A conceptual framework for environmental flows assessment based on ecosystem services and their economic valuation

- Alteration of flow regimes affects various ecosystem services differently.
- EFlows assessments should consider all ecosystem services and their economic value.
- A top-down approach should be used for valuation of impacts of flow alteration.

In recent decades, environmental flows has emerged a major instrument for sustaining and/or rehabilitating the ecosystem functions and services of rivers worldwide. The holistic methodologies of assessment of environmental flows (=EFlows) take into account the physical, biological, water quality and socio-cultural as well as livelihood aspects of riverine ecosystems, and increasingly depend upon consultations with experts and local communities to make a negotiated socio-political decision by consensus within the society. This paper presents a conceptual framework for the assessment of EFlows on the basis of a change in total ecosystem services and their total economic value with the alteration of flow regimes. Such an assessment would consider the gain and loss of ecosystem services both upstream and downstream of the point of intervention which alters the flow regime. It is also proposed that the economic valuation should provide for appropriate weightages to ecosystem services with a strong social, cultural and livelihood bearing in regional/local context. It is further argued that a top-down approach to E-Flows assessment should be followed wherever possible to convince the policy makers.