Power line protection zone

A power line protection zone is the space immediately around a power line or substation that, under Section 46 of the Czech Energy Act, secures reliable operation of the equipment and protects people's lives, health and property. It arises directly by law on the day the permit for the project becomes final or, where no permit is required, when the equipment is put into operation. It is not entered in the land register and ends when the structure is permanently removed. Zones for all networks are summarised under utility protection zone.

Widths by voltage

For overhead lines the zone is measured horizontally and perpendicular to the line from the outermost conductor on each side:

• above 1 kV up to 35 kV, typically 22 kV high voltage: 7 m for bare conductors, 2 m for conductors with basic insulation, 1 m for aerial cables,
• above 35 kV up to 110 kV: 12 m for bare conductors, 5 m with basic insulation, 2 m for 110 kV aerial cables,
• above 110 kV up to 220 kV: 15 m, above 220 kV up to 400 kV: 20 m, above 400 kV: 30 m,
• overhead low-voltage lines up to 1 kV have no protection zone.

Underground cables have 1 m on each side up to 110 kV and 3 m above 110 kV. For substations stepping down to low voltage it is 7 m from the footprint of a pole or tower substation, 2 m from a compact or brick substation and 1 m from a built-in one; outdoor substations and those above 52 kV in buildings have 20 m.

Lines built by the end of 1994

Protection zones set under earlier rules remain unchanged (Section 98(2) of the Energy Act). Under ČEZ Distribuce's conditions, equipment built by 31 December 1994 therefore has 10 m instead of 7 m for bare-conductor lines above 1 kV up to 35 kV (7 m in forest clearings even for these) and 15 m instead of 12 m for bare-conductor lines above 35 kV up to 110 kV. The year the line was built therefore matters.

What applies inside the zone

• Without the equipment owner's consent you may not build, place structures, store flammable or explosive substances or carry out earthworks.
• Activities that would endanger the equipment's operation or people's safety, or hinder access to the equipment, are prohibited.
• Under an overhead line, hop gardens may not be planted and vegetation must not grow above 3 m.
• Above an underground line, permanent vegetation may not be planted and machinery over 6 t may not cross the line without protection.
• The equipment owner gives consent to a building or activity in writing and with conditions (Section 46(8) to (11)).

Frequently asked questions

How do I find the zone width on a plot?

From the voltage and type of conductors stated in the distributor's statement on existing networks, and from the year the line was built. The zone is measured from the outermost conductor, not from the centre of the pole. The exact position of an underground cable is shown by marking it out before earthworks.

Is a protection zone the same as an easement?

No. A power line easement is entered in the land register and gives the distributor the right to keep the line on someone else's land. A protection zone arises by law even without any entry and restricts activities around the line, including on neighbouring plots the line does not cross.