Dam safety within the South African context

What is the Dam Safety Office?

South Africa is one of the 30 driest countries in the world. As such, dams form a key component of South Africa’s water management and storage infrastructure. It is well known that water use within South Africa is regulated through the National Water Act of 1998, but what is less well known is that this Act also regulates the safety of dam infrastructure within the country, through the Dam Safety Office (DSO).

The DSO falls within the Department of Water Affairs and Sanitation, whose office is responsible for administrating the Dam Safety Regulations. This legislation applies to all dams with a safety risk, which are defined as being all dams with a storage capacity greater than 50 000 m³ and a wall height over 5 m.

Keys tasks performed by the Dam Safety Office include the following:

Classification and categorisation of dams in terms of the risks they pose,
Ensure regular dam safety evaluations are undertaken by dam owners at regular intervals for all dams that are categorised as posing a safety risk,
Issue construction permits for new dams being proposed, and
Issue permits to impound water once new dams have been constructed.

How are dams in South Africa Categorised?

Dams in South Africa are categorised from 1 to 3 based on two criteria:

The dam’s SIZE CLASS based on the maximum wall height, and
The dam’s HAZARD RATING, which considers the possible loss of life alongside the economic and environmental impacts, should the dam fail.

The image below depicts how a dam is categorised in relation to its size class and hazard rating.

What is an Approved Professional Person?

An Approved Professional Person (APP) is a professional whose experience has been vetted and confirmed appropriate by the DSO for the different dam safety categories identified. Furthermore, limits are placed on the APP within each of the safety categories in terms of the dam type, height and magnitude of the floods to be transmitted. APPs are required to be involved in the following tasks:

Safety evaluations of existing category 2 and 3 dams,
Construction of new category 2 and 3 dams,
Alterations and raising of existing category 2 and 3 dams, and
Decommissioning of existing category 2 and 3 dams.

What can MBB do for you?

With more than 40 years of experience in the development of small, medium and large dams in Southern Africa, MBB has the people and expertise to provide the following specialist services: