Kolleru Lake

Kolleru lies between the Krishna and Godavari deltas in Andhra Pradesh. The Ramsar Convention describes the lake as a natural, nutrient-rich freshwater system fed by seasonal rivers, drains and channels, and identifies it as a natural flood-balancing reservoir between the two deltas. Its water level responds to monsoon runoff and seasonal drying. The Key Biodiversity Areas factsheet describes extensive variation in the lake’s surface area with changing water levels; its figures refer to particular flood conditions rather than a fixed year-round shoreline. Consequently, area estimates depend on season and on which wetland boundary is being measured.

The lake and its associated marshes provide habitat for resident and migratory waterbirds. Ramsar’s designation account identifies Grey Pelican (now generally called the spot-billed pelican, Pelecanus philippensis) among the species of conservation concern reported at the site. Kolleru also supports capture and culture fisheries, agriculture and other occupations. Its seasonal flooding and recession shape both wetland habitat and the ways nearby communities use land and water. Historical biodiversity assessments summarized in the KBA factsheet recorded substantial bird and fish diversity, but those records should not be read as a current census.

Kolleru was designated a Wetland of International Importance under the Ramsar Convention in 2002. Ramsar’s site description emphasizes its location between the Krishna and Godavari basins, its role in flood balancing, its bird habitat and its support for fisheries and agriculture. The designation recognizes the wetland’s international significance; it does not imply that all ecological pressures have been resolved or that the site is insulated from changes in land use and water management.

Research on land-cover change at Kolleru used remote sensing and geographic information systems to compare conditions from 1977 to 2007. The study reported a substantial expansion of aquaculture farming during 1977–2000 and examined subsequent changes after fishpond demolition ordered by India’s Supreme Court in 2006. It argued that systematic wetland monitoring is necessary for management and for identifying changes to ecological character. The KBA site account also lists ongoing pressures including agricultural and aquaculture expansion, pollution, overfishing and other human activities. These sources describe findings and threats at particular times; conditions can change, so present-day management decisions require current field data and monitoring.

Kolleru’s shifting water extent is an ecological feature as well as a management challenge. High monsoon waters can inundate a broad floodplain, while lower water levels in dry periods expose areas used for other purposes. Planning must therefore consider seasonal hydrology, the connected river-basin landscape, wetland habitat and local economic uses together. Remote sensing can help track land-cover change over large areas, but interpretation benefits from on-the-ground ecological and community information.