Water quality status and bacteria risk rating
📍 Between Nanuakuli & Māʻili — West Oʻahu
Keaau Beach Park sits on the Waianae Coast between Nanuakuli and Māʻili, offering a wide sandy beach with some rocky sections. The beach is west-facing which provides some open-ocean flushing, but nearby cesspool infrastructure in the Waianae area elevates baseline bacteria risk.
On clear days with no recent rain, Keaau can have good water quality. The beach is less crowded than others, making it a local favorite. Rocky sections near the park offer some snorkeling, but conditions vary with weather and tide.
Based on: Waianae cesspool density, open-ocean exposure, historical DOH data
Stay out of the ocean for at least 72 hours after heavy rain on the Waianae Coast. Cesspool runoff can significantly raise bacteria levels after storms.
Free alerts when water quality changes — brown water advisories, bacteria warnings, and all-clear notices.
⚠️ Important Disclaimer
Safe to Swim Hawaii is an independent passion project — not affiliated with the Hawaii DOH. Ratings are estimates, not real-time measurements.
Always verify with the Hawaii DOH Clean Water Branch.
When in doubt, don't go out. 🤙