Environmental flows: Moving from concepts to implementation in South Asia

May 06, 2020.  

Demand for freshwater to fulfill the diverse societal and developmental needs of domestic, agricultural, industrial and commercial sectors continues to rise. This situation has led to plans to harness evermore water resources from rivers and streams.

When we talk about environmental flows we describe the quantity, quality and timing of the water flows needed to sustain freshwater ecosystems as well as the benefits they provide to humans, such as fresh water, fish and other aquatic species, flood control and climate change mitigation. Many people in non-industrialized countries directly depend on such ecosystem services for their livelihoods and well-being. The overuse of water and continuing degradation of aquatic ecosystems therefore reduces the well-being and livelihood options for many people.

Ecological signifance of hydrological regime components

All components of the natural hydrological regime have a certain ecological significance. In regulated basins, the magnitude, frequency, and duration of some or all flow components are modified. Such modifications should ideally be limited to the protection of aquatic habitats and ecosystem processes. A compromise must therefore be found between river conservation and river development, including dam construction. The science of environmental flows is a rapidly advancing field. New concepts, methods and tools are added to an ever-expanding knowledge base.

India's first environmental flow assessment was in 2007

Although there is general acceptance and agreement on the importance of maintaining river health, there is still a lack of clarity on the implementation and enforcement of environmental flows, especially in South Asia. India’s first-ever holistic environmental flow assessment was conducted on the iconic Ganges River in 2007. In addition to taking into account ecological water requirements, the project examined livelihood, spiritual and cultural needs, including the volume of water required for ritual purifications. This was the first time that “spiritual flows” were included in an environmental flow assessment. This endeavor raised a lot of interest within government agencies and was supported by the National Clean Ganga Mission. Nevertheless it did not translate into concrete environmental flow policies and regulations. In Nepal, another country in South Asia, environmental flows are now mentioned in national level policy documents such as the Irrigation Master Plan but there is as yet no enforcement of environmental flows in river management.

Efforts made so far are not enough yet

In the last decade, environmental and research organizations in South Asia have succeeded in bringing the idea of environmental flows into river management practices. However, more efforts are needed to move from concept to actual implementation through policies and regulations.



About the author

Luna Bharati is a principal researcher for the International Water Management Institute (IWMI) and based at ZEF.
Contact: L.bharati[at]cgiar@org


This article is from ZEFnews 40. For the full issue see:





Luna Bharati

Dr. Luna Bharati


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