US Forest Service and ASU present ‘Ridge‑to‑Reef’ decision‑support tools to Hawaii County councilors; members press on data, AI and policy use

HILO — Researchers from the U.S. Forest Service and Arizona State University presented a Ridge‑to‑Reef decision‑support project to the Hawaii County Communications, Reports and Council Oversight Committee on Oct. 1, describing spatial tools intended to help land managers prioritize interventions for wildfire, invasive species and wastewater‑related reef contamination.

Gina, a U.S. Forest Service postdoctoral ecologist leading the visit, said the project covers three study geographies on Hawaii Island and integrates ecological data, stewardship mapping and community values into a spatial decision model. “Our core questions really are how and at what scale we can do restoration for these different topics, ridge to reef, fire development, climate change, invasive species across these three geographies,” she said.

Presenters described a South Kona groundwater flow and transport model aimed at estimating nitrate and phosphorus loads from on‑site sewage disposal systems and linking subsurface concentrations to nearshore reef exposure. A presenter cited Miloli/Papa Bay as an example where groundwater nitrate concentrations reached roughly 20 milligrams per liter in localized areas and said submarine groundwater discharge data will help quantify how much contaminant actually reaches reefs.

On wildfire and vegetation, Jennifer Olguin summarized a fire‑exposure model and the potential for “shaded fuel breaks” — planting canopy to reduce fine fuels — while noting maintenance, water availability and local feasibility constraints in leeward, arid zones. Jasper Ocean (Arizona State University) described sediment mobilization dynamics and recommended measuring stream outlet fluxes during storms to quantify the fraction of mobilized sediment that reaches the reef. “High intensity rainfall ... will mobilize sediment on the landscape that basically exceeds the capacity of the bare ground to absorb the rain,” he said.

Council members asked detailed questions about model methods, data inputs and future applications. Councilmember Evans asked whether the project intends to use artificial intelligence or machine learning in linking layers and scoring alternatives; Paul Hesberg said increased computing power makes machine‑learning components feasible for pattern detection and decision feedback. “The thing that's new is that the machine learning and AI algorithms have been around for 40 years. What's changed is computing power,” he said.

Councilmember Connie Lee Kleinfelder urged the team to include Puna in future materials and asked whether windblown sediment had been measured; presenters said wind transport is plausible but magnitude relative to fluvial sediment is uncertain and recommended local measurements to clarify the contribution.

Several councilors cautioned that if the county were to rely on model outputs for regulation or mandates (for example, denitrification requirements), the underlying data models must be robust, transparent and defensible. Presenters said they are working with local partners, improving vegetation and climate data layers and incorporating indigenous agroecological scenarios and cultural mapping into tool development.

Councilmember Kimball moved to close file on Communication 1058; the committee voted to close the file by voice vote. The chair announced six members in favor with three excused. Presenters and staff will continue follow‑ups with county planning and other departments during the team’s visit.