Kauai County Water Department 2026: Phone, Address & Hours

Kauaʻi water bill pay, Koʻu Wai portal login, service transfer, emergency numbers and leak adjustment help

County of Kauai Water Department 2026: Bill Pay, Login & Customer Service

Kauaʻi water customers usually need a practical answer fast: how to log in to Koʻu Wai, why phone payments are not accepted, which payment routes add fees, where the Pua Loke Street drop box is, how to start or transfer service, what documents tenants need, who to call for low pressure or a broken meter, and whether an underground leak can qualify for an adjustment. This guide turns the official Kauaʻi Department of Water pages into a scan-first action hub with payment rules, office hours, emergency contacts, forms, rates and service steps in one place.

🔐 Portal: Koʻu Wai CAP ☎️ Billing: 808-245-5442 🚨 Business-hour emergency: 808-245-5444 🌙 After-hours emergency: 808-241-1711 📍 Office: 4398 Pua Loke St
Quick answer board

Choose the Kauaʻi Water Task You Need Right Now

💳 Pay online Use Koʻu Wai Customer Account Portal. Online debit/credit card payments carry a 2.9% + $0.30 transaction fee.
☎️ Billing question Call Billing Services at 808-245-5442 or email billing@kauaiwater.org.
🏠 Start / transfer service Use Application for Water Service if a meter box exists; use Water Clearance Form first if no meter box exists.
🚨 Emergency / service issue Business hours: 808-245-5444. Nights, weekends and holidays: Police Dispatch 808-241-1711.
Official shortcut: Start with Pay Your Water Bill for payment rules, Koʻu Wai Customer Account Portal for online account access, Sign Up or Transfer Water Service for service changes, and Contact Us for emergency numbers.
Payment safety: Kauaʻi DOW says it cannot accept payments over the phone. Do not give card, banking or account details to anyone claiming to take a DOW phone payment.
Official contacts

Kauaʻi Department of Water Contacts Users Actually Need

Need Official detail Use this for
General DOW phone 808-245-5400 General Department of Water questions and routing.
Billing Services 808-245-5442; 808-245-5400 option 2; billing@kauaiwater.org Water bill, payment, account, service setup, transfers, ABP and missing bill questions.
Business-hour emergency / operations 808-245-5444; or 808-245-5400 option 1 Water emergency, low pressure, service issue, meter damage or operations problem during business hours.
After-hours emergency Police Dispatch: 808-241-1711 Nights, weekends and holidays; dispatch contacts DOW standby crew.
Office address 4398 Pua Loke Street, Līhuʻe, HI 96766 Lobby payment, drop box, mail, forms and in-person service.
Operating hours Monday-Friday, 7:45 AM-4:30 PM Phone or appointment timing.
Lobby hours 8:00 AM-4:00 PM In-person service windows and payment visits.
Water quality 808-245-5400 option 3 Water quality, environmental and drinking water regulation questions.
Water planning / permitting 808-245-5400 option 4; wrp@kauaiwater.org Water planning, permitting and water clearance questions.
Project management 808-245-5400 option 6; pm@kauaiwater.org Design, construction plan review and inspection questions.
Best routing tip: Billing or service transfer → 808-245-5442. Water outage, low pressure or damaged meter → 808-245-5444 during business hours. After-hours water emergency → 808-241-1711.
Koʻu Wai login

Koʻu Wai Customer Account Portal Login and Registration

Koʻu Wai is the Kauaʻi Department of Water Customer Account Portal. Use it for online bill payment and account access. The registration page says to register with the primary account holder’s information as shown at the top right of the water statement.

🔐PortalKoʻu WaiCAP login
👤RegisterPrimary holderStatement top right
📝NameExact matchBill name/company
💳PayOnlineDebit / credit
⚠️BrowserNo IEUse modern browser
2026 portal update: The Koʻu Wai portal notice says Stripe security updates require customers to re-enter saved credit-card or bank-account payment information and re-establish automatic payment settings associated with credit cards beginning July 1, 2026. Automatic bill payments set up directly with DOW using a bank account are not affected.
Online bill pay

How to Pay a Kauaʻi Water Bill Online

1

Open the official payment page

Start from the official Pay Your Water Bill page.

2

Use Koʻu Wai for online payment

Click the online payment link or go directly to the Koʻu Wai Customer Account Portal.

3

Check the fee before submitting

DOW lists online debit/credit card payment with a 2.9% + $0.30 transaction fee.

4

Save proof

Save the confirmation number, date, amount, account number and receipt until the payment posts.

No phone payment: Kauaʻi DOW states it is unable to accept payments over the phone.
Payment options

Kauaʻi Water Bill Payment Options

Payment method Official detail Best use
Online Koʻu Wai Customer Account Portal; debit or credit card; 2.9% + $0.30 transaction fee. Fast payment when you accept the fee.
In person Main lobby service windows, Monday-Friday 8:00 AM-4:00 PM except holidays; cash, check or money order accepted. Cash payment or in-person billing help.
Parking lot drop box 4398 Pua Loke Street, Monday-Friday 6:00 AM-4:30 PM; check or money order only; no cash. Local drop-off during accessible hours.
Mail Department of Water, County of Kauaʻi, 4398 Pua Loke Street, Līhuʻe, HI 96766; check or money order only. Non-urgent payments.
Līhuʻe Walmart Walmart Customer Service desk; must show ID and be the account holder; $1.99 transaction fee. After-office-hours walk-in option if Walmart is open.
Meter reader DOW says meter readers do not accept bill payments. Never hand payment to a meter reader.
Drop box reminder: The Pua Loke Street drop box is not accessible outside listed hours or on holidays, and no cash is accepted.
Automatic payment

Automatic Bill Payment: Bank Draft vs Portal Card Autopay

DOW Automatic Bill Payment

To set up ABP, complete the Automatic Bill Payment Authorization form and submit it with a voided blank check to DOW in person, by email or by postal mail.

Stop ABP

To stop automatic payment, contact DOW at 808-245-5442 or billing@kauaiwater.org.

Portal-card warning: If your automatic payment was set up through the online portal with a credit card, check the 2026 Stripe security update notice in Koʻu Wai. Bank-account ABP established directly with DOW is listed as unaffected by that portal card update.
Start or transfer

Start, Stop or Transfer Kauaʻi Water Service

Service situation Official detail User action
Property already has meter service box Use the Application for Water Service. Complete application and submit required documents.
No water meter service box Submit Water Clearance Form first, residential or non-residential. Contact DOW option 4 if unsure whether a meter box exists.
Homeowner Include valid photo ID and proof of property ownership signed and dated. Attach ownership documents before sending.
Renter / tenant Include notarized rental agreement signed by owner or notarized authorization letter plus $210 refundable deposit by cash or check. Notarize documents to avoid processing delay.
Submit remotely Applications can be sent by email or postal mail; office visit is not required to turn on, stop or transfer service. Email billing@kauaiwater.org or mail to 4398 Pua Loke Street.
Timing One business day notice is required if all documents are received before 3 PM; Friday requests start following Monday, or Tuesday if Monday is a holiday. Submit earlier than move-in day.
Move out / cancel service DOW says you should cancel service so billing and account contact information can be transferred properly. Do not leave service active for the next occupant.
Move-out warning: Until service is cancelled, you can remain responsible for water usage at that property.
Forms

Kauaʻi Department of Water Forms: Which One Do You Need?

Form Use it when Where / contact
Application for Water Service Property already has an existing water meter box. billing@kauaiwater.org
Application for Temporary Water Service You need temporary fire hydrant use. billing@kauaiwater.org
Payment Plan / Promissory Note You need to arrange payments on a high or past-due water bill. billing@kauaiwater.org
Automatic Bill Payment Authorization You want your water bill automatically deducted from a bank account. billing@kauaiwater.org
Leak Adjustment Request You are requesting review for an undetected underground leak. In person only; notary required.
Agricultural Application You need new or renewal agricultural rate water service. billing@kauaiwater.org
Water Clearance Form – Residential Residential property does not yet have a water meter service connection. wrp@kauaiwater.org
Water Clearance Form – Non-residential Non-residential property needs a new water meter service connection. wrp@kauaiwater.org
Fire Hydrant Flow Test You need a fire hydrant flow test application. wrp@kauaiwater.org
Backflow Prevention Assembly Test Report A backflow test report is needed from certified testers. wrp@kauaiwater.org
Leak adjustment

Kauaʻi Leak Adjustment: Rules That Matter Before You Apply

The leak adjustment form is strict. It is not a general “high bill discount.” It applies to undetected underground leaks and requires complete documentation.

Requirement Official rule summarized What to do
Complete form The form must be filled out entirely; incomplete requests will not be considered. Check every field before submitting.
Notarized affidavit Original signed and notarized affidavit is required. Use a Notary Public; copies of notarized affidavit are not acceptable.
Repair deadline Customer must repair and stop the leak within one week after knowing or having reason to know of the leak. Call DOW quickly after a high bill or leak notice and repair fast.
Underground leak only Above-ground fixtures are not allowed, including toilet leaks, sprinkler heads and above-ground irrigation systems. Do not submit toilet/sprinkler-head leaks as underground leak adjustments.
Keep paying Customer must continue making monthly payments while the bill is investigated; late fees may apply. Ask about a payment plan if the high bill is not affordable.
Frequency limit Adjustments are granted only once every two years; services under 12 months are determined by the Manager. Make sure your request is complete the first time.
Proof Provide before/after pictures, repair bill or invoice, parts receipts and detailed repair explanation. Collect proof before submitting.
Big mistake to avoid: Do not stop paying because you submitted a leak adjustment. DOW says monthly payments remain the customer’s responsibility during the investigation process.
Service issues

Report Low Pressure, Damaged Meter, Outage or Water Service Problem

During business hours

Call Operations at 808-245-5444 or DOW at 808-245-5400 option 1.

Nights, weekends, holidays

Call Police Dispatch at 808-241-1711. Dispatch contacts the standby water crew.

Issue Likely route Have ready
Someone ran over meter Call Operations at 808-245-5444. Address, cross street, visible water flow, photos if safe.
Low pressure Call Operations; issue may be property leak, PRV failure or County line problem. Whether neighbors also have pressure loss, recent plumbing work, leak signs.
Air / cloudy water Let water sit in a glass; if it clears from bottom up, air is likely cause. Time noticed, whether all fixtures affected, if recent outage/repair nearby.
Service outage Check official service outages and emergency notices. Community/location, address, time service stopped.
Rates

Kauaʻi Water Rates and Charges: What Your Bill Includes

DOW says rates are based on water usage per 1,000 gallons, multiplied by the corresponding tier block. Customers are also charged a fixed monthly service charge and a power adjustment charge.

Charge type Official detail Why it matters
Usage charge Charged per 1,000 gallons by tier block. Higher use can move into higher tier blocks.
Monthly service charge Fixed monthly charge based on meter size. You may owe this even with low or similar usage.
Power adjustment charge Added to monthly water bill. This can change total bill beyond water use alone.
Common meter reference DOW says 5/8-inch is a good rule-of-thumb if you do not know meter size. Most residential users may start there when reading rate tables.
General-use example Effective 7/1/14 amount shown Note
5/8-inch monthly service charge $17.75 Most common meter-size rule-of-thumb.
3/4-inch monthly service charge $24.75 Check your bill under Current Activity for meter size.
1-inch monthly service charge $36.50 Larger meters carry higher monthly service charges.
0th block use charge $3.80 per 1,000 gallons Use charge tiers vary by meter size and block threshold.
1st block use charge $4.85 per 1,000 gallons Use official table for exact tier.
2nd block use charge $5.65 per 1,000 gallons Higher use may fall into higher tiers.
3rd block use charge $9.50 per 1,000 gallons High usage can raise bill quickly.
4th block use charge $10.00 per 1,000 gallons Highest listed general-use block in the table.
Bill-reading tip: If your payment amount looks similar month after month, DOW notes it bills by 1,000 gallons, so your usage may remain within the same billing range.
Temporary water

Temporary Water Service, Hydrant Use and Fire Flow Forms

Kauaʻi DOW forms include temporary water service, fire hydrant flow test and related engineering forms. Use the correct form before using hydrants, requesting fire-flow data or planning construction water.

Need Official route Contact
Temporary fire hydrant use Application for Temporary Water Service. billing@kauaiwater.org
Fire hydrant flow test Fire Hydrant Flow Test application. wrp@kauaiwater.org
Backflow prevention assembly Backflow Prevention Assembly Test Report. wrp@kauaiwater.org
Construction plan review Project Management Division. pm@kauaiwater.org; 808-245-5400 option 6
Hydrant warning: Do not use or operate a hydrant without written authorization and the correct temporary water/meter process. Unauthorized hydrant use can create pressure, billing, equipment and safety problems.
Water quality

Water Quality, Outages and Emergency Notices

Water quality questions

For water quality, environmental or drinking water regulation questions, use 808-245-5400 option 3.

Outage notices

Check official DOW service outages and emergency notices before assuming the problem is only on your property.

Cloudy water note: DOW explains that air trapped in lines can make water look cloudy. If it clears from the bottom up after sitting in a glass, air is likely the cause.
Call scripts

What to Say When Calling Kauaʻi Department of Water

Situation Say this Have ready
Portal login problem “I need help with my Koʻu Wai Customer Account Portal login or registration.” Account holder name exactly as shown on bill, account number, service address, email.
Missing bill “I did not receive my water bill when expected and need to confirm my mailing address.” Account number, service address, mailing address and phone/email.
Start / transfer service “I need to start, stop or transfer water service for this property.” Photo ID, ownership proof or notarized rental/authorization documents, move date, service address.
Tenant service “I am a tenant applying for water service and need to confirm deposit and notarized document requirements.” Notarized lease or owner authorization, $210 deposit by cash/check, photo ID.
High bill / underground leak “I have a high bill and possible underground leak. I need leak adjustment and payment plan guidance.” Bill dates, repair date, photos, repair invoice, parts receipts, affidavit plan.
Low pressure or damaged meter “I am reporting low water pressure / damaged meter at this address.” Exact address, whether neighbors are affected, photos, water flow or hazard details.
After-hours emergency “I need DOW standby crew contacted for a water emergency.” Address, cross street, type of emergency, active leak or no-water details.
Map

Kauaʻi Department of Water Map and Visit Checklist

Department of Water, County of Kauaʻi

Address: 4398 Pua Loke Street, Līhuʻe, HI 96766.
General phone: 808-245-5400.
Lobby hours: 8:00 AM-4:00 PM, Monday-Friday except holidays.

Visit checklist: Bring your water bill, account number, photo ID, payment method, notarized tenant documents if needed, ownership proof if applicable, repair documentation for leak adjustment, and any DOW letter or outage notice.
FAQs

County of Kauai Water Department Bill Pay, Login and Customer Service FAQs

How do I pay my Kauaʻi water bill online?

Use the official Koʻu Wai Customer Account Portal linked from Kauaʻi Department of Water’s Pay Your Water Bill page. Online debit or credit card payments carry a 2.9% plus $0.30 transaction fee.

Does Kauaʻi DOW accept payment by phone?

No. The Pay Your Water Bill page says the Department of Water is unable to accept payments over the phone.

What is the Kauaʻi DOW billing phone number?

Billing Services is listed at 808-245-5442 or 808-245-5400 option 2. The billing email is billing@kauaiwater.org.

Where is the Kauaʻi Department of Water office?

The Department of Water office is at 4398 Pua Loke Street, Līhuʻe, HI 96766.

What are the lobby hours?

The Contact Us page lists hours of operation Monday-Friday, 7:45 AM to 4:30 PM, and lobby hours 8:00 AM to 4:00 PM.

What number do I call for a water emergency?

During business hours, call 808-245-5444 or 808-245-5400 option 1. For nights, weekends and holidays, call Police Dispatch at 808-241-1711.

Can I pay at the Līhuʻe Walmart?

Yes. DOW says walk-in payments are accepted at the Līhuʻe Walmart Customer Service desk during Walmart business hours. You must show ID and be the account holder. A $1.99 transaction fee applies.

Can someone else pay my account?

DOW says yes if they have your account number, a copy of your bill or physical address to identify the correct billing account. The exception is Walmart, where you must be the account holder.

How do I start water service in Kauaʻi?

If the property already has a water meter service box, use the Application for Water Service. If there is no meter service box, submit the residential or non-residential Water Clearance Form first.

What documents do tenants need for water service?

Tenants need a valid photo ID and either a notarized rental agreement signed by the property owner or a notarized authorization letter, plus a $210 refundable deposit by cash or check.

How much notice is needed to start service?

DOW says one business day notice is required if complete documents are received before 3 PM. Friday requests are not accommodated until the following Monday, or Tuesday if Monday is a holiday.

How do I get a leak adjustment?

Use the Leak Adjustment Request form for undetected underground leaks only. It must be complete, include an original notarized affidavit, and include repair documentation such as pictures, invoices and parts receipts. Customers must keep paying monthly bills during review.

Are toilet leaks or above-ground sprinkler leaks eligible?

No. The leak adjustment instructions exclude above-ground fixtures, including toilet leaks, toilet flaps, sprinkler heads, above-ground irrigation systems and exposed waterlines within the premises.

How often can an adjustment be granted?

The leak adjustment instructions say approved adjustments are granted only once every two years. Adjustments on services less than 12 months are determined by the Manager.

Final takeaway

Best Way to Use the County of Kauai Water Department Page

Use this route: Online payment → Koʻu Wai CAP. Billing questions → 808-245-5442. Business-hour water emergency → 808-245-5444. Nights/weekends/holidays → 808-241-1711. Start/transfer service → Application for Water Service or Water Clearance Form. Leak adjustment → underground leak form with notarized affidavit and repair proof. Payment methods → online, lobby, drop box, mail, Walmart or automatic bill payment.

This page is built for Kauaʻi customers who want direct answers, not filler. Every section above gives the official phone number, portal, payment method, form, fee, document requirement, emergency route, rate clue or next step needed to solve a water bill or service problem.

Editorial note: This independent guide summarizes official Kauaʻi Department of Water and County of Kauaʻi resources for easier public use. Payment fees, portal notices, lobby hours, drop box access, forms, deposits, service timing, rates, emergency procedures and leak adjustment rules can change. Confirm final details on official kauaiwater.org, kauaiwater.kouwai.org or kauai.gov pages before paying, submitting documents, requesting service, relying on rates or applying for an adjustment.

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