The 105 MW Loktak hydroelectric power project was commissioned in 1983 with a view to promoting the rapid industrial, commercial and agricultural development of the state. However, the project proponents did not take into account the effects on the lake ecosystem, the people and wildlife whose lives are connected with the lake in their cost-benefit analysis. Within a few years of the project's commissioning, it became evident that the lake was undergoing drastic changes.
Picture: Salam Rajesh
i) Water level was maintained at a constant level of 768.9 m. throughout the year to provide adequate water supply for the hydro project. Due to this, a huge agricultural area on the periphery of the lake was adversely affected. According to a complaint lodged by the Loktak Lake Affected Areas' Peoples' Action Committee, an estimated 80,000 ha. of arable land was destroyed by water inundation and frequent flash floods through the year after the project was commissioned. This is in addition to the huge tract of settlement lands affected by the project both around the lake and downstream of the Ithai barrage.
ii) The Ithai barrage of the hydro project, constructed at the confluence of the Manipur river, the Khuga river and the Ungamel channel near the Ithai village south of the Loktak lake, obstructed traditional river passage, leading to several consequences. The loose phumdi (floating vegetation) that used to flow out from the lake through the Khordak channel to the Manipur river and then down to the sea through the Chindwin-Irrawaddy river system in western Burma, was blocked. This led to congestion and stagnation of the vegetation mass in the lake and a reduction in the clear water surface. It also encouraged the process of eutrophication in the lake. The massive phumdi pile-up in the lake also encouraged locals to construct more floating hutments for fishing. Furthermore, the Ithai barrage blocked the traditional migration of fish species coming upstream from the Chindwin-Irrawaddy river system to spawn in Loktak and the adjoining wetlands. This has been reflected in the falling fish catch.
iii) The high water-level has caused many species of migratory waterbirds to seek feeding grounds elsewhere. Species such as the Sarus Crane, Hooded Crane, Greylag Goose, Bar-headed Goose, Large Whistling Teal and Ruddy Shelduck have stopped visiting the lake.
iv) The Ithai barrage has seriously affected the viability of the Keibul Lamjao National Park, the home of the famed sangai – the Manipur brow-antlered deer. The park experiences flash floods and periodic, sudden increases in water level, especially in the monsoon, when the waters of the Khuga river, after hitting the Ithai barrage, gush in through the Ungamel channel to the southern edge of the park. This damages the vegetation mass, which provides shelter to wildlife. The havoc and dislocation this causes among the wildlife is then exploited by poachers.