Framework for lake rejuvenation to make process ‘technically sound and locally owned’

Lake rejuvenation, the process of improving the condition and functioning of a lake so that it can achieve target functions such as flood mitigation, recharge, storage for indirect potable reuse, and ecological or social services, often see interventions focused on outputs, such as installation of flood control infrastructure in a lake, rather than prioritising outcomes, like the flood control function performed by the waterbody.

A new Framework for Lake Rejuvenation aims to fix this with a five-stage, structured, science-backed, and community-informed roadmap for rejuvenating urban and peri-urban lakes: diagnosis and visioning, design, implementation, operation and maintenance, and monitoring and evaluation.

“Often, there is a lack of consensus among stakeholders about the goals, with scientific objectives taking precedence certain times, and community perspectives being prioritised at other times. A lack of design, construction, and operational standards leads to a range of undesired consequences. Though water quality is assessed using a discrete system, varying use require a continuous scale to reflect increasing sensitivity and to ensure consistent evaluation across lake water uses. Fragmented planning, unclear responsibility, and a lack of understanding of cause-effect relationships between management actions and changes in the lake make it challenging to connect specific lake interventions to observed outcomes,” noted a document. “Each step is designed to bring scientific and technical assessment into direct dialogue with the aspirations of the communities who depend on these waterbodies, so that rejuvenation efforts are both technically sound and locally owned,” stated a release.

Prepared by WELL Labs, in collaboration with Friends of Lakes and several other stakeholders, a broad coalition of research institutions, civil society organisations, government agencies, and citizen groups, the framework, launched on Sunday, particularly focuses on urban and peri-urban, tropical shallow lakes. It specifically addresses freshwater lakes in peninsular India.

“Their maximum depth is six metres, so light can potentially penetrate to the bottom. These lakes, therefore, are non-stratifying; that is, they lack vertical density segregation. These dynamic systems are often located in densely populated areas, where human impact is significant. They face pressures from domestic and municipal sources of pollution. The framework specifically excludes lakes receiving industrial sources of pollution because such contamination involves complex chemical pollutants and heavy metals. These require specialized, often costly, remediation techniques that differ significantly from the nutrient and organic matter management approaches,” it stated. At the launch event, V. Ramprasad, co-founder, Friends of Lakes, and president, Federation of Bengaluru Lakes, said, “The visioning process should highlight the aspirations of impacted stakeholders and secure their buy-in before a project begins,” adding that impact reporting cannot rely on a single metric (such as the quantity of water stored in a lake), but must instead account for hydrological, water quality, and ecological factors together.

Stressing that lakes should not be considered in isolation, Sujata C. Hingorani, principal and founder-partner, OASIS Design International, emphasised that rejuvenation must take a systemic view, “as interventions may affect something downstream or elsewhere.”