A recent editorial called for prioritizing green remedies and ecosystem resiliency while mitigating flood risk in the Ala Wai watershed (“Craft a holistic Ala Wai solution,” Star-Advertiser, Our View, April 20). It requires an integrated natural resource management plan for the Waikiki ahupua‘a, historically a wetland. Residents requested this all along. Also, University of Hawaii graduate planning students in 2001 were already advocating the integration of indigenous Hawaiian land and resources management techniques.

Available now is a useful tracking spreadsheet by the U.S. Army Corps of Engineers (ACE) listing about 200 measures that are “under consideration” or are already “screened out” when they are not within its authority or study scope. But this relegates to an afterthought essential environmental design measures.

An integrated ecological and flood control design solution would have different configurations than the one focusing on flood alone. Instead, a “co-design” approach engages federal, state, county and community partners in collaboration at each step of the process.

I hope officials populate and share the 200 measures with their own assessments by revealing in the spreadsheet which agency would be the leading one, and which other would be listed in a supporting role. A good example is how the Ala Wai Watershed Collaboration describes proposed linked measures, such as ones for the Ala Wai Golf Course and the Ala Wai Canal.

An appropriate engineering solution addressing simultaneously overlapping risks — potential imminent riverine flood and tsunami, and sea level rise — has a quite different design from one addressing only riverine flood. The same applies to ecosystem restoration — inclusive of pollution abatement, water quality, debris management and channel cleanups, invasive species control, forest management, coastal flooding and cultural recreational uses.

Evaluation should not be limited to what is permitted by the authority of ACE. There are other entities involved: the Environmental Protection Agency and several presidential executive orders requiring compliance with protection and enhancement of environmental quality; federal flood risk management standards; protection of wetlands; invasive species; environmental justice; and protection of children from environmental risk and safety risk. In fact, Hawaii’s 1st Circuit Court in 2019 correctly reminded us that the state needs an acceptable environmental impact statement (EIS) to commit funds.

Good documentation allows each organization to clarify its kuleana, what they can accomplish or not and propose additional resources needed from funding authorities. Agencies should have institutional memory and document what was done in the past for this watershed. “Complying by referencing” previous studies and then updating what is missing can help the EIS be done more efficiently.

The Ala Wai Watershed Analysis already in 2003 recommended detailed ecosystem restoration measures. The Ala Wai Canal Flushing System and the Ala Wai Golf Course Detention System engineering studies done previously designed a multipurpose wetland for sediment, filtration, irrigation and vegetated marsh to greatly improve water quality. This is key for flood protection of Moiliili and Waikiki because it diverts storm waters from the Manoa-Palolo Canal right into the golf course.

The ocean water pumped up at Kapahulu into the Ala Wai Canal east end keeps its water moving and clean. These two measures make feasible the second ocean outfall at Kapiolani Park, well away from Waikiki.

Most importantly, after three decades, we deserve a planning framework that explicitly addresses how environmental justice serves all the affected neighborhood, including McCully-Moiliili, in terms of risks, flood reduction and ecosystem restoration. This would move forward the aspiration of the recent editorial.

Luciano Minerbi is a professor emeritus of urban and regional planning at the University of Hawaii-Manoa.