Trapezium trenches now to prevent jumbos from straying out of forests

Chamarajanagar: With the previously designed Elephant Proof Trenches (EPTs) on forest boundaries, which were two-metres in depth, not serving the purpose of preventing elephants from straying out of forests, forest officials have made the trenches one metre deeper which has been of immense help in preventing jumbos from crossing forest areas in Biligiriranga Hills, a tiger reserve in Chamarajanagar district. 

“The EPTs are shaped like a trapezium,” said Assistant Conservator of Forests, Ruthren, giving the dimensions of the EPTs in which the surface width is  three-metres, depth three metres and the bottom depth is a metre and a half. Explaining why the two-metre depth EPTs failed to stop elephants from going out of the forests, Ruthren said  wild boars were the first to show the way for bigger animals such as elephants a route to enter fields and villages in search of fodder and water by crossing these trenches. Further, silt formation in EPTs helped elephants cross trenches easily. But, with deeper EPTs in place, elephants have struggled to get out of the reserve, he added. 

By digging deeper EPTs in Chamarajanagar range of 11.5 km and Punajoor range of three-km in BR Hills, incidents of elephants crossing into fields have come down drastically, Besides, digging EPTs is cost-effective compared with putting up rail barricades on the forest borders.

“Installing a km of rail barricade costs around Rs 1.3 crore but digging EPTs costs much less- Rs 17 to Rs 20 lakh for a km,” said Ruthren who added that work on EPTs happen faster than rail barricading. More vulnerable points in the reserve are being identified to dig deeper EPTs. 

Chamarajanagar Range Forest Officer Rathan Kumar said such deepening of EPTs was done in Bandipur and Nagarahole National Parks and the same model was emulated to bring down incidents of jumbos straying out of the reserve. 

A conservationist told Deccan Chronicle that whatever is the design of the EPT, they serve the purpose for about a year and later on, silt gets accumulated or villagers fill up the EPTs to help their cattle graze in forest areas. The same route will be used by jumbos to stray out of the Park unless EPTs are properly maintained, he said.