The effectuation of the powers authorized by the Flood Control District Act shall be in all respects for the benefit of the people of the state, including but not necessarily limited to those residing in any district exercising any power under that act, for the improvement of their health and living conditions and for the increase of their commerce and prosperity. Thus, no district shall be required to pay any general (ad valorem) taxes upon any property appertaining to any project authorized by the Flood Control District Act and acquired within the state, or the district’s interest therein.