Water quality at Duke Kahanamoku Beach
The Hilton Hawaiian Village sits at the west end of Waikiki, right where the Ala Wai Canal empties into the ocean.
That canal is essentially a drainage ditch from the 1920s that collects runoff from the entire Honolulu watershed —Â including thousands of cesspools upstream.
The good news: Duke Kahanamoku Beach (the lagoon side) is somewhat protected from the worst of the canal outflow.
The bad news: after heavy rain, bacteria from the Ala Wai spreads along the nearshore water. In 2020, water near the canal mouth
only met state safety standards 44% of the time. That number has improved to around 74%, but it's still not great.
On dry days, the water here is usually fine. After rain, give it 2-3 days.
Based on: Ala Wai Canal outflow proximity, DOH monitoring data, Surfrider BWTF compliance rates
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. Bacteria and pollutants from runoff can linger in the water longer than the brown color does.
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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, Hilton Hawaiian Village, or any government agency or hotel brand. 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. 🤙