This Article shall be known as the Water Efficiency Requirements for the construction of new buildings and the installation of new plumbing fixtures in existing buildings in the City. The purpose of this Article is to impose water efficiency requirements for the construction of new buildings and the installation of new plumbing fixtures in existing buildings to minimize the effect of any water shortages to the customers of the City; and, by means of this Article, to adopt provisions that will reduce the consumption of water over an extended period of time, thereby extending the available water required for customers while reducing hardship on the City and the general public to the greatest extent possible, voluntary conservation efforts having proved to be insufficient.