Hōlualoa is one of the wells behind the August 2024 restriction, and in the August 2026 minutes it still had no return date. The DWS engineer told the board that "we need to relook at specifications for what kind of motor we are going to be putting in that well, so that return to service is still to be determined." Honokōhau was then on track for an end-of-September return, after storm conditions forced its contractor to stand down for a while. The September and October minutes will show whether it made that date once DWS posts them on its board meetings page.
The Waiʻaha repair was still unfinished about ten months after that proposed date. A permit-ready ADU plan can easily outlast the period when the system had full redundancy.
Where new supply is supposed to come from
Several projects are aimed at the shortfall, and none is a quick fix. A DWS preliminary draft environmental assessment for a North Kona Deep Well, dated April 10, 2025, describes an exploratory well as a possible municipal source. It cites growing drinking-water demand and system reliability, and it projects work starting around January 2026 and lasting up to two years. DWS has also proposed a $1.1 million emergency standby generator at Keahuolū Well, funded with up to $825,000 in federal money and a $275,000 DWS match. A generator keeps existing wells pumping through outages, and the November 2024 cut showed what a power outage alone can do.
The Department of Hawaiian Home Lands has its own draft environmental assessment for two North Kona wells to serve the Villages of Laʻi ʻŌpua and its continued development. That water is meant for that planned community. It isn't spare capacity for the rest of the district.
What this does to a listing that says "ADU potential"
When North Kona marketing mentions room for ohana units, it's describing the zoning entitlement. The water side sits in DWS hands, decided per parcel and per unit, by a system that was two sources short as of late August 2026. Two lots with the same zoning can come out differently. One fronts a main with good pressure and the other doesn't, or one needs improvements that bring a capital assessment. Compared with that difference, the $6,095 per-unit charge is the predictable part.
Questions buyers often settle before relying on ADU value:
- Is the parcel inside DWS service limits and next to a distribution main?
- How many meters and laterals already serve the lot, and would a new unit need a third lateral installed by a contractor?
- Has DWS issued anything in writing about water availability for the specific number of units planned?
- Which offline source, if any, normally supplies that part of the system, and what do the latest Water Board minutes say about it?
This is general information, not legal, permitting or financial advice. Confirm your parcel's situation directly with the Department of Water Supply, the County Planning Department and the right professionals. Our buyers guide covers the broader due diligence sequence, and our earlier look at North Kona's long-term rental tax class covers another rule that changes what a rental unit is worth.
Frequently asked questions
Is North Kona under water restrictions right now?
No. DWS lists no conservation or restriction notice for North Kona, and the last one was cancelled on July 29, 2025.
Does Bill 123 guarantee water for an ADU?
No. Bill 123 changed zoning and permitting. DWS rules separately require an availability determination and a separate meter for each dwelling unit.
What does DWS charge per added unit?
The facilities charge is $6,095 per additional dwelling unit as of July 1, 2026, plus a separate service lateral installation charge.
If a North Kona property's value depends partly on the units it could add, the team at Kona Pacific Realty can help you line up the water questions before you write an offer, or show you how that potential reads in a home valuation for a property you already own. Me ke aloha pumehana.
