Water quality status and bacteria risk rating
Also known as: Black Rock Beach, Puʻu Kekaʻa
📍 On Maui's west coast, about 30 minutes north of Kahului Airport
Ka'anapali Beach is a DOH-monitored beach on West Maui's resort coast. While the beach itself generally passes routine testing, the surrounding area faces significant water quality challenges. The Lahaina Wastewater Reclamation Facility uses injection wells that discharge treated effluent underground, and USGS studies have confirmed this wastewater reaches coastal waters along the Ka'anapali shoreline.
Nearby Hanakaoo Beach Park (less than a mile south) tested at 1,298 per 100mL enterococci in February 2026 — over 10 times the safe swimming threshold of 130. All 19 West Maui beaches sampled by community monitoring group Hui O Ka Wai Ola have been classified as "impaired" for sediment and nutrient levels.
Based on: DOH beach monitoring, USGS injection well studies, Hui O Ka Wai Ola water quality data, Hanakaoo Beach Park bacteria results
The Hawaii Department of Health recommends staying out of the ocean for at least 72 hours after heavy rain, even if the water looks clear. At Ka'anapali, this is especially important because West Maui's steep watersheds funnel runoff directly to the coast. The nearby streams and drainage infrastructure can carry sediment and bacteria to the beach quickly after storms.
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⚠️ Important Disclaimer
Safe to Swim Hawaii is an independent passion project — it is not affiliated with the Hawaii Department of Health or any government agency. Water quality ratings on this site are estimates based on publicly available testing data and geographic analysis. They are not real-time measurements and may not reflect current conditions. “No DOH Alerts” means no advisory is currently posted — it does not mean the water was tested and found safe. DOH only monitors a fraction of Hawaii’s beaches, and some areas have no regular testing at all.
Always verify current water quality conditions with the Hawaii Department of Health Clean Water Branch before entering the water. This site is for informational purposes only and should not be the sole basis for any swimming decisions.
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When in doubt, don't go out. 🤙