By Ms. Bryanna Poulin (USACE)September 12, 2019
MAUI, HAWAII-- The U.S. Army Corps of Engineers-Honolulu District (USACE) civil works branch teamed with the USACE Committee on River Engineering (CRE) July 19 to Aug. 2 to revisit two civil works project actions and evaluated the potential for future repairs during the 85th meeting of the USACE CRE.
Committee members are full-time USACE civilian employees and subject matter experts (SME) who supply advisory consultation services. While on Maui the group provided their input for Honolulu District's Iao Stream Flood Control Project (FCP) General Reevaluation study and the West Maui Watershed study.
Coordination for the committee to meet and evaluate the Honolulu District projects took nearly a year.
"The committee supports Districts across the nation working in urban and rural environments, large rivers, and small streams," John Remus II, CRE chairperson said. "In addition, we assist District's in dealing with issues ranging from navigation, bank stabilization, dam removal, and environmental restoration."
Since the project completion in 1981, Iao Stream FCP locally known as the Wailuku River has seen numerous floods events that severely eroded the streambed and critical portions of the Corps-constructed levees in the FCP. Following a another flood event in Sept. 2016, the District completed emergency repairs to most of the right bank of the FCP levee, but recognized the need for additional recommendations on project improvements, and requested CRE assistance to evaluate the flood control project.
"The technical committees bring their expertise in either assisting the District in initiating a project (West Maui), or act as a sounding board during project development (Iao Stream)," Remus said.
Almost 40 miles west of Iao Stream, terrestrial sediment discharging from the West Maui watershed is a well-known stressor to local coral reef ecosystems. The adjacent offshore reefs have lost nearly one-fourth of living corals in the last 13 years. Over the last decade as part of the West Maui Ridge to Reef initiative, Honolulu District has been an actively compiling the West Maui Watershed Study in partnership with the State of Hawaii and local agencies. The study's goal is to contribute to the restoration, enhancement and resiliency of West Maui coral reefs and near shore waters through the reduction of land-based pollution threats. The Ridge to Reef initiative builds on already established efforts underway and leverages resources across a number of agencies and community groups to implement actions to reduce one of the key sources of reef decline -- land-based sources of pollution.
The District civil works branch team asked for the committee's recommendations addressing the in-stream erosion as the primary source of sediment contributing to the degradation of near-shore coral reefs. Honolulu District Civil Works Team Lead and Hydraulic Engineer Jessica Brunty and Project Manager Jessie Paahana led the group on a site walk in the watershed for analysis.
"By providing technical advice like data collection, modeling recommendations, or other alternatives to consider, the CRE's goal is augmenting the expertise the District already has," Remus said.
The District and CRE collaboration efforts are contributing to the restoration, enhancement, and resiliency of coral reefs and near-shore waters by identifying solutions to reducing sediments carried in streams from the summit of Pu'u Kukui in the West Maui Mountains to the outer reef.
One benefit of the partnership is a positive impact on the community.
"The public benefits anytime an agency can get a head start to marshal and focus their expertise addressing a challenging problem, without having to reinvent the wheel," Remus said.
Another benefit in the collaboration is CRE and Honolulu District engineers sharing knowledge, developing new skills, and creating new ideas by brainstorming with each other and offering input and feedback.
"The goal isn't the committee transferring knowledge, but how the CRE and the District learn from each other," said Remus. "I have learned something on each CRE mission, that I'm able to apply somewhere else."
Having more than two decades on the CRE committee, Remus has seen how diversity in personnel experience affects the CRE.
"The committee is so diverse that the amount of "brainpower" and creativity results in practical solutions the District can use to further the project."
The CRE and Honolulu District civil works team discussed various alternatives and future options.
"I feel the Honolulu District has done a good job of identifying alternatives for the (two) projects. The devil is in the details, but it's important to remember in those big problems are also big opportunities."
In the final report highlighting the site visits, Honolulu District Civil Works team lead Jessica Brunty said, "The committee provided the District with valuable insight on two critical projects. By sharing their perspective, the District has improved its ability to conduct flood and erosion studies and effectively deliver integrated water resource solutions to our local project partners."