Low Impact Design on a Catchment Wide Basis - Is it Better than Site by Site?

This paper outlines the advantages and disadvantages of low impact design approach to management of stormwater quality and quantity in two catchments currently being studied within Manukau City. The soils in these catchments like other parts of Auckland are of low permeability and therefore present a high degree of constraints to implementation of on-site treatment of stormwater. The paper also discusses the issues relating to ownership, management and maintenance responsibilities of on-site and publicly owned stormwater assets.

The approach taken by Manukau City Council in both retrofitting and developing greenfield catchments with low impact design stormwater systems is also discussed in this paper.