Civil Insight: A Technical Magazine Volume 2 | Page 31

CIVIL INSIGHT 2018
TEACHERS’ SECTION
31
association to the people’s lives to support culture and spirituality or livelihoods or biodiversity or all the above
functions and more; technical, because it requires a range of specialist investigations into past, present, and
desired future river functioning to provide the data that will inform and support these choices. Thus, e-fl ow
assessment (EFA) is a multidisciplinary exercise where local stakeholders play a key role.
Considering the hydropower projects, the typical objective of determining E-fl ow for a project is to ensure an
optimum balance between energy generation and preservation of river ecosystem. Lives of many communities
along the stretch are sustained on the river products. These ways of life may include fi sheries, livestock,
agriculture, tourism, socio-cultural beliefs, which get disturbed when the fl ow is obstructed. As hydropower
project uses up or blocks a major portion of discharge of river, it is most necessary to fi nd the balance point
between the environment and development. It is of utmost importance to regulate the minimum fl ow required
for sustainability of the socio-economic and environmental activities of the river.
Over a course of time, Nepal has developed different provisions for environmental protection, moreover,
ecological protection of the river system:
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Before 1992, there was no mandatory requirement for environmental protection.
The Water Resources Act in 1992 initiated the consideration of environmental protection during
development project.
The introduction of the Environment Protection Act (EPA), 1997 states the need for carrying out the
Initial Environmental Examination (IEE) and Environmental Impact Assessment (EIA) for projects based on
their installed capacity.
The Environment Protection Rules (EPR, 1997) which is based on the EPA made it mandatory for projects
above 50 MW to conduct an EIA study and for those below 50 MW, an IEE study was required.
However, the Hydropower Development Policy introduced in 2001 specifi cally mentions theamount of
minimum fl ow that must be released. It states that “Downstream release shall be maintained, either
10% of minimum mean monthly discharge or the quantum identifi ed in the EIA study whichever
is higher” and “Implementation of Environmental Impact Assessment (EIA) recommendations shall be
emphasized.”
Thus, all projects licensed after 2001 require a minimum fl ow criterion. This fl ow is derived using a traditional
hydrological method which calculates a fi xed percentage of the mean monthly fl ow or minimum mean monthly
fl ow in the dewatered section of the river. This method does not account for the natural variability of fl ow in
the river. Here arises a major question: Does the provision of releasing 10%to the downstream address the
minimum requirement of fl ow for maintaining the river health?
To fi nd an analogical answer to this question, the case of Kaudiyala would be helpful. From fi gure 4 below, we
can visualize that the released fl ow from the dam u/s the site or to say the available fl ow at the site seems to be
insuffi cient during the fi rst 6 months of low maintenance period (fl ow during the drought years). So, it is clear
that the fl ow released, which is less than the natural fl ow and even less than the minimum fl ow requirement
is insuffi cient for the good river health, which is verifi ed by the decreasing BOD of the river. This makes it more
evident that the mechanism being followed for releasing the environmental fl ow has some loopholes.
Figure 4: Flow volume of various conditions versus month of fl ow at Kaudiyala (Upper Ganga)(O’Keeffe,
Kaushal, Bharati, & Smakhtin, 2012)