By  Lori Valigra  and  John Upton The city of Bath, nestled on the western banks of the Kennebec River, is especially endangered by climate change and rising sea levels. Credit: Troy R. Bennett / BDN BATH, Maine — Peter Gerard had never seen so much water. A torrential rain storm in late September 2015  coinciding with high tide waters and leaves clogging drains sent him racing to a low-lying Central Maine Power Co. substation near the Kennebec River to check equipment. The water was already 2 feet deep, so he could not get too close. Gerard, an electromechanical worker and 33-year veteran of the electric utility, called the substation’s operations director, who decided to shut off power to the utility’s 4,000 customers in and around the midcoast city. That included Bath Iron Works, a shipyard across the street that is one of Maine’s largest private employers and that the U.S.…