Cal. Wat. Code § 11915.5
For the purpose of furthering recreation in any project of the department, the department may exchange any real property it has acquired for property in the state owned by the United States which is of substantially equal value, whether or not such real property of the United States is adjacent to or needed for any project of the department. Such title or rights as the department deems necessary for the proper operation and maintenance of the water conservation, flood control or power features of any water project shall not be included in any exchange consummated under this section.
Any such exchange involving real property acquired by the department solely for recreation shall be concurred in by the Department of Parks and Recreation. Any such exchange involving property acquired by the department solely for fish and wildlife purposes shall be concurred in by the Department of Fish and Game. Any such exchange involving property acquired solely for fish, wildlife and recreational purposes shall be concurred in by the Department of Fish and Game and the Department of Parks and Recreation. Real property of the United States not necessary for a project of the department shall be acquired by the department by exchange under this section only if another agency of state government has agreed to acquire such real property from the department for the actual cost to the department of the real property which is to be given in exchange therefor; provided, that any amount appropriated to the department to reimburse it for prior expenditures for acquisition of such land shall be deducted from the actual cost.
Ca. Water Code § 11915.5