← All beaches & hotels
OʻAHU · WAIANAE COAST

Poʻkai Bay Beach Park

Water quality status and bacteria risk rating

📍 Waianae, West Oʻahu — Protected bay · Family swimming

Checking live advisories…
Community Water Testing
The Hawai‘i Department of Health does not run routine bacteria-testing here. The readings below come from the Surfrider Foundation’s volunteer Blue Water Task Force, which fills coverage gaps DOH doesn’t reach.
Community Testing · Surfrider BWTF
PƍkaÊ»i Bay- Inside
Last sample 2026-04-16 · view full report →
10 MPN/100mL
within threshold
PƍkaÊ»i Bay- outside
Last sample 2026-01-08 · view full report →
20 MPN/100mL
within threshold
About: Volunteer water-quality monitoring by the Surfrider Foundation's Blue Water Task Force. Method: IDEXX Enterolert (MPN/100mL). Threshold: 130 MPN/100mL Beach Action Value — matches Hawaii DOH. Sampling: monthly (KauaÊ»i/Maui), biweekly (OÊ»ahu).
Source: Surfrider Foundation Blue Water Task Force · Updated 2026-05-15
If It Looks Brown, Don't Swim
Never enter murky water. After heavy rain, wait at least 72 hours. Learn more →
Historical Bacteria Risk
⚠ Historical rating — based on long-term testing data, not current conditions.
Low–Moderate Risk 2 / 5

Poʻkai Bay is a protected harbor bay on Oʻahu’s dry leeward Waianae Coast. The breakwater creates calm, wave-protected conditions popular with local families. The Waianae Coast receives under 20 inches of rain annually, meaning far less runoff than windward or north shore beaches.

The bay’s protected nature reduces ocean flushing compared to open beaches, so any runoff that enters stays longer. The DOH periodically monitors the Waianae Coast. During extended dry periods — which are common here — water quality is generally acceptable.

Based on: Leeward dry climate, breakwater protection reducing flushing, periodic DOH monitoring

⚠️ The 72-Hour Rain Rule

The Department of Health recommends at least 72 hours after heavy rain. Even dry Waianae can receive occasional heavy rain, and the bay’s limited flushing means conditions can stay elevated longer than open ocean beaches.

Get Beach Safety Alerts

Free alerts when water quality changes at your beach.

Check all Hawaii beaches & hotels →

⚠️ Important Disclaimer

Safe to Swim Hawaii is an independent passion project — not affiliated with the Hawaii Department of Health. Ratings are estimates based on publicly available data and are not real-time measurements.

Always verify with the Hawaii DOH Clean Water Branch before entering the water.

This site does not recommend or advise anyone to swim at any beach. We share government data and geographic analysis so you can make your own informed decisions. By using this site you accept full responsibility for your own safety. See our Terms of Use for full details.

When in doubt, donʻt go out. 🤙

© 2026 Safe to Swim Hawaii · safetoswimhawaii@gmail.com