witch Flint's water supply from the Detroit water system to the highly corrosive Flint River. March 2013 flint recieved their water supply from Detroit Water and Sewerage Department, but were in the process of negotiating with Karegnondi Water Authority, a regional water authority that was in the process of building a pipeline from Lake Huron. Detroit then sent a letter of termination of contract, for 1 year out, allowing for renegotiation of costs. Flint found the cost of renegotiation as too high, and the Karegnondi water deal would take almost 3 years so they had to do something. they decided to use the flint river as a water source.