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BIG ISLAND · HILO

Carlsmith Beach Park

Water quality status and bacteria risk rating

📍 Hilo, Big Island — Freshwater spring lagoon · Sea turtle habitat

Checking live advisories…
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Hilo Receives 130+ Inches of Rain Per Year
Heavy rainfall is the primary water quality concern at Carlsmith Beach. Runoff from Hilo’s urban watershed can temporarily spike bacteria levels. Always wait 72 hours after significant rain before swimming here.
If It Looks Brown, Don't Swim
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Historical Bacteria Risk
⚠ Historical rating — based on long-term testing data, not current conditions.
Moderate Risk 3 / 5

Carlsmith Beach Park (Puhi Bay) is a beautiful freshwater-spring-fed lagoon in east Hilo. The beach offers calm, protected swimming popular with local families and sea turtles. However, Hilo’s massive annual rainfall (130+ inches) creates significant runoff risk after storms.

The freshwater springs that feed the lagoon also create ideal habitat for sea turtles, which regularly rest on the beach. The DOH monitors Hilo-area beaches and frequently posts advisories after heavy rain events. During extended dry periods, water quality is typically good.

Based on: High rainfall watershed, urban Hilo runoff, freshwater spring inputs, regular DOH monitoring

⚠️ The 72-Hour Rain Rule

The Department of Health recommends staying out of the ocean for at least 72 hours after heavy rain. This is especially critical in Hilo, which has the highest annual rainfall of any major U.S. city.

Carlsmith Beach Park Water Quality by Month
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⚠️ Important Disclaimer

Safe to Swim Hawaii is an independent passion project — not affiliated with the Hawaii Department of Health. Water quality 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. 🤙

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