Hāna Bay

Hāna Bay is a calm, family-friendly swim spot during dry windows but receives stream runoff from Hāna Stream and graywater from the small-boat harbor. The latest Surfrider BWTF sample measured 213 MPN/100mL enterococcus — above the 130 BAV threshold. The Hawaii DOH does not routinely test this beach.

Hāna Stream empties into the bay's north end, draining a wet windward valley that gets 80+ inches of rain a year. Stream water carries sediment, animal waste, and bacteria from the upstream watershed. Surfrider's BWTF measures the Kaholopo‘o Rivermouth (just south of the bay near Kōki Beach) at 135 MPN/100mL — a typical East Maui river-mouth reading.

Hāna small-boat harbor sits at the bay's south end. Harbors concentrate fuel, graywater discharge, and wildlife activity that elevate bacteria in the surrounding water. The bay's sheltered geometry — its strength as a swim spot — also means contaminants flush out more slowly than at open beaches.

River mouths and sheltered harbors are the two strongest predictors of elevated bacteria at any Hawaii beach. Hāna Bay has both, which puts it in the moderate-risk range even under dry conditions.

The Hawaii Department of Health does NOT maintain a monitoring station at Hāna Bay. East Maui's wet, remote coast has few DOH stations overall — most state testing concentrates on the South Maui resort coast (Wailea/Kīhei) and the Lahaina-Kā‘anapali area.

The community-tested readings on this page come from the Surfrider Foundation Blue Water Task Force, a volunteer-led monitoring program run by the Maui chapter. BWTF samples Hāna Bay roughly monthly using the IDEXX Enterolert method (MPN/100mL), and compares results against the same 130 Beach Action Value DOH uses statewide.

See our overview of citizen water-quality testing in Hawai‘i for how BWTF data fits with DOH coverage and the methodology behind the readings.

The calmest, clearest conditions at Hāna Bay come during dry windows in May–September. The natural breakwater shelters the bay from open-ocean swell year-round, but stream-driven turbidity is dramatically lower in summer than after winter storms. The black-sand beach is wide enough for shade-seekers and the gradual entry is forgiving for kids.

Stay near the central beach. Avoid the immediate area around the stream mouth at the north end (where bacteria readings concentrate) and the harbor at the south end (where boat-related inputs gather). The middle of the crescent has the cleanest historical readings and the calmest conditions.

Hāna Bay Beach Park is in the center of Hāna town off Keawa Place, about 52 miles and 2.5–4 hours' drive from Kahului Airport on the Road to Hāna (Hawai‘i Route 360). Free parking, restrooms, picnic tables, and a small store. Cell service is limited or absent — download maps and any reading material before the drive.