Water quality status and bacteria risk rating
📍 Hilo, Big Island — Freshwater spring lagoon · Sea turtle habitat
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, Hiloʻs 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 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.
Free alerts when water quality changes at your beach — brown water advisories, bacteria warnings, and all-clear notices.
No spam. Just safety alerts for your trip.
⚠️ 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.
When in doubt, donʻt go out. 🤙