Changes to Ala Wai flood control project increase costs and add pump station

The U.S. Army Corps of Engineers has made dramatic changes to its Ala Wai Flood Risk Management Project, which increase costs and add a four-story pump station to the historic Ala Wai Canal, where controversial walls and berms already are planned.

The USACE is holding four virtual scoping meetings over the next four Saturdays to get input on the changes, which Jeff Herzog, project manager for the corps’ Ala Wai flood control project, says focus on evacuating water in the upper reaches of the watershed valleys without detaining it, lessening the impact on residential properties and natural streams.

The project stalled last year after staggering pushback from the community, which included the formation of a Honolulu City Council permitted interaction group, protests and even a lawsuit. But it’s moving ahead again after USACE obtained federal approval in August for an Engineering Documentation Report that makes design changes and adds new features.

Herzog, who spoke at the Waikiki Neighborhood Board meeting Tuesday, said USACE’s new plan presents alternatives to a 2017 plan. The new proposal, outlined in the EDR, conveys flood waters through the Manoa watershed and Ala Wai Canal, and addresses potential effects associated with redirecting flood waters at Manoa Marketplace.

It consolidates two pump stations into a single pump station at the Ala Wai Golf Course and proposes eliminating six detention basins in the upper watershed. It adds a Woodlawn bypass feature to the Manoa Marketplace to divert water away from the University of Hawaii at Manoa. The proposal includes a new bypass culvert for Makiki Stream, which adds a new promenade area near the Hawai‘i Convention Center. It also makes modifications to previously authorized project features at Kanewai and Hausten Ditch, Ala Wai Golf Course and Ala Wai Canal flood barriers with pump stations.

“We would encourage everybody to at least attend one session over the next four weeks,” Herzog said. “We’re looking at one piece of the puzzle. It’s important to involve the community as well as our partners at the state and the city and county to ensure that we can make this project holistically acceptable to the community. We’ll present some ideas and take back more ideas and present additional opportunities some time in February 2021.”

Herzog said community input was included in the EDR. It also will be incorporated into a supplemental environmental assessment, which USACE expects to release in February, and is required under the National Environmental Policy Act and Hawaii Environmental Policy Act.

By the time the supplemental environmental assessment is complete, Honolulu Mayor Rick Blangiardi should be in office, and will be asked to consider signing a project partnership agreement with USACE obligating the city to maintain the project’s infrastructure.

Almost everyone understands the need to minimize flood risks in the Ala Wai Watershed, which is approximately 19 square miles and extends from the Koolau Mountains to Mamala Bay. The USACE estimates that a 100-year flood in the watershed, which includes Waikiki, could impact 1,358 acres, damage 3,000 structures and cost more than $1.14 billion.

But there’s been strong debate on the best way to do it. Critics are voicing fewer objections to the project’s latest changes. However, some resistance is still expected.

Honolulu City Councilwoman Ann Kobaysahi isn’t sold on adding a four-story pump station to the Ala Wai Canal or surrounding portions of the canal with large walls. She hopes USACE will instead consider incorporating an August 2020 proposal from the city’s technical consultant Oceanit into its plan.

Oceanit’s recommendation, Subsurface Watershed Inundation Flow Technology, uses two 12-foot tunnels — one for Manoa and one for Palolo — “to remove water from the upper watersheds, bypass the lower watershed and the Ala Wai Canal, and discharge directly into the ocean.”

Kobayashi said the city spent $100,000 in 2019 to hire Oceanit to work with the community to come up with alternatives to the USACE plan. After that process concluded, Kobayashi said, the city put out a request for proposals and Oceanit was awarded $500,000 to develop designs executing the community’s vision.

“The most troubling thing for many in the district, including the paddlers, are the walls around the Ala Wai Canal and the huge, four-story water pump,” Kobayashi said. “If we do this tunnel thing it’s about the same cost and there won’t be all this ugliness. We are working to have Oceanit meet with the Army Corps to come up with a plan that’s a combination of the two proposals.”

Sidney Lynch, president of Protect Our Ala Wai Watersheds, an organization that initially sued the city and state to stop the project, said the group is pleased “that USACE has been able to reevaluate their original plan, realize the upstream detention basins were not realistic and come up with the EDR.”

“We ask that the public be shown to-scale drawings and 3D modeling of the revised elements in place as it is difficult for the layman to visualize from figures,” Lynch said. “We also hope that USACE will be able to incorporate some of the city’s Oceanit SWIFT plan to address the areas of flooding that the USACE EDR does not cover.”

Dave Watase, a vocal critic of the 2017 plan, said “there are many problems with the Army Corps new plan and many of the new elements were done without community involvement.”

“Aside from taking out the detention basins in the upper valleys, the Army Corps basically ignored all community-generated alternatives,” Watase said. “I’m still trying to get them to remove the Kanewai multipurpose detention basin.”

Supporters say they are thankful that the EDR revives the circa-1999 project. Among their biggest fears is that the next big weather disaster could catch Oahu flat-footed, risking life and racking up billions of dollars in damage, especially to Waikiki, the epicenter of the state’s tourism economy.

Waikiki Neighborhood Board Chairman Bob Finley said the project benefits all who live in Waikiki.

“The elevators don’t work well when they are underwater,” Finley said. “Your streets don’t work well when they are flooded. I’m sure the end result of this will be a safer Waikiki.We look forward to February, when we see the project pretty much in its final form.”

Waikiki Neighborhood Board member Jeff Merz said officials must work to preserve federal funding, especially given the coming administration change.

“We need to show Washington that we are behind this project and we deserve it,” he said.

Under previous designs, the Army Corps said the project was expected to cost $345 million, with the state agreeing to pay $121 million and federal dollars covering the rest. The new plan is estimated to cost approximately $376 million and includes a $48 million contingency.

Herzog reassured Merz that federal funding is still in place and the USACE has been directed to keep moving ahead unless told otherwise.

“We will keep the foot on the gas because it’s absolutely important that we deliver this project for the community,” he said.

It’s less clear if the state — which is expected to run more than a $1 billion deficit over the next several years — will still be able to afford the project’s local share without taking on more debt or exploring alternative funding sources.

SCOPE IT OUT

The community is invited to participate virtually in public forums about the Ala Wai Flood Risk Management Project. Log into usace1.webex.com/meet/jeffrey.a.herzog or dial 1-844-800-2712; Access Code: 199 126 8738#; Security Code: 1234#.

Saturday: Environmental Impacts scoping meeting, 8-10 a.m.

Nov. 21: Environmental Impacts scoping meeting, 8-10 a.m.

Nov. 28: Design and Engineering Forum, 8-11 a.m.

Dec. 5: Design and Engineering Forum, 8-11 a.m.

Anyone wishing to present project concepts or engineering solutions at forums should contact Jeffrey A. Herzog at jeffrey.a.herzog@usace.army.mil or Cindy Acpal at cindy.m.acpal@usace.army.mil before 4 p.m., Monday, for a presentation time assignment. Questions and feedback also can be emailed to: AlaWaiFloodProject@usace.army.mil.

Source: USACE