Harassment from Irrigation Dept AE - Need legal opinion

Dear Sir/Madam, I bought a piece of agriculture land of 3 acres patta land with clear title in nalgonda dist in 1987. I then built a house on centre of my land in 1993 after taking necessary permissions from local Govt body/ Village Grampanchayath and paid property taxes till today I.e 2017 march. last month Irrigation AE came to my land and said 3 meters Nala route is going through my land. I then happily agreed to make nala from my patta land , but he said it is also going through my house built in centre of land. I requested him to take nala beside compound wall of house from my own patta land itself as I am ready to compensate land for it so that my hard earned house cannot be demolished. But AE threatened me that this is mission kakatiya program and I'll demolish your house even you had approvals from local govt, but he said he will agree to move nala route beside my compound wall only if I pay him 3 lakhs rupees bribe. kindly help me on how to proceed here as i was getting harassed from irrigation AE.