Kullu: What appeared baseless apprehension regarding execution of large hydro power projects in Himachal, is now proving true, at least part of it. Though environmental groups and people residing in areas where large projects are being executed have always been suspicious about their ill-effects, but now for the time it has been established through a scientific study that not all is well with these projects.
A GIS-based hydrological model case study of Hurla basin, that is part of the Parbati II project in Kullu district, carried out by INRM-Technology House Consortium, has shown that inter-basin transfer of water will severely alter the ecological and social stability of the area. As part of the project, discharge data and observations of flows at Manihar, Pancha and Hurla rivers were studied for years 2004, 2005 and 2006. From the data available, the following facts emerged:
• The lean flows of Manihar and Pancha are very small, almost 0.2 cumecs in case of Manihar.
• It is apparent that these three streams would have almost negligible contribution to the NHPC project for almost six months. The lean flow of 0.2 cumecs for Manihar for example (as against Parbati II design discharge of 200 cumecs) would hardly contribute to power generation and would instead invite the risk of importing cloud burst material into the main tunnel of the project from these flashy streams. The Pulia cloud burst conforms this.
• The Manihar and Pancha areas have adequate habitation, cultivated terraces, gharats which would all be adversely affected by this diversion.
• Hurla is relatively a wide valley with flora and fauna and habitation downstream and gets very little contribution from downstream streams, unlike its neighbor Parbati which has good recharge from downstream confluencing nallahs. Thus Hurla’s potential for improving agriculture and horticulture in its catchment area would be hampered.
• Due to increasing consumptive usage of water in the Hurla basin and decreasing lean flows due to climatic changes, the smaller streams confluencing downstream of the NHPC tapping point would lead to disruption in maintaining the eco-system of the area and stop avenues of horticulture/agricultural growth.
• Some of the perennial streams confluencing downstream of the NHPC tapping point are dried /near zero flow, which is a serious issue during the lean season and attributed to climatic change. As such, the project was conceived more than a decade ago, but the hydrology particularly that of small streams, has since changed. The smaller snow cover of these streams has in fact led to two lean seasons, one being in June as well (due to snow cover depletion), till the monsoon arrives in end June /July. The situation in post-Parbati scenario in case of a drought year like in 2002 would be even worst.
• It is ironical that while NHPC’s infrastructure development of the area deserves applause, it also opens up avenues for the locals to increase out horticulture and agro- related activities due to improved logistics; the same would be dampened due to the upstream diversion.
Keeping these facts in mind, it has been suggested that NHPC reconsider tapping of the Manihar and Pancha Nallahs for the Parbati II project and conserve the flora and fauna of Hurla valley.