AquaINFRA’s DDAS Progress

Integrating diverse environmental data is a core challenge that AquaINFRA’s Data Discovery and Access Service (DDAS) is tackling. At the AquaINFRA conference, the DDAS development team reported significant progress in connecting various water-related data sources across Europe and beyond. As the team noted at the recent AquaINFRA assembly in Oslo, integrating many different data APIs is “like trying to fit blocks of varying squareness through a round hole,” where some data sources fit easily, others require effort, and a few are so “square” that only a corner can go through. In practical terms, this means the team is dealing with a myriad of data service standards, from standard OGC web services to custom APIs, and finding ways to make them all accessible through one platform.

Despite the challenges, the DDAS has successfully linked to numerous major repositories. For example, it now taps into the official European open data portal (data.europa.eu) via a REST API, and into the European Digital Twin Ocean catalog via its spatiotemporal API. Likewise, connections have been made to specialized scientific data centers: the CUAHSI Water Data Center for hydrological observations and PANGAEA for earth and environmental science datasets. Each of these external services had different formats and quirks, with some complex time-series web services “too square” to integrate fully. Despite these challenges, the progress by late 2025 included incorporating all these sources so that a user can seamlessly search across them via AquaINFRA’s interface.

Beyond external catalogs, AquaINFRA’s own dataset collection has grown through DDAS. The team added metadata for important global hydrography datasets (the HydroSHEDS collection, including HydroBASINS, HydroLAKES, and HydroRIVERS) into AquaINFRA’s database. These datasets provide information on river networks and water bodies, and by integrating them, AquaINFRA ensures researchers can find and download these baseline data sets. Additionally, national data is being brought in. The Finnish Environment Institute (Syke) contributed data services, one for water clarity (Secchi depth) and another for in-situ water quality measurements, which DDAS now harvests through custom APIs. By incorporating such regional data streams, AquaINFRA’s portal becomes more valuable for local-scale studies while maintaining a pan-European scope.

Building DDAS isn’t just about plugging in data sources, but also about adding features for the user community, including the creation of an “AquaINFRA community” space and efforts to streamline user access through membership management. On the technical side, the team is in early stages of enabling direct API integration for user-developed tools, hinting at future possibilities where researchers could plug their applications into AquaINFRA’s data flow. They are also exploring connections with big European data infrastructures: for example, integrating the EUDAT B2SHARE service for sharing datasets, and investigating the Helmholtz Coastal Data Center API (although the latter was noted to be particularly “square,” meaning it may not be straightforward to include). Ongoing maintenance, such as fixing a broken link to the UK’s CEDA data API, is part of the development to-do list.

Why does this matter? For an environmental scientist or decision-maker, DDAS promises a one-stop search to discover water and climate data across many repositories with one query. Instead of separately searching national databases, European portals, or thematic archives, AquaINFRA’s DDAS will let users find all relevant data in one place, following FAIR principles (findable, accessible, interoperable, reusable). The work presented shows a concerted effort to bridge different systems into a unified discovery tool. By late 2025, the team had already expanded the service with new data sources and demonstrated the platform’s flexibility in adapting to various formats. The ultimate goal is an ecosystem where, for example, a query for “river discharge in the Baltic” or “Mediterranean chlorophyll data” retrieves results from multiple sources seamlessly.

The development status from the Oslo meeting indicates that AquaINFRA’s data integrators are steadily hammering those “square pegs” into the round hole of a common platform. With continued integrations and bug fixes planned, the DDAS is set to become a cornerstone for aquatic research, saving users time and improving the accessibility of critical hydrological and oceanographic information. The thanks given by the team to collaborators and the community underscores that this is a collaborative, cross-border effort. As AquaINFRA moves forward, its Data Discovery and Access Service stands to significantly lower barriers for scientists in accessing the rich array of water data needed for research and environmental management.