News that Honolulu could face paying out more than $11 billion to complete a flood-control project through watersheds feeding into the Ala Wai Canal is staggering. That’s a tenfold rise in potential costs, compared to a working estimate of $1.0675 billion issued in November 2023. That astronomically high bill threatens to delay or even halt the project — putting it “out of reach,” as Honolulu Mayor Rick Blangiardi told attendees, including Gov. Josh Green, at a Feb. 27 hotel industry event.
However, wholesale inaction is not an option: Communities, infrastructure and natural areas are vulnerable to devastating storm damage and flooding in the Ala Wai watersheds, as is Waikiki, which could face billions of dollars in damage if waters overflow the one-ended canal. As Blangiardi stated, “Given recent disasters that were once considered unthinkable — the Maui fires, COVID, Red Hill — it would be naive to simply hope something bad does not occur.”
It’s somewhat misleading to say “project costs” have ballooned — and that provides some room for hope that alternative strategies to control expense can be identified. The cost of the flood control project itself — constructing flood walls, berms and floodwater detention basins — continues to be estimated at around $775 million, says the Army Corps of Engineers. Adding in “nonstructural mitigation measures” brings the total to $1.0675 billion.
The jaw-dropping $9 billion in additional costs that Blangiardi references comes from exposure to liability — potential payouts if the project itself causes repeated flooding or other permanent damage to property.
At least we think that’s it. Blangiardi and the city declined to elaborate on specifics of the mayor’s concern about costs, or to confirm that potential liability is the concern. That’s our first point of criticism. The public must be kept abreast of new developments or discoveries of risks, as taxpayers certainly have a stake in considering issues that could cost the city billions of dollars.
The legal case that may affect the city’s exposure to liability was fought over a multistate flood control project along the Missouri River. Similarities to Honolulu’s project risks will drive necessary next steps. It’s critical that city, state and federal officials address this issue with additional preventative measures, if available, or alternative flood-control strategies. Federal aid must be provided for this “need to have” project, if necessary. And the city must press on.
Concerns over flood damage have also risen in recent years. A 2019 “Hawaii Infrastructure Report Card” developed by the American Society of Civil Engineers warned of increasing threats from rising seas and severe storms, and singled out the Ala Wai Canal as a high-priority project. “A 100-year (1% probability) event would result in damages to more than 3,000 structures in the watershed, with total damages exceeding $1 billion,” the report states.
In 2018, Oahu was hit by a severe April storm, and sideswiped by heavy winds and rain in August as Hurricane Lane passed by, dropping unprecedented amounts of rain. In the Ala Wai watersheds, flooding closed roads and dumped disturbing quantities of runoff soil, organic matter, contaminants and waste into the Ala Wai and, from there, the ocean. It would serve residents well to remember this close encounter with disaster, which also caused fires on Oahu and in West Maui: After storm-whipped 2023 fires devastated Lahaina, Maui County was harshly, and rightly, criticized for failing to shore up its defenses after the 2018 close call.
There’s no responsible leeway to walk away from the Ala Wai flood control that’s needed. Blangiardi said the city will continue seeking “practical solutions that can prevent the very real risk of a catastrophic flood, while also being fiscally responsible” — and so it must, with an appropriate sense of urgency. The more delay in this project, the higher the actual cost will grow — and the longer the city will remain exposed to disastrous damage.
