municipality stormwater basin overflowing and flooding my garage and basement.

I purchased land and built a new home in with a down slope driveway in 2010. After 1 month of living there I came home to find my garage and basement were flooded due to overflowing stormwater basin. A few days later I went in front of the planning board and told them what was happening. They told me that the street has always flooded for the past 30 years. I dont understand why they would approve a home plan with a down slope driveway knowing the street floods. I thought planning board members are they to protect home builders from making mistakes. Anyway.. I filed for notice of claim a few days later, I have met with town engineer and head of dpw, its been 3 years now and they still can not fix problem. I dont know what type of attorney I need but i need to do something. Please review and advise