(a) As soon as practicable after organization of the irrigation district, the board shall by resolution entered upon its records, formulate a general plan for its proposed operation as approved by the chief engineer, in which it shall state what constructed work or other property is proposed to be purchased and the purchase price therefor, and/or what construction work it is proposed to do and the estimated cost of such construction, and shall state whether funds to pay such purchase price or costs of construction shall be raised by issuing bonds or by creating a fund through the collection of water rentals and charges or by creating a fund by levying assessments against the land benefited or from money received under contract with United States or its departments or agencies, or whether it is contemplated to raise funds by the use of all or a combination of such methods of raising funds.

(b) For the purpose of ascertaining the costs of any such construction work, the board shall cause surveys, examinations, and plans to be made as shall demonstrate the practicability of such plan and furnish the proper basis for an estimate of the cost of carrying out the same. All such surveys, examinations, maps, plans and estimates shall be made under the direction of a competent irrigation engineer and certified by him. The board shall then submit a copy of the same to the chief engineer for his approval. Upon receiving the approval thereof by the chief engineer, as submitted or with limitations or as modified, amended or supplemented, the board shall determine the amount of money required to be raised.