Assessment of Water Quality of Vishwamitri River to Explore Environmental Flow Requirements

Environmental flow is essential for restoring ecological health of a river. Reviewing water quality is integral determinant for exploring Environmental Flow Requirements (EFR) of any river. Vishwamitri is a seasonal river, affected by various Point Sources (PS) and Non-point Sources (NPS) of pollution. This study projects the assessment of various general physico-chemical parameters, heavy metals and biological parameters for water samples collected from various seven sampling stations along the Vishwamitri River. From the analysis it is observed that both BOD and COD values are found more whereas DO values are found less than the desirable limit in downstream water of Vishwamitri in all seasons. The colour of water is mostly observed changing from colourless to slight yellow at downstream stretch of the river in both the premonsoon and monsoon seasons. River near Kalaghoda Bridge in Vadodara City has represented odorous water quality in all seasons. At most of the sampling locations, total coliforms counts were exceeding the limits of standard of class „C‟ during pre-monsoon and monsoon seasons. In monsoon and post-monsoon seasons, most of the sampling stations represented considerably less counts of fecal coliforms. The values of iron and zinc were also observed higher than desirable limit at few sampling stations. Slight changes in the water quality of the river water were observed due to dilution and variation in flow conditions during the monsoon and post-monsoon period. Continuous monitoring of water quality of Vishwamitri and implementation of action plans to control pollution of river is an urgent need.