A newly formed water and power company managed by a San Diego housing developer is negotiating behind the scenes with the City of Industry on the future of 2,500 acres of undeveloped rolling hills near the borders of Los Angeles, Orange and San Bernardino counties. The business-centric City of Industry has been aggressively trying to regain control of the historic Tres Hermanos Ranch in Diamond Bar and Chino Hills, one of the largest remaining pieces of vacant private land in the region. The city lost access to the land during the demise of local redevelopment agencies five years ago.