Southern Africa is generally a semi-arid region. Overall, average runoff only constitutes 9% of the total rainfall with 91% of all precipitation evaporating again. This compares poorly with the world average runoff ratio to rainfall of 35%. Not even a relatively wet province such as KwaZulu-Natal, with a 16.5% runoff ratio comes close to the world average. To exacerbate the runoff problem, its spatial distribution is highly uneven, with high runoff rates along the eastern coast and very low runoff rates in the Western and Northern Cape.

The following datasets can be viewed:

Primary catchment runoff
Secondary catchment runoff
Tertiary catchment runoff
Quaternary catchment runoff

PRIMARY CATCHMENT RUNOFF:
Choose a province to view map or click on province in image

Eastern Cape
Free State
Gauteng
KwaZulu-Natal
Mpumalanga
Northern Cape
Northern Province
North West
Western Cape

SECONDARY CATCHMENT RUNOFF:
Choose a province to view map or click on province in image

Eastern Cape
Free State
Gauteng
KwaZulu-Natal
Mpumalanga
Northern Cape
Northern Province
North West
Western Cape

TERTIARY CATCHMENT RUNOFF:
Choose a province to view map or click on province in image

Eastern Cape
Free State
Gauteng
KwaZulu-Natal
Mpumalanga
Northern Cape
Northern Province
North West
Western Cape

QUATERNARY CATCHMENT RUNOFF:
Choose a province to view map or click on province in image

Eastern Cape
Free State
Gauteng
KwaZulu-Natal
Mpumalanga
Northern Cape
Northern Province
North West
Western Cape