印旛沼の水環境再生を目的とした市街地流域対策に関する総合的検討

摘要

For restoration of water environment in Lake Inba-numa, we studied the performance of rainwater-infiltration inlet and storm-water reservoir as measures in an urban catchment area of Lake Inba-numa. We have conducted field measurements for water cycle and pollutant load in urban areas with and without infiltration measures. Also the inflow and outflow loads of pollutants were measured in a storm-water reservoir. The results indicate that the surface runoff ratio and specific pollutant load in the urban area with infiltration measures were appreciably smaller than that without the measures. The inflow pollutant loads were significantly reduced in the storm-water reservoir. These facts indicate that these measures works well for reduction of non-point sources and restoration of spring water.