Kaopala Basin

Kaopala Basin is an earth dam located in Maui County, Hawaii, built in 1998. It carries a High hazard potential classification and has a fair condition assessment.

About Kaopala Basin

The primary purpose of Kaopala Basin is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Maui County, Dept Of Public Works (local government). It impounds the Kaopala Gulch near Napili.

The dam stands 30 feet tall and stretches 250 feet across, creates a reservoir covering 1 acres, has a maximum storage capacity of 38 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1998, the structure is 28 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 02/29/2024.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Hawaii dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardFair ConditionEmergency Action Plan: Yes

Location

StateHawaii
CountyMaui
Nearest CityNapili
River/StreamKaopala Gulch
Coordinates20.98200, -156.67066

Physical Characteristics

Dam TypeEarth
NID Height30 ft
Dam Height30 ft
Dam Length250 ft
Year Completed1998 (28 years old)

Storage & Hydraulics

NID Storage38 acre-ft
Max Storage38 acre-ft
Surface Area1 acres
Drainage Area0 sq mi
Max Discharge7,200 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeFlood Risk Reduction
OwnerMaui County, Dept of Public Works
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection02/29/2024
Emergency Action PlanYes

Identifiers

NID IDHI00134
Federal IDHI00134
More InfoState Dam Safety Program

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