Neighbor blocked drain.

We live in a row house. There is drain water flowing behind th house for last 23 years. House A water goes through House B(my house) and then goes thru House C and to a larger drain. House C stopped this flow by cementing and all the water flowed into my house and flooded my house upto 1 feet. All items where soaked cos of this. But same time there were electric sockets which where just 1.5 feet above ground. If something had happened to my family's life who would be responsible. I called up the local police and they came and unblocked the drain but did not take any action against House C. House C had earlier disputes against us and the local police had got them in writing that they will never trouble us 13 years ago. They have been threatening us over the last 6 months that they will kill us. We kept pateint to avoid any trouble for all. Now can I go ahead and complain that this is an attempt to murder. Why dint the police dint arrest House C members for what they had caused. ? What if we had lost our life cos of the electric shock that could have happened? Pls advise