Question 1

Is it safe to swim at Kahana Bay Beach?

Accepted Answer

Kahana Bay Beach has a Moderate bacteria risk rating (3 out of 5). Kahana Stream empties directly into the bay, bringing significant freshwater runoff after rain. The bay is beautiful and scenic, but bacteria levels near the stream mouth can be elevated, especially after storms. Always check DOH advisories before swimming.

Question 2

What affects water quality at Kahana Bay?

Accepted Answer

The primary factor is Kahana Stream, which flows from the Kahana Valley directly into the bay. The windward side of Oahu receives substantial rainfall, and after storms the stream carries sediment, bacteria, and organic matter into the swimming area. The enclosed bay shape can also slow water circulation compared to open coast beaches.

Question 3

Is there stream runoff at Kahana Bay?

Accepted Answer

Yes, Kahana Stream is the main concern. It flows from Kahana Valley (one of the wettest valleys on the windward coast) directly into the bay. After any significant rain, the stream discharge increases dramatically and can turn the nearshore water brown. Avoid swimming near the stream mouth, especially after rain.

Question 4

Can you camp at Kahana Bay?

Accepted Answer

Yes, Kahana Bay Beach Park has a popular campground with permits available through the City and County of Honolulu. The camping area is scenic with mountain and ocean views. If you plan to swim during your camping trip, check water conditions first and avoid the water for 72 hours after heavy rain.

Question 5

When is the best time to swim at Kahana Bay?

Accepted Answer

The best time to swim at Kahana Bay is during extended dry weather when there has been no significant rain for at least 72 hours. Swim away from the stream mouth for the best water quality. The windward side gets frequent rain showers, so check the forecast before your visit.