The Nagoya Waterworks and Sewerage Bureau has developed original supporting tools for the systematic and cost-effective management of problem solving. An environmental information map and prediction of pollutant reaching are used for rapid and appropriate proper countermeasures against water quality accidents in the source area. In disinfection byproduct control a method for estimating trihalomethane (THM) contents was effective for the complement of their observations. Surrogate indicators such as turbidity and conductivity that could be measured continuously also could complement water quality items measured monthly. A processing tool of voluminous data was practical for rapid judgment of water quality. Systematic monitoring was established for stricter turbidity control for measures against Cryptosporidium and keeping residual chlorine stable in the service area.