Question 1

Is Ko Olina safe to swim today?

Accepted Answer

Ko Olina's four man-made lagoons are generally among the safest swimming spots on Oahu. The lagoons are sheltered from open ocean waves and are far from major stream runoff. Check this page for current DOH advisories. After heavy island-wide rain, even Ko Olina can be temporarily affected.

Question 2

Which Ko Olina lagoon is best for swimming?

Accepted Answer

All four Ko Olina lagoons have similar water quality. Lagoon 1 (Kohola) near the Four Seasons is usually the least crowded. Lagoon 2 (Honu) fronts the Aulani Disney Resort and is popular with families. Lagoon 4 (Ulua) is the most public-accessible with the largest parking area. Water quality conditions are essentially the same across all four lagoons.

Question 3

Is the water at Aulani Disney Resort clean?

Accepted Answer

Yes, the Aulani Disney Resort sits on Ko Olina Lagoon 2 (Honu Lagoon), which has consistently good water quality. The west side of Oahu receives less rainfall than the windward coast, and the man-made lagoons are designed to circulate ocean water. Ko Olina is one of the safest beach swimming areas on Oahu.

Question 4

Is it safe to swim at Ko Olina Lagoons?

Accepted Answer

Ko Olina Lagoons have a Moderate bacteria risk rating (2 out of 5). The four man-made lagoons have limited water exchange compared to open beaches, which means bacteria can persist longer after storms. Under normal conditions, DOH monitoring shows acceptable levels. No major stream runoff feeds into the lagoons.

Question 5

Is Ko Olina affected by the Waimanalo Gulch Landfill?

Accepted Answer

The Waimanalo Gulch Landfill is located directly behind Ko Olina. In 2010-2011, severe storms caused contaminated stormwater, leachate, and medical waste to discharge into the ocean, closing Ko Olina lagoons. An EPA consent decree required infrastructure upgrades, which were completed, and the decree was terminated in August 2023. The risk of a repeat event is lower now but the landfill remains operational.

Question 6

How do Ko Olina's man-made lagoons work?

Accepted Answer

The four lagoons were built in the 1980s with breakwater openings that allow ocean water to flow in and out with the tides. This natural flushing keeps the water clean under normal conditions, though the enclosed shape means water circulates more slowly than at an open beach.

Question 7

Is Electric Beach near Ko Olina safe to swim?

Accepted Answer

Electric Beach (Kahe Point) is near Ko Olina but is a separate open-ocean beach. The warm water discharge from the adjacent power plant is clean cooling water, not contaminated effluent — it actually attracts marine life and is a popular snorkeling spot. Electric Beach has different water quality characteristics than the enclosed Ko Olina lagoons.

Question 8

Which Ko Olina lagoon is the cleanest?

Accepted Answer

All four lagoons share similar water quality since they use the same ocean flushing system. The lagoons closest to the open ocean inlet may have slightly better circulation. DOH monitors the lagoons as a group and typically issues advisories for the entire Ko Olina area when needed.

Question 9

Is Ko Olina the same as Disney Beach?

Accepted Answer

Ko Olina's four man-made lagoons are sometimes called Disney Beach because the Aulani Disney Resort is located at Lagoon 1. All four lagoons share the same ocean water and similar water quality conditions.