land issue

Sir, I Rajesh Kumar Paswan resindent of Khardah, Kol-700119, working in defense services. My father had purchased a land in khardah, Raskhola, lahabagan area near Gabtala maidan in jan 2013. We registered the name on my father's name Rajkumar Paswan. We were planning to start the construction of our house shortly. After one month , we got a Verbal notification from khardah municipality regarding construction of water tank beside our land, in which khardah Municipality asked us to stop the construction of our house for a time period(Tentative) of one year. Currently the construction of water tank has been completed. When we visited our land after the water tank construction, we found out that the roof of the water tank is touching the corner of our land. Also the pipeline of the water tank is passing inside our land by 6 feet inside the common pathway. The land which we registered during the purchase, they have build the water tank and in compensation of that land they gave us a land next plot to it. Now since the construction of the water tank is finished, so we requested Khardah Municiplaity to allow us to start construction of our house on the plot, but they are simply denying it.