The L.A. DWP, which agreed in 1997 to fight dust pollution from part of the dry Owens Lake bed, wants to rework the deal and balks at an order to take responsibility for more territory.LONE PINE, Calif. — Los Angeles and the Owens Valley are at war over water again, with the city trying to rework a historic agreement aimed at stopping massive dust storms that have besieged the eastern Sierra Nevada since L.A.