The aqueduct was sold to the citizens of Los Angeles as vital to the growth of the city. Unknown to the public, the initial water would be used to irrigate the San Fernando Valley to the north, which was not at the time a part of the city. From a hydrological point of view, the San Fernando Valley was ideal: its aquifer could serve as free water storage without evaporation. One obstacle to the irrigation was the Los Angeles City Charter, which prohibited the sale, lease, or other use of the city's water without a two-thirds approval by the voters. This charter limitation would be avoided through the annexation of a large portion of the San Fernando Valley to the city. The annexation would also raise the debt limit of Los Angeles, which allowed the financing of the aqueduct.