Lake Loktak, Manipur

The site

The Lake Loktak complex (comprising the lakes of Loktak, Pumlen, Ikop, Kharung, Khoidum and others) forms an extensive floodplain system linked with the Manipur River. These floodplain wetlands produce fish and vegetables, moderate floods, support rich biodiversity and are inextricably linked to the Manipuri culture. They extend to 469 km2, with Loktak being the largest wetland of the basin, accounting for over 60% of the wetland regimes.

A characteristic feature of the wetland ecosystem is the presence of masses of floating vegetation locally called ‘phumdi’. A single 40 km2 chunk of phumdi in the southern part of the lake forms the Keibul Lamjao National Park, which is a habitat of the globally rare and endangered ungulate species, Rucervus eldii. In 1990, considering its rich biodiversity and socioeconomic importance, Loktak was designated by the Government of India as a Wetland of International Importance under the Ramsar Convention.

The issues

The diverse range of ecosystem services derived from the Lake Loktak is under stress owing to lopsided developmental planning within the basin. Water resources development projects for flood mitigation, agriculture and hydropower generation have led to modification of hydrological regimes,  seriously affecting the processes, functions and attributes of the wetlands. In particular, the construction of Ithai barrage downstream of Loktak in 1984 led to regulation of lake levels for hydropower generation. 

Rapid growth of population in the adjoining hills has led to expansion of the area under shifting cultivation, which has increased lake siltation and led to the loss of flood attenuation capacity. High levels of urbanization with inadequate sewerage have led to dumping of untreated sewage into the lake, leading to a decline in water quality. The declining resource base with increasing population pressure has forced the spread of harmful fishing practices. However, at the core of lake degradation is a lack of integration of ecosystem services into developmental planning processes.

Environmental services and the people involved

Environmental services

Water

People who provide the services

Loktak Development Authority

People who benefit from the services

Park management; state departments of wildlife, fisheries, public health; National Hydropower Corporation

People who act as intermediaries between the providers and the beneficiaries

Government of Manipur with technical support from Wetlands International

Loktak and associated lakes form the basis of food and water security for the state of Manipur as well as the entire northeastern region of the country. Lake Loktak is the largest fishery resource in Manipur, accounting for over half of its fish producing area. More than one-third of the lakeshore population derive their livelihoods from fisheries, with annual production ranging 1200–1600 metric tonnes during 1999–2003.

The lake also has over 132 plant species associated with the phumdithat are used by the people as food, fodder, fuel, thatch, fencing material, medicines, raw material for handicrafts, and for religious and cultural purposes.

Phumdi play an important role in maintenance of overall water quality through filtering of mineral nutrients. An estimated 478.60 tonne of nitrogen, 39.60 tonne of phosphorous and 157.20 tonne of potassium are annually accumulated within the phumdi of the northern zone. This huge amount of pollutants are brought in by the rivers, particularly the Nambul and Nambol and, if not absorbed by the phumdi, would have been available in the water thereby leading to further degradation making the lake unfit for fisheries and other aquatic life.  They are a source of a range of ecosystem services including providing fish, vegetables and water; moderating floods; improving water quality; and are inextricably linked with cultural and social life.

Lake Loktak is of immense cultural importance to the communities living in and around it. It is commonly referred to in local folklore as ‘Loktak Ima’ meaning ‘mother goddess’. The lake has been an important centre for cultural events, including Loktak Day, on which boat races are organized on the lake, which is the only venue for water sports in Manipur. 

The regulation of Lake Loktak through the Ithai barrage has led to the wetland becoming the source of another ecosystem service, that of providing water for generation of 105 MW of hydropower by the National Hydropower Corporation Ltd.

The rewards

Conservation and management of Lake Loktak mandates a strategic shift in water management, balancing human needs with the multiple values of the lake, through adopting a stakeholder-driven process.  Under the ambit of the RUPES project, Wetlands International South Asia and Loktak Development Authority, the government agency for lake management,  developed a water allocation policy that takes into account the various ecosystem requirements as well as human needs. 

A range of water management objectives were identified by the stakeholders: maintenance of the national park’s habitats, waterbird habitats, flushing of sediments, management of phumdis, and capture fisheries. These ecological concerns needed to be addressed through better management. At the same time, availability of water for hydropower generation, reduction in flooding in peripheral areas and supporting culture fisheries were human demands that could not be ignored. The ecological needs were aligned to the natural regime of water that existed prior to construction of Ithai barrage.  Under the current scenario, it was apparently impossible to meet all the management objectives. In particular, there were trade-offs between water allocation for hydropower generation and maintenance of the national park’s habitat in the lean seasons.

Based on the assessment of water regimes and needs of stakeholders, three water allocation scenarios—‘business as usual’, ‘mimicking natural regimes’ and ‘addressing multiple objectives’—were developed and assessed. The multiple objective scenario, which allows for maintenance of the national park’s habitats, flood moderation, fisheries and sustainability of ecosystem processes, along with hydropower generation, was endorsed by the steering committee.  During drier seasons, this would mean lowering hydropower production in favour of maintaining lake biodiversity and ecosystem processes. Building on the revision of water allocation policy, a rewards for environmental services’ scheme has been designed that will allow reinvestment of benefits from hydropower into lake conservation.

Follow-up

The steering committee recommended implementation of the revised water allocation policy. Based on the outcomes, an integrated wetland inventory and assessment initiative has been launched that will enable integration of ecosystem services with management planning, in particular, identifying conservation–development trade-offs. Under the ambit of the forthcoming five-year plan, the management of the associated wetlands of Loktak is also being integrated into river basin management, which, amongst other outcomes, is also expected to contribute to enhanced water availability within the system as well as improve hydrological connectivity. Payments for ecosystem services are being integrated into the institutional design as a means of sustaining financing for wetland management.

Site partners

  • Loktak Development Authority 

Loktak Development Authority is the nodal agency of the Government of Manipur for conservation and sustainable management of Lake Loktak. It functions under the aegis of the Department of Forests and Environment, Government of Manipur.

  • Wetlands International South Asia

Wetlands International South Asia is part of the global organization dedicated to conservation and wise use of wetlands, providing scientific and technical support to national governments, wetland authorities, non-governmental agencies and the private sector for wetland management planning and implementation of restoration programs.  

Contact for more information  

Dr Ritesh Kumar, ritesh.kumar@wi-sa.org