COMPARATIVE STUDY ON THE WATER QUALITY OF KANIGIRI AND NELLORE RESERVOIRS OF ANDHRA PRADESH

To fill the gap at least to some extent that, very little information is available on hydrology of reservoirs of Andhra Pradesh so as to ensure sustainable management and optimum exploitation of these reservoirs, the present study was taken up. Analyzing the water for physico-chemical parameters is of prime importance to assess its quality for its best usage and also to know the pollution load, as these characteristics immensely influence the distribution and richness of biota, thereby gives a proper indication of the status, productivity and sustainability of a water body for different purposes. Hence, surface water samples were collected (December, 2015 to July, 2016.) from the chosen sampling stations of Kanigiri and Nellore reservoirs of SPSR Nellore district, Andhra Pradesh at fortnightly intervals and analyzed as per APHA standard methods to provide base line information on the physico-chemical characteristics of these reservoirs. The results obtained were found to be within the prescribed limits, except BOD as per BIS (2004) and total hardness, when compared with the standards (WHO, 1984; WHO, 2004; BIS, 1991; BIS 2012).  Total hardness values were much higher than the permissible limit as prescribed by WHO(1984) but well within the permissible limits as prescribed by BIS (1991) standards. The observed values were tested from fisheries  point of view also with the standards proposed  by renowned scientists of the field and found  to be well within the desired limits.

Though the values obtained were within the prescribed standard values, it was found that turbidity, TSS, TDS, TS, pH, BOD, NH₃, total alkalinity and total hardness values were found to be slightly higher in the water samples analyzed from Nellore reservoir, while transparency, DO, CO₂ levels seemed to be little higher in water samples collected from Kanigiri reservoir.(Table1)Mean chloride content and salinity values showed  negligible difference between the waters of both the reservoirs. Water quality of Kanigiri reservoir is comparatively good than the Nellore reservoir. Correlation among various parameters showed significant positive and negative trends. Water from both the reservoirs can be considered as 'alkaliphilous' based on pH values observed, 'soft' based on CO₂ values observed, 'nutrient rich' based on the total alkalinity values estimated, 'hard' with respect to observed total hardness values.