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Risks for every Czech address: floods, undermined land, radon, protected areas

One row per address point, 3,022,397 in all: flood zone Q5 to Q500, undermined land, radon index, landslides, protected areas, contaminated sites, water source protection zones and air quality. Plus a summary by municipality and 14 layers with geometry.

Free sample

One-time payment, final price for a personal licence, switch to business at checkout · data as of 10 November 2026

An island with a village by a swollen stream: a flooded meadow with willows, a sandbag barrier, a water gauge and a map pin at the house nearest the waterAn island with a village by a swollen stream: a flooded meadow with willows, a sandbag barrier, a water gauge and a map pin at the house nearest the water

How much work it saves

Downloading and unifying 14 layers from five authorities in four formats and three coordinate systems, repairing invalid geometries, simplifying 98 million flood-zone vertices down to 13.8 million and spatially joining 3.02 million addresses with every layer. Verified on well-known addresses (Karlín, Troja and Troubky in the Q100 zone, the undermined Ostrava area) and against PostGIS: differences at 116 addresses, all within 2 m of a zone boundary.

Measured on our own build

Lines of code and tests
1,626
AI agent tokens
40m
AI agent run time
61 mins

Tokens and time cover the first working version of the code, written with Claude Opus 5.5. Not counted: researching sources and licences, quality checks and later fixes.

  • Free sample: all tables cut down to the Kutná Hora area, in CSV and Parquet. Download the sample
Data as of
10 November 2026
Rows
4.4m
Tables
17
Formats
PostgreSQL, Parquet, CSV, JSON, GeoPackage
Source licence
CC BY 4.0 (VÚV TGM, ČGS, AOPK ČR, ČHMÚ, ČÚZK), MŽP

What’s inside

For every address point in RÚIAN, the Czech register of addresses, buildings, parcels and territorial units (3.02 million): flood zones Q5–Q500 (named after the flood return period in years) and the active zone, undermined land, distance to a mine working, radon index, slope instabilities, protected areas (small-scale reserves MZCHÚ, national parks NP, protected landscape areas CHKO and their zones, Natura sites EVL, bird areas), distance to a contaminated site, water source protection zones and air quality; a summary by municipality and all layers with geometry (GeoPackage, GeoParquet, PostGIS).

TableRows
adresy_rizikaRisk profile of a RÚIAN address point: flood zones, undermined land, mine workings, radon, slope instabilities, protected areas, contaminated sites, water source protection zones (OPVZ), air quality3,022,397
obce_rizikaSummary of the risk profile by municipality: counts and shares of address points in the zones6,258
ovzdusi_petiletiAir quality from ČHMÚ, the Czech Hydrometeorological Institute: five-year average concentrations on a 1 × 1 km grid, every five-year period from 2007–2011 onwards1,201,825
zaplavova_uzemiFlood zones Q5, Q20, Q100, Q500 and active zones (VÚV TGM, the Czech water research institute; ISVS-VODA)3,995
zaplavova_uzemi_usekyWatercourse sections with a flood zone designated by decision of the water authorities (VÚV TGM)2,327
poddolovana_uzemiUndermined areas (ČGS, the Czech Geological Survey), converted from WGS84 to S-JTSK, the Czech national coordinate system5,674
dulni_dilaMine workings (ČGS)30,889
radonovy_indexRadon index map of the bedrock, 1:50,000 (ČGS)35,714
svahove_nestabilitySlope instabilities: landslides, flows, rockfalls (the ČGS register of slope instabilities, INSPIRE)27,278
mzchuSmall-scale specially protected areas (AOPK ČR, the Czech nature conservation agency)2,688
Show all 17 tables
TableRows
vzchuLarge-scale specially protected areas: national parks, CHKO and national park buffer zones (AOPK ČR)33
vzchu_zonyZoning of national parks and CHKO (AOPK ČR)123
evlNatura 2000 Sites of Community Importance (AOPK ČR)1,111
ptaci_oblastiNatura 2000 bird areas (AOPK ČR)42
kontaminovana_mistaContaminated and potentially contaminated sites from the SEKM register (MŽP, the Czech ministry of the environment)10,184
opvzProtection zones of water sources and drinking water reservoirs (VÚV TGM, ISVS-VODA)16,289
ovzdusi_bunkyČHMÚ air quality grid, 1 × 1 km, with the 2021–2025 averages (geometry of the latest five-year period; for earlier periods see ovzdusi_petileti)80,096

The data is indicative and does not replace an official statement. Flood zones are designated on only some watercourses, so an address outside them is not free of risk. The 1:50,000 radon map cannot be used for an individual building.

Downloads

Every format contains the same data. Download only the one you need; verify its integrity with the SHA256SUMS file.

FormatFilesSize
PostgreSQLschema.sql with types, keys, indexes and comments, and import.sh, which loads the data from CSV453 kB
ParquetOne file per table (zstd). DuckDB, Polars and pandas read it without an import.17416 MB
CSVUTF-8, comma-separated, with a header; large tables as .csv.gz17404 MB
JSONAn array of objects; large tables as JSON Lines (.jsonl.gz)17186 MB
GeoPackageThe current state of all layers in one file, history per table. QGIS, GDAL, SQLite.1245 MB

Code example

More examples for SQL, DuckDB, Python and Node.js are in the README.md inside the bundle.

Risk profile of one addressPostgreSQL
-- je adresa v záplavovém území?
SELECT zu_q100, zu_nejmensi_q, zu_tok, zu_q100_vzdalenost_m, poddolovani, radon_kategorie, vzchu_nazev
FROM rizika_adres.adresy_rizika WHERE adresni_misto_kod = 27613372;
Municipalities with the largest share of addresses in Q100PostgreSQL
-- obce s největším podílem adres v Q100 (aspoň 500 adres)
SELECT obec, adres_se_souradnicemi, adres_q100, podil_q100_pct
FROM rizika_adres.obce_rizika WHERE adres_se_souradnicemi >= 500
ORDER BY podil_q100_pct DESC LIMIT 20;
Addresses with risks, no importDuckDB
-- adresy ze sady ruian + rizika
SELECT a.adresa, r.zu_q100, r.poddolovani, r.ovzdusi_pm25
FROM 'adresy-2026-09.parquet' a JOIN 'parquet/adresy_rizika.parquet' r USING (adresni_misto_kod)
WHERE a.obec = 'Ostrava' AND r.poddolovani LIMIT 10;

Source and licence

Sources
Processed by
czechdatasets.com. The data is modified and is not an official output of the authority; the required attribution is in LICENCE.txt.

Joins with

Datasets share RÚIAN codes and IČO, so one JOIN connects them.

RÚIAN with history

Complete RÚIAN data: Czech parcels, buildings, addresses, streets and territorial units for the whole country. The current state and every version since August 2015, month by month.

1,990 CZKDataset details

Address geocoder and autocomplete

Autocomplete, geocoder and reverse geocoder for all 3,022,397 Czech addresses with postal codes. Runs in your PostgreSQL, Meilisearch or Typesense: no paid API, no data sent to a third party.

690 CZKDataset details

Municipalities in numbers 2000–2025

786 Czech Statistical Office (ČSÚ) indicators for every municipality since 2000: population, schools, doctors, businesses, unemployment, budgets and censuses. One table with official municipality codes, plus 36 key figures for each municipality.

290 CZKDataset details

More datasets

Address risks for 790 CZK.

One-time payment, download right after paying, no account and no subscription. Updates to the dataset are included in the price. All 15 paid datasets together cost 2,490 CZK, 3,510 CZK less than buying them one by one.