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The Narmada Main Canal (NMC) also known as Navagam Main Canal off-takes
from Sardar Sarovar Dam in Gujarat at a full supply level (FSL) of 91.44
m (300 ft.) and traverses through a distance of 458.412 km before entering
Rajasthan near village Silu, Tehsil Sanchore, district Jalore. The section
of the main canal at head & tail is 73.1 m x 7.6 m and 10.3 m x
4.4 m respectively with side slopes of 2:1. It is provided with 1.25
m lined freeboard and 0.25m bank freeboard at head and tail respectively.
The bed slope of the canal is 1:12500 from km 0 to 144.5 of NMC and
1:15500 there after, up to the Gujarat-Rajasthan border. The entire
length of NMC is to be lined with M-15 grade controlled concrete. There
are 196 structures on the main canal up to km 144.5, and in all about
600 structures up to its tail end. The entire main canal portion in
Gujarat is planned to be completed in two phases. Phase - I of the main
canal envisages construction up-to Ch. 144.5 km (i.e. upto Mahi river
crossing) and the remaining reach from Mahi river crossing up-to Ch.
458.412 km (i.e. upto Gujarat-Rajasthan border) will be covered under
Phase - II.
There will be 42 branch canals having a total length of 3500 km (including
sub-branches) taking off from NMC with discharges reducing from 320
cumecs to 3 cumecs. The major branches of the system are Miyagam branch
(86.66km), Vadodara branch (115.00km), Saurashtra branch (104.60 km)
and Kachchh branch (329.18 km). The largest branch in capacity is the
Saurashtra branch, which negotiates a series of falls and lifts. The
Kachchh branch crosses a depression connecting Little Rann of Kachchh.
This depression is planned to be negotiated through falls and lifts.
Distribution system will comprise of 7500 km of distributaries and nearly
30000 km of minors and sub-minors. The aggregate length of the distribution
network including field channels will be about 75000 km.
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