Increasing incidences of open well subsidence during monsoon has become a major concern for the people in Wayanad.
More than 10 such incidences, mainly from Vythiri and Mananthavady taluks, have been reported in the district in two months this year.
Sinking of open wells was rare in the region, but such incidences have increased after the floods in 2018, said the farming community. Most of the wells were destroyed fully during the deluge.
“The district comprised thousands of hillocks and valleys or plains. Those plains are basically marshy land, which were later converted to dry lands either for construction of buildings or for planting cash crops,” former District Soil Conservation Officer P.U. Das said.
Those marshy lands were formed due to the meandering nature of brooks and rivulets and they had deposited alluvial soil during monsoon for the past many centuries, Mr. Das said.
The depth of topsoil on hills in the district is comparatively larger than other districts in the State and the intensity of rain revived the marshy nature of the soil. Moreover, the clayey, gravelly, red earth seen in those areas causes high infiltration and seeping of water, he said.
The flow of the water was blocked after the conversion of land and it created a marshy nature of soil beneath the hill surface. “The increased weight of soil owing to water saturation led to incidences of well subsidence,” Mr. Das said.
Unscientific land use, destruction of the topography of streams, mining for construction of houses and buildings, and loss of balance of hills after earth cutting on the toe of hills for constructions also accelerated the phenomena, he added.