New rules floated by California water regulators would force utilities to sell less water at a time when it is becoming more difficult for them to raise customer rates, credit ratings agency Fitch said on Monday. “Water rates have risen faster than incomes. If this trend continues, Fitch would expect that overall rate flexibility – the ability for utilities to raise rates – could be tested,” it said in a note. California has been in the grip of a drought since 2013 that has cost the state’s agricultural economy billions.