A $3 million intergovernmental study is planned to design measures to prevent potential Wailupe Stream Watershed flooding.

The Wailupe Stream is the last major valley stream in East Honolulu that’s not fully lined with concrete — one of 10 such streams that drains its watershed into the roughly 7-mile-long Maunalua Bay.

But unlike the nine other tributaries that flow into the bay, the stream that flows in and around communities like Aina Haina remains in a largely natural state.

Due to this fact, area residents and city officials say the stream is historically prone to flooding events. That includes a flash flood in 2018 that destroyed three homes and damaged more than 150 others in the area of the stream.

As drafted under Council Resolution 204, the flood control project — to be undertaken via a formal agreement to be signed by the city Department of Design and Construction and U.S. Army Corps of Engineers — includes “all activities and tasks required to identify and evaluate alternatives resulting in the preparation of a decision document that recommends a coordinated and implementable solution for flood risk management for the Wailupe Stream Watershed,” the resolution states.

As proposed, the Wailupe flood study would cost the city about $1.5 million. The city would pay the Army Corps of Engineers 50% of the estimated $3 million project.

To that end the city has identified $500,000 for this “decision document” — funds that were appropriated under the city’s 2024 capital improvement program budget, the resolution states. It indicates that the remaining $1 million would be programmed in the city’s 2026 fiscal year CIP, which does not take effect until July 1.

But the flood control project has drawn support and opposition.

At a recent City Council meeting, Aina Haina resident Anson Rego, who supports the resolution, recalled the time the Wailupe Stream flooded in April 2018, causing “substantial damages and near loss of life.”

Since that flood, Rego said, no regular city maintenance has occurred along the stream that his property adjoins.

“We’ve lived on the stream for over 30 years; maintenance of Wailupe Stream has been nonexistent for decades,” he said. “Today, I understand, it’s less than 10 persons to maintain the entire island of Oahu for all the streams, and quite frankly, Wailupe Stream has only been done once in the 5-1/2 years since the flooding itself.”

“Therefore, maintenance itself needs to be studied,” he added.

Chris Cramer, a co-founder of the Maunalua Fishpond Heritage Center who also lives near Wailupe Stream, said the Council should not commit to any flood study until the public has been better informed.

“I would just like to ask that this resolution include the fishing community and the Native Hawaiian community,” he told the panel. “We’ve seen the destruction that has happened, but we don’t want to throw everything out and destroy the stream like has been done to all the other streams in Maunalua Bay.”

Moreover, Cramer said, the city continues to allow residential housing to be built next to flood-damaged areas of Wailupe Stream.

“And the city approved a ‘monster home’ right where that destroyed section was,” he said. “And they got two more (homes) on the way. So building in the setback is something that needs to be addressed before you are looking at these other options.”

“You’ve got to use common sense, which is not approving development right in the stream setback,” he said. “It’s basic common sense.”

Still, city officials say Resolution 204 only looks to set up a working agreement with the military.

“This project where it stands right now is even before the planning effort,” DDC Director Haku Milles told the Council on Sept. 4. “The project that we’re working (toward) right now with the Army corps is to move into a planning portion so that we can engage the community and focus on what the scope of work should be and what the focus should be in mitigating potential flood hazards.”

Michael Salyer, the Army Corps of Engineers’ chief of public civil works for the Hono­lulu district, also appeared at the meeting.

“We have been listening, my staff has been listening, for the concerns on the Wailupe project,” he said. “The corps has evolved a lot over 20-something years. … We’re here to show our support with our partners to try to advance, to get into this study with a feasibility cost-share agreement and to work with the local communities.”

Salyer said the corps “is working hard to include our Native Hawaiian organizations and all of the stakeholders and the local residents that we think is very important to be a part of that process.”

Council chair Tommy Waters, whose Council District 4 spans East Honolulu, urged the Army Corps of Engineers to be mindful of the public as it conducts its “study to mitigate the hazards of a flood.”

“And you’ll give us your commitment that you’ll work with the community and let them participate meaningfully in the study when determining what is the appropriate thing to do with Wailupe Stream, right?” Waters asked.

“Yes, sir,” Salyer replied, “that is paramount to having this study and this project go forward.”

Council member Andria Tulpola asked Salyer, “When do you talk to the community?”

“I think just for clarity, is it before, during or after?” she asked. “And in what ways does that happen? Is it just emails, calls, or is there a community meeting that you convene?”

Salyer replied, “As soon as we sign the agreement, we are able to tackle it with some resources.”

“We’ll be putting together an extensive outreach and communication plan,” he added. “That communication would occur as soon as we get going, during and afterwards, all along that study.”

Waters later requested the Army Corps of Engineers to stay in contact with his office “because I can reach out to the community and host community meetings as well.”

Ultimately, the Council voted to adopt Resolution 204.