Any person, by an action brought pursuant to the provisions of this part, may submit any contract or proposed contract entered into, or proposed to be entered into, by such person under the provisions of this part to the superior court of either the county in which such person resides or in which such person has its principal office for the transaction of business or in which such contract was made or is to be performed in whole or part, to determine the validity of such contract and each and all of its terms and provisions, and the authority of such person to make and perform the contract, and the authority for and validity of any purchase, acquisition, sale or conveyance under the contract; provided, that if the contract provides for a water supply such decree shall not be construed to be an adjudication that the United States owns, or does not own, such water supply.