Serbia Reservoir Transparency

RHMSS publishes daily river gauge data (water level, discharge, temperature) for 54 reporting stations on major rivers, updated daily at 10:00 local time. However, reservoir storage volumes are not publicly available through any national portal. EPS (Elektroprivreda Srbije), operator of the dominant Đerdap I/II HPP complex (~2,400 Mm³, over one-third of total national capacity), does not publish reservoir levels or storage volumes on its website. Srbijavode (the national water management enterprise) has a Web GIS portal but no accessible real-time reservoir storage dashboard. No national portal equivalent to Spain's MITECO or Portugal's SNIRH exists for reservoir fill levels. The only storage-adjacent data in the public domain are PDF hydrological yearbooks (surface waters, 1991–2024), which document river regime at stations near dams but do not report volumetric storage directly.

The RHMSS website offers RSS and ATOM feeds for current river gauge readings and PDF hydrological yearbooks (1991–2024) for historical data — both without registration. DanubeHIS (danubehis.org, launched December 2023) lists Serbia's RHMSS as a data provider and offers a Download API plus WaterML 2.0/XLS/CSV export, but requires free self-registration for downloads and covers only river gauge parameters (discharge, water level, precipitation, temperature), not reservoir storage volumes. No national REST API exists for reservoir data. The data.gov.rs open data portal (3,424 datasets) contains no identifiable hydrological or reservoir dataset from RHMSS. All data that does exist requires either PDF parsing or HTML table scraping for programmatic access.

Methodology v1.3.0 (capacity-weighted). Serbia's qualifying national reservoir capacity is approximately 3,500 hm³ across ~26–28 reservoirs above the 10 hm³ threshold (national subtotal; the bi-national Đerdap I/Iron Gate I on the Danube adds another ~2,400 hm³ that is shared with Romania). Đerdap I is the dominant single facility but EPS publishes no reservoir levels or storage for it; Srbijavode operates a Web GIS without an accessible reservoir storage dashboard; the RHMSS station network covers river gauges near dam sites rather than reservoir fill. Covered capacity through public Serbian sources is 0 hm³. Coverage = round(100 × 0 / 3,500) = 0.

RHMSS publishes downloadable PDF hydrological yearbooks for surface waters covering 1991–2024 — 34 years of annual data freely accessible. The 2025 edition is noted as 'under processing'. These yearbooks document river regime (water levels and discharges at hydrological stations) and are the longest continuous public hydrology record in Serbia, predated by data from 1923. However, they are in Serbian, in PDF format, and do not directly report reservoir storage volumes. DanubeHIS provides near-real-time data but its validated long-term time series are still being added. No machine-readable historical reservoir storage volume series is available from any public source.

RHMSS updates river gauge readings daily at 10:00 local time, and DanubeHIS receives near-real-time data from Serbia's RHMSS with readings timestamped roughly every 1–2 hours. However, this update cadence applies exclusively to river discharge and water level at gauge stations — not reservoir storage volumes. No operational reservoir fill-level portal exists that would make update frequency meaningful for the primary RTI purpose. The hydrological yearbooks (PDFs) are published annually, typically mid-year for the prior calendar year. Srbijavode publishes irregular bulletins on watercourse conditions during flood events.

RHMSS publishes general descriptions of its hydrological monitoring activities in English on its website, noting that its network monitors surface water regime via systematic observation and measurement. The department for hydrological analysis has a published scope document (in Serbian PDF). Historical hydrometric measurements in Serbia date to 1923. However, no publicly accessible technical document describes the specific measurement standards, calibration procedures, or volumetric calculation methods used for reservoir storage. As an EU candidate state progressing on Chapter 27 (Environment), Serbia is working toward Water Framework Directive alignment but the River Basin Management Plan for 2021–2027 had not yet been adopted as of the research date. ICPDR data policy documentation is available for the Danube basin framework.

RHMSS (hidmet.gov.rs) maintains a full English-language version of its website at /eng/ paths, covering hydrological data pages, station information, and service descriptions — a meaningful accessibility advantage over many Balkan peers. The daily water status table and station data are available in English. DanubeHIS is entirely in English and includes Serbian data. However, hydrological yearbooks (PDFs, 1991–2024) are in Serbian only. Srbijavode's website is in Serbian only. EPS's website has an English section but no data portal. The open data portal (data.gov.rs) is primarily in Serbian. Overall, the best-quality river data (RHMSS + DanubeHIS) is accessible in English, but no reservoir storage portal exists in any language.