Pre-impoundment study of biotic communities of Kistobazar Nala in Purulia, West Bengal

Abstract

The Purulia Pumped Storage Project on Kistobazar Nala in West Bengal is proposed to improve the peaking power scenario of the state. The project in-volves construction of two reservoirs which would result in stream impoundment. Pre-impoundment studies were carried out on the physico-chemical characte ristics and the biotic communities at two sites (S1 and S2) lo cated downstream of the proposed upper and lower reservoirs, respectively. Except wa-ter -current velocity, no significant differences were observed between the two sites in their physico-chemical characteristics. Epilithic diatoms and macrozoobenthos, representing biotic communities, also did not exhibit variations in their diversity indi-ces at both the sampling sites. However, biotic com-munities differed significantly in their densities at sampling sites S1 and S2, with the latter represented by higher densities. These studies indicated that power development authorities should maintain op-timal water discharge during lean/dry periods down-stream of the proposed reservoirs, so as to maintain suitable ecological con ditions of the Nala similar or near -similar to that observed during the present study. Also stringent measures need to be adopted to check eutrophication of the reservoirs. These meas- ures would ensure development of a power pro ject in the area without adversely affecting the aquatic bio - d iversity of Kistobazar Nala. W