by Paula Moehlenkamp
Coastal flooding in Palau is already affecting daily life – overtopping roads, disrupting access, and threatening critical and culturally significant places. A partnership between the Pacific Research on Island Solutions for Adaptation (Pacific RISA) program, Hawaiʻi Sea Grant, and the University of Hawaiʻi Sea Level Center (UHSLC) is supporting efforts to develop practical, place-based flood indicators that translate sea level and tide information into clear, decision-relevant insights for locations identified as susceptible to flooding.
During earlier sector-based climate services workshops in Palau, local stakeholders highlighted a need for more applied, locally relevant information on flooding, such as tools that connect sea level and tide data to impacts on the specific places people care about, such as roads, schools, clinics, neighborhoods, and taro fields. Palau’s Development Plan and Voluntary National Review (VNR) similarly call for science-based responses to flooding that is already disrupting vital community assets and services.
As a coastal adaptation specialist with Hawaiʻi Sea Grant who was trained as an oceanographer, I have focused on bridging that scale gap. Much of the available sea-level rise information remains too coarse to inform site-level decisions. My project addresses that need by linking coastal oceanographic datasets with high-accuracy, on-the-ground elevation measurements and community observations to produce decision-ready flood thresholds aligned with local priorities.
10 days, 120 elevations
Over 10 days in January, I collected 120 high-accuracy elevation measurements across Palau, in Koror, Babeldaob, and Peleliu, to contribute to a flooding threshold analysis. These measurements help link what communities observe on the ground with what tide gauge records show over time, so that communities and agencies can better understand how severe flooding has been at specific locations in the past, and how the frequency and depths of such 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 from 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. These conversations identified important assets across Palau where flooding is already affecting daily life, including roads, causeways, schools, taro fields, cultural sites, harbors, and docks. 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 inform flood thresholds and locally usable indicators.
Field visits and community engagement
With support from the OCC, we visited sites and helped coordinate on-the-ground engagement. At many locations, we met with state governors, state rangers, and Protected Areas Network (PAN) coordinators, who guided us to precise points to take measurements and 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.
Deriving localized flood indicators
Unlike broad flooding 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 important metrics, such as:
- historical flooding frequency: how often water levels likely exceeded a site’s flood threshold;
- severity: how far above the flood threshold the water levels reached during high-water events;
- future changes in frequency and severity under different sea-level rise scenarios.
This level of detail in flooding analysis can support community and government decision-making, strengthen national adaptation planning, and inform updates to regional planning products and assessments.
About the author:
Paula is an interdisciplinary coastal adaptation specialist with the Pacific RISA program. Her work focuses on coastal climate adaptation and sea-level impacts in the Pacific Islands, with an emphasis on bridging scientific understanding of coastal flooding and sea-level variability with community-informed knowledge, values, and priorities. She is passionate about advancing actionable, locally relevant adaptation planning that strengthens flood resilience across island communities.