Some water tanks do not need development or building approval if they comply with rules set out in regulations.

Exemptions from development approval

You don’t need development approval if a water tank complies with relevant provisions (Schedule 1, Part 1.3, Division 1.3.2, Section 1.55) of the Planning and Development Regulation 2008, Schedule 1.


A water tank doesn’t need development approval if:

  • capacity is not more than 20kL
  • it is not higher than 3m above natural ground level
  • if any part of the tank is located between a front boundary and a building line for the block—the whole tank is buried under the natural ground level
  • Water tanks are classified as class 10 structures. Additional criteria apply if two exempt class 10 structures would be built within 1.5 metres of a side or rear block boundary. For more about a second building in clearance area see ACTPLA’s webpage or view the criteria at (Schedule 1, Part 1.3, Division 1.3.2, section 1.41) of the regulation.

If you are seeking to build on a rural block different exemption rules apply. (See Schedule 1, Part 1.3, Division 1.3.5, Section 1.85 of the regulation).

If the site is on national land you should contact the National Capital Authority for development approval.

If you are still unsure whether your development is exempt you should check the regulation or call ACTPLA on phone: (02) 6207 1923.

A building certifier can ensure plans and work are completed in accordance with the law.

Exemptions from building approval

You don’t need building approval if the proposed water tank complies with relevant provisions of the Building (General) Regulation 2008, Schedule 1.
Note: water tanks are grouped as class 10b buildings in the building regulation.


The water tank is exempt provided that:

  • capacity is not more than 20kL
  • it is not more than 2.4m above ground

General rules for exempt building work

The proposed structure doesn’t adversely affect:

  • the structural integrity of any part of the building
  • a fire-rated wall, ceiling or floor
  • a fire escape, emergency lift, stairway, exit or exit passage
  • the natural light, the ventilation or fire protection system
  • the proposed structure doesn’t affect the building in a way that reduces its compliance with the Building Code to below minimum requirements
  • erection of the structure doesn’t involve handling asbestos or disturbing friable asbestos.

For more information on exempt development call ACTPLA on phone: (02) 6207 1923.

Related documents:

Rainwater tanks - guidelines for residential properties in Canberra