The board may institute any proceedings and acquire all real property necessary therefor on such terms and conditions as it deems advisable.
Whenever the cost of construction of any project or the cost of any repairs thereto shall exceed two thousand five hundred dollars ($2,500), such work shall be done by contract, and any contract therefor shall be void unless the same shall be let in the manner provided by Sections 25451 to 25455, inclusive in the case of a county, and Sections 37903 to 37907, inclusive, and Sections 37931 to 37935, inclusive, in the case of a city.