Field Notes from Palau: Measuring Elevation to Turn Flood Stories into Actionable Indicators

Coastal flooding in Palau is already affecting daily life—overtopping roads, disrupting access, and threatening critical and culturally important places. In partnership with Pacific RISA, Hawaii Sea Grant and the University of Hawaiʻi Sea Level Center (UHSLC), this work supports partners in in developing practical, place-based flood indicators that translate sea level and tide information into clear, decision-relevant insights for locations identified as vulnerable.

Over 10 days in January, Coastal Adaptation Specialist Moehlenkamp helped support field visits where a team collected 120 high-accuracy elevation measurements across Koror, Babeldaob, and Peleliu to support flooding threshold analysis. These measurements help link what communities observe on the ground with what tide gauge records show over time—so communities and agencies can better understand how severe flooding has been at specific places in the past, and how the frequency and depth of those events are likely to change as sea levels continue to rise.

From interviews to a priority site list

This field data collection effort was built on a stakeholder-driven process. An initial list of flood impact locations was compiled through interviews and meetings with community members, and stakeholders across the NGO, private, and government sectors. Those conversations identified roads, causeways, schools, taro fields, cultural sites, and other places where flooding creates real impacts. That list was then refined in collaboration with the Office of Climate Change (OCC) and the Palau Automated Land and Resources Information System (PALARIS) focusing on priority sites where elevation data could most directly support flood thresholds and locally usable indicators.

Field visits with local coordination and context

With support from the OCC, Coastal Adaptation Specialist Moehlenkamp visited sites and helped coordinate on-the-ground engagement. At many locations, the team met with state governors and/or state Protected Areas Network (PAN) coordinators, who guided them to the precise points to measure, and who also shared valuable context on flooding history and community impacts. These brief site meetings helped ensure the elevation measurements are not only technically accurate, but also locally meaningful and directly useful for the communities most affected.

What these measurements enable: localized flood indicators

Unlike broad flood risk assessments, this approach is designed to produce highly localized results. By linking high-accuracy elevation measurements at flood-prone sites with long-term tide gauge records, the analysis can evaluate a specific location—such as a road segment, school, or other critical site—and estimate:

• Historical flooding frequency (how often water levels likely exceeded a site’s flood threshold)
• Severity (how far above the threshold water levels reached during exceedances)
• Future changes in frequency and severity under different sea level rise scenarios

This level of detail can support both community and government decision-making, strengthen national adaptation planning, and inform updates to regional planning products and assessments.