California Code, Health and Safety Code - HSC § 2044

(a) A district may cooperate with any public agency or federal agency to carry out the purposes and intent of this chapter. To that end, a district may enter into agreements with those other public agencies or federal agencies to take any and all actions necessary or convenient for carrying out the purposes and intent of this chapter.

(b) A district may jointly acquire, construct, improve, maintain, and operate any facilities, projects, or programs with any other public agency or federal agency to carry out the purposes and intent of this chapter. Nothing in this chapter shall be construed to prohibit any joint or cooperative action with other public agencies or federal agencies.

(c) A district may enter into joint powers agreements pursuant to the Joint Exercise of Powers Act, Chapter 5 (commencing with Section 6500) of Division 7 of Title 1 of the Government Code.