ROLE OF BUFFER STRIPS IN MANAGEMENT OF WATERWAY POLLUTION - A REVIEW

A buffer strip can perform a multitude of functions, and these include channel stability, a filter for sediment and nutrients, water purific ation (e.g., bacteria and pathogens), a nondisturbance area, and the p rovision of terrestrial and stream habitat. These functions are review ed with specific application to Australian conditions, and methods for modeling their performance are outlined. The primary focus is on the use of buffer strips to minimize waterway pollution from diffuse sourc es since their use is often justified on this basis. Particular attent ion is given to the conditions under which a buffer strip will act as an effective filter and the conditions under which it will fail. Buffe r strips are most effective when the flow is shallow (nonsubmerged), s low, and enters the buffer strip uniformly along its length. Their sed iment trapping performance decreases as the sediment particle size dec reases. Nutrients are often preferentially attached to fine sediment. As a result, buffer strips are better filters of sediment than of nutr ients. Buffer strips should only be considered as a secondary conserva tion practice after controlling the generation of pollutants at their source and, to be effective, buffer strips should always be carefully designed, installed, and maintained.