Czechia Reservoir Transparency

For the COVERED subset (~38 strategic reservoirs across the five Povodí basin enterprises), data publication is sub-daily: each portal shows current water level AND storage volume in million m³, updated hourly. This places the typical covered reservoir well above the 'daily for >50%' band (80-99) and at the top of operational publication granularity. Per-reservoir pages include outflow rates, inflow estimates and percentage fill.

For the COVERED subset the dominant access mechanism is scrapable HTML/JavaScript web applications with no official documented REST API. An unofficial community PHP wrapper exists for Povodí Moravy (DanielKrasny/pmoAPI on GitHub) and ČHMÚ's opendata.chmi.cz serves JSON files but for river discharge stations, not reservoir volumes. All five portals provide English interfaces, well-structured HTML tables, and basic data exports (CSV) at the portal level, lifting this above pure scraping but keeping it below documented API tier.

Conservative estimate — denominator includes the long tail of ~53 mid-sized hydropower, drinking-water and industrial reservoirs >10 hm³ NOT in the public Povodí portals (Povodí enterprises focus on strategic reservoirs; the count-based national inventory of large reservoirs is ~91, of which only ~38 are in the public live publication), private industrial cooling pondages, and minor reservoirs at hydropower facilities not covered by the public dashboards. Methodology v1.3.0 (capacity-weighted). Covered capacity through the five Povodí basin enterprises is approximately 3,500 hm³. A realistic national denominator including the smaller hydropower/industrial reservoirs and private impoundments reaches approximately 4,100 hm³. Score = round(100 × 3,500 / 4,100) = 85. The largest reservoirs (Orlík, Lipno, the full Vltava cascade, Nechranice, Vranov, Nové Mlýny) are all covered; the conservative discount reflects the long tail of small-to-mid reservoirs systematically excluded from public Povodí portals.

Median historical depth across the ~38 covered reservoirs is approximately 5-10 years online. Povodí portals display graphs of recent trends (weekly, monthly views) and link to monthly 'bilanční data' (balance data) within their web interfaces. HEIS VÚV (Water Research Institute) holds static technical metadata. Underlying physical records at the Povodí companies extend far longer (50+ years for major reservoirs like Orlík, commissioned 1961), but publicly downloadable time-series of reservoir storage volumes are limited to the recent-years window shown in the portals. Median sits in the 5-10 year band.

All five Povodí portals update storage data hourly for the COVERED subset, exceeding the 'real-time or sub-daily (<24h) for >50% of covered' threshold. Povodí Moravy's VD Vranov shows measurement timestamps updated every hour; Povodí Labe specifies 'Data for past 24 hrs.' This is best-in-class update frequency for operational reservoir monitoring, placing Czechia alongside South Korea and Japan.

Individual reservoir pages show total design capacity, current volume in million m³, and percentage full, which implies publication of capacity parameters for the covered subset. The Povodí Ohře portal has a dedicated 'Capacities in reservoirs' page. HEIS VÚV publishes basic technical data for significant reservoirs including elevation-volume curves. The Czech Water Management Report is published annually by the Ministry of Agriculture. Detailed bathymetric methodology, uncertainty estimates and data collection procedures are not prominently published in English.

All five Povodí portals offer English-language interfaces. ČHMÚ's main portal (chmi.cz) and its flood service (hydro.chmi.cz) are available in English. HEIS VÚV has partial English content. The primary reservoir data portals (pvl.cz, pla.cz, poh.cz, pmo.cz, pod.cz) all provide navigable English versions showing reservoir names, water level, outflow and storage volume — a strong outcome among Central European peers.