SUMMARY

Aquatic ecosystems perform valuable environmental functions like nutrient recycle, ground water recharge, stream flow maintenance, habitat for flora and fauna and provide recreation for people. Structural changes in these complex and dynamic ecosystems will have significant effect on its functioning. These structural changes take place due to unplanned developmental activities without holistic approach on watershed basis. These effects could be cumulative and its assessment is required for remedial measures. To assess these impacts due to river valley projects, the present study was undertaken in Sharavathi river basin. This is done through water, soil and sediment quality analyses by analytical methods. The water quality is impaired due to non-point source of pollution. This includes soil erosion and biological coliform at few sites. Soils under study are deficient in nutrients like nitrates, phosphate and sulphates but rich in organic matter. Since the character of sediment is highly dependent on the basin character, the soils of catchment having less amount of above-mentioned nutrients is consequently reflected in sediment also. The management options suggested are effective in soil erosion control based on soil type and appropriate catchment treatment.