In many areas, shallow dug wells have dried up and farmers are now drilling multiple bores alongside or within existing dug wells. Wells in Tamil Nadu are increasingly shifting from single owners to joint ownership. Over 60 percent of well-owners in Tamil Nadu are small and marginal farmers with landholdings of less than 5 acres. Their economic survival is threatened by groundwater pollution and overdraft. Decline in water level and pollution is affecting the availability and reliability of water supply for irrigation and other uses. Farmers have responded to this water scarcity by adopting efficient water use technologies. In the Noyyal basin, the costs per hectare are far higher — approximately 4.7 times what the government has spent to create one hectare of irrigation potential under major and medium irrigation projects. Rice and other cereals are being exported as well.