Environmental Engineering Reference
In-Depth Information
Conclusions
River Ganges originates from Gomukh in Uttarakhand, India. Uttarakhand, a state
located in northern part of India is also referred to as an “Energy State” because of the
potential that it possesses for generation of hydro-electric power. This potential is due
to the immense number of streams/rivers in this state and their perianal nature due to
their origin in snow clad mountains of Himalaya. Approximately 18 hydroelectric
projects have been planned in Tehri and Uttarkashi districts on this river, a region
within 100 km of its origin. Like most of the sites for hydro-electric power projects, at
Maneri Bhali (Phase I), reservoir water is diverted into tunnels and stretch(s) of river
after dam wall has drastically reduced water levels. Temperature before dam wall
ranged from 14.46 ﾱ 0.99 ﾰC to 10.46 ﾱ 0.73 ﾰC while after the dam wall it ranged from
17.00 ﾱ 1.16 ﾰC to 12 ﾱ 0.80 ﾰC. Before dam average CO
2
range was 2.71 ﾱ 0.27 mg/L
while after dam it was 3.09 ﾱ 0.32 mg/L. DO before dam wall was 10.02 ﾱ 0.30 mg/L
while after dam it became 8.42 ﾱ 0.30 mg/L. Population of ishes (mostly
Schizothorax
)
was estimated at 44 ﾱ 6 ishes before dam while it was 21 ﾱ 3 ishes after wall. All the
variations were significant. Absence of phytoplankton and zooplankton species was
also recorded after dam wall. The overall situation in areas after dam wall needs imme-
diate attention for habitat restoration. Besides the Ganges and the Yamuna, there are
many other rivers that are tributaries of these two rivers. Policy makers in Central
Government and the State Government have marked several hydro-electric projects in
many of these rivers. Environmentalists have objected to the clearance of these proj-
ects because the project report on paper differs widely from the ground realities in
terms of minimal water flow policies. The river water flow after every dam wall is so
drastically changed that it is impacting the river ecology. The present study reports one
such startling finding where there are significant alterations in physico-chemical prop-
erties of water before and after the dam wall have altered along with the aquatic fauna.
It is a wakening call for the policy makers; we still have time to save a region if we act
now. Further long-term studies will also have to be undertaken to keep a baseline date
for year to year variations that might occur.
Acknowledgement
Funding for Major Project from University Grants Commission (UGC), India
(grant number - F.No. 40-372/2011 (SR) dated 5th July, 2011) to Dr. Madhu Thapliyal is duly
acknowledged.
References
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American Public Health Association (1992) Standard methods for the examination of water and
waste-water, 18th edn. APHA, Washington, DC
Badola SP (2009) Ichthyology of central Himalaya. Transmedia Publication
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