Frequently Asked Questions

I heard there is an Army Corps project for the Ala Wai?

The US Army Corps of Engineers has been involved in the Ala Wai watershed since 1992, culminating in a Feasibility Study and EIS of a flood mitigation project in May 2017 called the “Ala Wai Canal Project”. The preliminary project designs include a flood wall around the Ala Wai canal, retention basins upstream and on the Ala Wai Golf Course, as well as in-stream debris catchment features. In July 2018, Congress appropriated $345million in funding (65% federal and 35% local cost share), allowing the project to move into its next phase of negotiating funding with State and City & County. More information can be found under “Current Projects” on our homepage.

Why is the Ala Wai Canal so polluted?

The pollutants come from a number of sources: debris natural erosion of sediments from the mauka forest (made worse by invasive species and eroding streambanks in the urban areas), pathogens from feral pigs and cesspools, chemical pollutants from fertilizers and pesticides, heavy metals from cars (break pads, tires, and exhaust gases), and plastic pollution from littering. The relatively stagnant waters, especially in the Kapahulu end of the canal, create conditions where pathogens and pollutants can accumulate. As early as the 1930s, the public was advised not to swim in the canal. Learn more about the efforts to clean the canal in the Community Restoration and Litter Prevention & Pickup sections on our homepage.

Why is the Ala Wai Watershed so vulnerable?

Vulnerability comes from the combination of hazards and our exposure to them. The Ala Wai watershed faces many hazards, and in particular hurricanes, storm surges from the ocean, and downstream flooding caused by rain. All of these hazards are made worse by climate change. Urbanization also makes these hazards more dangerous, because channelizing our streams with concrete, paving over the majority of surface area with roads, sidewalks, parking lots, and driveways prevents water from soaking into the ground and allows it to flow down stream faster, causing flash floods. Improving resilience means both mitigating the damage that these hazards pose, and reducing our exposure to them. Learn more in the Disaster Resilience section of our homepage.

Which ahupuaʻa is the Ala Wai Watershed in?

Most of the watershed is located in the Waikīkī ahupuaʻa, but the Makiki area is in the Honolulu ahupuaʻa. The watershed boundaries became different from the ahupuaʻa boundaries when the Ala Wai canal was dredged and Mānoa, Pālolo and Makiki streams redirected to flow into the canal.

Why does the Ala Wai canal have a dead end?

The Ala Wai canal was initially designed to have a second opening to the ocean, but it soon became clear that this would flush sediments and pollution right onto the Waikīkī Beach area, so that opening was never completed. The possibility of breaking through to create a second opening was studied both by DLNR 1992-1995 and UH & OEQC 1976, but no plans were ever made.

What’s the difference between the Ala Wai Watershed Association and the Ala Wai Watershed Collaboration?

The Ala Wai Watershed Association was founded in 1996 and is a non-profit organization that does volunteer events and conducts streambank restoration and research. The Ala Wai Watershed Collaboration is not an incorporated organization, but a group and network of stakeholders, and the Ala Wai Watershed Association is one of its members.