IMPROVEMENT OF STORM-WATER RESERVOIRS FOR REDUCTION OF NON-POINT POLLUTION FROM URBAN AREA

Abstract

As a new measure for reduction of non-point pollution, we apply storm-water reservoirs in which basket mats are wholly and partially installed to improve flow patterns and increase residence time of particulate matter of non-point sources. To clarify the reduction effect of non-point sources using the improved storm-water reservoirs, we conducted field measurements on the bottom sediments in reservoirs located within the watershed of Lake Inba-numa. The measured results reveal that the improvement of the storm-water reservoirs may increase appreciably the trap effect of non-point pollution especially in the basket mats located near the inlet. These facts indicate that the partial improvements neat the inlets may be effective for the reduction of non-point sources in the whole watershed of Lake Inba-numa.