It is hereby declared that recurrent floods on rivers and streams of this State, causing loss of life and damage to property, disruption of commerce, interruption of transportation and communications, and wasting of water, are detrimental to the peace, health, safety and welfare of the people of the State. The control and prevention of such floods and the loss and damage caused thereby and the conservation and protection of the State’s land and water resources are proper functions and activities of the State, in cooperation with counties, cities, state agencies and public districts, and in cooperation with the United States, or any of its departments or agencies.