Risks and legal situations

Flood zone (záplavové území)

In Czech: Záplavové území

A flood zone (záplavové území) is an officially defined area that may be flooded in a flood. It is set by the regional authority through a general measure, and statutory restrictions apply in its active zone, for example to building.

Also called: záplavové území, floodplain, flood risk area, aktivní zóna

What it means

A flood zone (záplavové území) is an officially defined area that may be covered by water during a flood. It is not a forecast that a particular house will flood, but a designation that authorities use when approving construction and that insurers may also rely on.

Within the flood zone, an active zone (aktivní zóna) is defined: the part through which the main flow of water runs during a flood. The difference matters to owners and buyers, because the statutory restrictions are tied specifically to the active zone.

How it works in the Czech Republic

Under § 66(1) of the Water Act (vodní zákon), the flood zone is set by the water authority, which is the regional authority (krajský úřad), through a general measure (opatření obecné povahy) proposed by the watercourse manager. Under § 66(2) it also defines the active zone.

The statutory restrictions under § 67 of the Water Act apply in the active zone. Check exactly what they restrict and which exceptions exist in the current text of the act or directly with the water authority, especially if you plan to build or extend.

Maps of designated flood zones are published by state institutions, and the regional authority or the municipality can also advise on a particular plot. It is worth comparing the information with the municipal zoning plan (územní plán).

Practical example

For example, a family is considering a house by a river for CZK 5 million (illustrative amount). The map shows the house is in a flood zone but outside the active zone. They ask the building office whether they could add a garage and an insurer on what terms it would cover the house. Only with these answers do they negotiate the price.

What to watch out for

  • Check whether the property lies in a flood zone and, in particular, in its active zone.
  • Ask the seller and the neighbours whether and when the area flooded and what damage the water caused.
  • Before buying, find out from an insurer on what terms flood cover is available.
  • If you plan to build or extend, discuss it first with the building office and the water authority.
  • Being outside a flood zone does not mean water cannot come, for example after a sudden downpour.

Frequently asked questions

Who designates a flood zone?

The water authority, which is the regional authority, through a general measure proposed by the watercourse manager (§ 66(1) of the Water Act).

Can I build in a flood zone?

It depends mainly on whether the plot is in the active zone, where statutory restrictions apply, and on the authorities' assessment. Always discuss your plan with the building office and the water authority first.

Can a house in a flood zone be insured?

Each insurer sets its own terms. Ask for a quote before you buy.

  • Zoning plan (územní plán)A zoning plan (územní plán) is a municipality's main planning document. It sets where building is allowed, what each area may be used for and which conditions apply to development, so it is worth checking before buying land or a house.
  • Building plot (stavební pozemek)A building plot (stavební pozemek) is, under the Czech Building Act, a plot, part of a plot or a group of plots defined and designated for building. Whether you may really build on it depends mainly on the municipal zoning plan.
  • Buildability of land (zastavitelnost)Buildability of land (zastavitelnost pozemku) describes whether and how much you can build on a plot. No single document decides it: it combines the zoning plan, land type, protection zones, flood zones, access and utilities.
  • Family house (rodinný dům)A family house (rodinný dům) is a building intended mainly for one or a few households, either detached or attached to neighbouring houses. It is usually sold together with the land, of which the building is legally a part.
  • Waterproofing (hydroizolace)Waterproofing (hydroizolace) is a layer or treatment that stops water and ground moisture getting into walls, floors, cellars and the roof. Where it is missing or worn out, you get damp, mould and crumbling plaster.

Sources

Laws and official pages this text is based on (in Czech).

This text is for information only and has not yet been checked by a legal or financial expert. It is not legal, tax or financial advice. Verify important details in the listed sources or with a professional.

Updated 25 October 2026

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