Sea level rise and coastal

erosion adaptation:

Coastal Development Set

Back lines

By

Andrew A. Mather

eThekwini Municipality, P.O. Box 680, Durban, 4051, South Africa. mathera@durban.gov.za

Presentation outline

• Definition of a coastal set back line

• Difference between “physical

process” and “limited development”

coastal set back lines

• Need for set back lines

• Progress in South Africa

• Challenges

Definition

A development set-back line is defined as the line landward of which fixed structures may be built in order to be reasonably safe against the physical impact of coastal processes

Coastal set back line (s)

PHYSICAL

PROCESSES LINE

OR

HAZARD LINE

A line which

predicts the future

limit of the

physical

processes

A line which buffers

the physical

processes line by

incorporating

environment,

heritage and social

factors

LIMITED

DEVELOPEMENT

LINE

Coastal set back line (s)

PHYSICAL

PROCESSES LINE

OR

HAZARD LINE

A line which

predicts the future

limit of the

physical

processes

A line which buffers

the physical

processes line by

incorporating

environment,

heritage and social

factors

LIMITED

DEVELOPEMENT

LINE

SEASONAL

BEACH

CHANGE

SEASONAL

BEACH

CHANGE

SEA LEVEL RISE

PHYSICAL

PROCESSES

LINE

SLR

Amanzimtoti in Jan 2007

Amanzimtoti in July 2007

Av. 100 m

SEASONAL

BEACH

CHANGE

SEASONAL

BEACH

CHANGE

SEA LEVEL RISE

SLR

Need for coastal setback lines

• Legal requirement of the Integrated

Coastal Management Act

Need to complete ~3000 kms in South Africa

by Dec 2013.

• Rapid development of the coastal zone

has increased from 28% in 1994 to over

50% in 2006 (Cilliers 2006) transforming

vast areas of coastline.

Need for coastal setback lines

• To protect the public from themselves

• Climate change

Sea level rise (Mather 2007, Mather et al. 2009)

changes in ocean storminess and

changes in predominate wave direction (Corbella

and Stretch 2011- Session D earlier today

Mather, A.A., Garland, G.G. and Stretch, D.D. 2007. Linear and Nonlinear sea level changes at

Durban, South Africa, South African Journal of Science, November/December 2007.

Mather, A.A., Stretch, D.D. and Garland, G.G. 2009. Southern African sea level: corrections,

influences and trends. African Journal of Marine Science, 31(2), 145-156.

PROGRESS IN SOUTH AFRICA

• Richards Bay 11 kms completed

• Durban 100 kms completed

• KwaZulu-Natal 609 kms in progress

• Port Elizabeth 100 kms in progress

• Overberg 300 kms in progress

Still to complete ~2000kms in 30 months

Challenges

• Provinces are tasked with rolling out

Coastal set back lines

• Each Province is adopting a slightly

different approach

• At a National level there is uncertainty

about what methodology should be

adopted

Challenges (cont.)

• Rollout is very much dependant on funding

availability

• Some provinces are funding this work

while others do not have budget allocated

to implement

• Shortage of firms in South Africa (3 or 4)

capable of implementing coastal set back

lines

Challenges (cont.)

• Only two coastal municipalities (Cape

Town and Durban) have the capacity to

undertake this work in house

• Virtually all other Local Government

officials have little experience of this type

of work resulting in a lack of buy in to the

process/ little financial budget allocation.

Thank you.

See you at COP 17.