A collection of datasets from various Dutch institutions to demonstrate a Spatial Data Infrastructure built on Portolan.
Boundaries of 1,545 flood retention areas (bergingsgebieden) in the Netherlands — areas where water can be temporarily stored during high water events. These are part of the Dutch flood risk management system, which uses controlled water storage to reduce peak water levels and prevent uncontrolled flooding.
Some areas are legally established (wettelijk vastgesteld) under Dutch water law; others are designated but not yet formally codified. The dataset includes storage capacity figures for some areas, though many have null values.
Provider: Rijkswaterstaat (Directorate-General for Public Works and Water Management) License: Public domain (Dutch government open data)
The data is a GeoParquet file in EPSG:28992 (Amersfoort / RD New). Use DuckDB with the spatial extension.
One Mapbox GL v8 style is available for interactive map visualization via the PMTiles file.
Style files are Mapbox GL v8 JSON with relative PMTiles source paths. They can be used with MapLibre GL JS, OpenLayers (via ol-mapbox-style), or any Mapbox GL v8-compatible renderer.
styles/default.json — Light blue flood retention area fills with darker blue outlines. Shows the spatial distribution of water storage areas along Dutch rivers and coast.Style files are at: https://data.source.coop/cholmes/portolan-nl/rijkswaterstaat/bergingsgebieden/styles/
bergendvermogen is often null — storage capacity data is not available for all areas.indicatiewettelijkvastgesteld) rather than abbreviations.Shape__Area uses double underscores (ArcGIS convention).Hand-maintained agent guide (ported from this collection's llms.txt in August 2026). Update it alongside collection.json.
| Perimeter in metres. |