‘Riverbed mining would compromise durability of new bridge over Chathe’

'Indiscriminate scouring has decreased river bed level of Chathe river by 20 feet in 30 years since construction of the old bridge'

Morung Express News
Dimapur | July 26

The Chathe River Bridge which is under construction and due for completion by early 2020 may not live long if riverbed mining activities continue. 

This concern was raised by Executive Engineer, Dimapur Division (R&B), Er Talitemsu Jamir, who pointed out that extraction of sand, sand gravel mining and boulders both upstream and downstream was one reason which led to the collapse of the Chathe River Bridge on July 11, 2017. Four person were killed. 

The two-lane bridge, measuring 100m in length and 12.75m in breadth, over the Chathe River is slated for completion by April 2020, although the initial target was December 2019. 

The initial estimated cost of the project was Rs 3765.99 lakh (37.64cr) but this is also likely to escalate owing to rise in price of construction materials and transportation. 

A total amount of Rs 8 crore has been released so far and 60-65% of total works has been completed. While the work order was issued in 2016, the works started in October 2017 and the delay was attributed to land acquirement issues.

Er Talitemsu informed that the rate of scouring is such that the river bed level has decreased by about 20 feet in 30 years since construction of the old bridge.  “Even if the new bridge is completed, if mining activities continue, it would compromise the durability of the infrastructure,” he added. 

He stressed that sand gravel mining activity needs to be restricted at least 1km upstream and downstream of the new bridge. He also said weirs (a kind of dam) had to be constructed downstream to maintain the river bed at a desired level.

The struggle over riverbed mining at Chathe and Dhansiri, the two major rivers that flow through Dimapur have been going on for years. Despite government notifications banning unauthorized riverbed mining, the same have been going on rampantly, compromising not just the water that flows in it but its entire ecosystem.  

Even though the Dimapur district administration has constituted an enforcement committee to look into rampant mining and extraction of sand, sand gravels and boulders in the Dhansiri and Chathe rivers, activities have been reportedly going on in the sly. 

As a consequence of indiscriminate mining of riverbeds at Chathe River, a number of public and private properties in the area have been washed away mainly due to bank erosion. Of the most recent, in 2018, four houses and a granary located by the Chathe River were reported to have been washed away during monsoon.