The Tidal Link Drain is a man made drain which delivers the drainage
water across Pateji and Cholri Dhands into the Arabian Sea via Shah Samando creek. The
Tidal Link is 41 Km long from its point of juncture with Kaddan Pateji Outfall Drain
(KPOD) in the North-East up to Shah Samando Creek in the South-West. The vertical
tidal range in the area is about 5 m. The tidal link was designed to carry about 3,118
cusecs of drainage waters. After completion of Tidal Link Drain, sea water intrusion and
high erosion/sedimentation have been noticed at the tidal link and adjacent area due to
changes in the hydraulic regime in the area. The devastation caused by tropical cyclone
“2A” in May, 1999 in the Indus delta has also created some drastic morphological
changes in the area. This physical process creates breaches in the Tidal link drain
between RD-30 and RD-125. These openings allow free exchange of water between the
tidal link drain, Dhands and the Rann of Kutch.
The analysis of tidal behavior, tidal current measurements and water samples
collected in the study area shows that a small tidal creek type system of drainage
channels has now been developed in Cholri Dhand and this system of channels is now
used to flush water during ebb tide from surrounding Dhands of LBOD through Tidal
Link Drain. It is observed that the LBOD can now be described as a “New River” that is
forming an “Estuary”, which is an integral part of the creek system of the coastal area.
The tidal link now acts as a tidal stream in which tidal fluctuations are very much visible
and the sea water is now approaching the land. The main problem concerning the LBOD
outfall is the increased hydraulic gradient due to seawater intrusion. The LBOD run
parallel to the Indus River and discharges the saline water at the same level (sea level) in
an active creek area of the Shah Samando Creek. The same altered hydraulic gradient
creates very strong ebb currents in the region, which are responsible for making breaches
in the tidal link drain and erosion and accretion in the Dhands