The paper aims at discussing the methodology used to develop loss functions
for flood mitigation measures, using historic data of flood damage to infr
astructure. The main determinants of the extent of damage are the size of t
he flood and the length of the infrastructure within the boundaries of the
flood-line. In regression analysis, flood peak was used as the independent
variable in the Cobb-Douglas functions to depict the relationship between d
amage and flood peak. The Mfolozi flood-plain in Northern KwaZulu-Natal ser
ved as the study area. Loss functions for infrastructure, for ex ante estim
ation of damage to infrastructure, were developed for inclusion in a flood
damage simulation model (FLODSIM) developed by the Department of Agricultur
al Economics of the University of the Orange Free State in collaboration wi
th the Water Research Commission. Loss functions were determined for spillw
ays, levees, tramlines. public roads, drains and bridges.