Civil Insight: A Technical Magazine Volume 2 | Page 29

CIVIL INSIGHT 2018 TEACHERS’ SECTION 29 E-Flow: An Imperative Requirement for Sustainable Hydropower Development Er. Kshitiz Gautam Teaching Assistant Department of Civil and Geomatics Engineering, Kathmandu University [email protected] A primary challenge in sustainable development of water resources is preventing the loss of natural ecosystem services while designing and operating water infrastructures to provide social benefi ts. Table 1: Critical fl ow, depth and average velocity at different times at Kaudiyala, India (Upper Ganga) (O’Keeffe, Kaushal, Bharati, & Smakhtin, 2012) Month Critical Flow (m 3 /s) Depth (m) Average Velocity (m/s) Component January- maintenance 400 9.50 0.64 Fluvial Geomorphology August- maintenance 3250 21.05 1.15 Biodiversity January- Draught 290 8.28 0.57 Livelihoods August- Draught 1469 16.28 0.91 Biodiversity The table 1 above shows the critical fl ow (minimum required fl ow), its depth and the velocity at a section of Ganges River at a place named Kaudiyala near Rishikesh, Uttarakhand, India based on various parameters such as the fl uvial geomorphology, biodiversity, livelihood requirements at different conditions of normal fl ow years and drought years. The above recommendation was made on the basis of a research study conducted by WWF-India to determine the minimum required fl ow in the Upper Ganga River Basin in order to maintain the aquatic ecology, biodiversity, fl uvial geomorphology, religious activities and community use of the river in and around the periphery of the selected site. A question could arise: Why is such a study required at a place like that? That would be very easily answered by the numerous dams constructed upstream of the site like Maneri Dam and Tehri Dam which have blocked the natural fl ow of the river affecting the breeding habitat of Mahseer , a fi sh species, and the water requirement of the community at Hindu holy places like Rishikesh, Haridwar and Devprayag. The state of the biodiversity at Kaudiyala at the time of study was determined to be Class D/E (extensive to critical loss of habitats, biota and basic ecosystem functions) (O’Keeffe, Kaushal, Bharati, & Smakhtin, 2012) because the food web has been modifi ed due to the loss of habitat caused by human interventions, such as impoundments and diversions for multi-purpose river valley projects (For example: hydropower projects).