Abstract
This article aims to present how to develop a comprehensive water quality index. Proposed indexing method consists of water quality parameters, weighting, value functions and aggregation process. Choice of parameters are based on a Delphi questionair tecnique. Result index WQI is applied to the Matsushima Bay in order to assess annual trend of water quality and to compare it's value with COD. It is concluded that a Delphi tecnique is useful to summarize the knowledge and experience of experts in water quality manegement and a developed water quality index WQI is an appropriate tool for evaluating overall water quality.
