A city or county must adopt a "comprehensive, long-term general plan" for its physical development. (Gov. Code, 65300.) The general plan must include "a statement of development policies and ... objectives, principles, standards, and plan proposals" and elements addressing land use, circulation, housing, conservation, open space, noise, and safety. (Gov. Code, 65302.) The general plan serves as a "charter for future development" ( Lesher Communications, Inc. v. City of Walnut Creek (1990) 52 Cal.3d 531, 540) embodying fundamental policy decisions ( Citizens of Goleta Valley v. Board of Supervisors (1990) 52 Cal.3d 553, 571, 276 Cal. Rptr. 410, 801 P.2d 1161). A general plan and each of its elements must "comprise an integrated, internally consistent and compatible statement of policies for the adopting agency." (Gov. Code, 65300.5.) Zoning and other decisions affecting land use and development also must be consistent with the general plan. (Gov. Code, 65860, subd. (a); Citizens of Goleta Valley v. Board of Supervisors, supra, 52 Cal.3d at p. 570.) Local governments have a responsibility "to facilitate the improvement and development of housing to make adequate provision for the housing needs of all economic segments of the community" and must "cooperate with other local governments and the state in addressing regional housing needs." (Gov. Code, 65580, subds. (d), (e).) To that end, the housing element of a general plan must identify and analyze existing and projected housing needs, must include "a statement of goals, policies, quantified objectives, financial resources, and scheduled programs for the preservation, improvement, and development of housing," and "shall make adequate provision for the existing and projected needs of all economic segments of the community." (Gov. Code, 65583, 1st par.; accord, 65583, subd. (b)(1), (2).) The housing element must contain a five-year program to "achieve the goals and objectives of the housing element through the administration of land use and development controls." (Gov. Code, 65583, subd. (c).) The program must identify adequate sites with services and facilities that will be made available for "the development of a variety of types of housing for all income levels ... in order to meet the community's housing goals ...." (Gov. Code, 65583, subd. (c)(1)(A).) The housing element must include an inventory of sites suitable for residential development and an analysis of the zoning, public facilities, and services available for those sites. (Gov. Code, 65583, subd. (a)(3).) If the inventory of sites does not identify adequate sites to accommodate the need for housing for persons of all income levels, the five-year program must provide for sufficient sites to be zoned for multifamily residential use to accommodate very low and low income households. (Gov. Code, 65583, subd. (c)(1)(A)(i).) If the total housing needs exceed the available resources and the community's ability to satisfy the need, the quantified objectives need not equal the needs but must be the maximum number of housing units that can be constructed, rehabilitated, and conserved for each income category. (Gov. Code, 65583, subd. (b)(2).) Thus, the five-year program must identify a sufficient number of sites that will be made available through appropriate zoning and development standards to meet the city's quantified objectives for housing for all income levels. (Cf. Hoffmaster v. City of San Diego (1997) 55 Cal.App.4th 1098, 1111.) Moreover, if the program does not identify sufficient sites to satisfy the need for housing for all income levels, it must identify sufficient sites to be zoned for multifamily housing for very low and low income residents. (Gov. Code, 65583, subd. (c)(1)(A)(i).) In addition to these requirements, a city must "designate and zone sufficient vacant land for residential use with appropriate standards" to meet the housing needs identified in the general plan. (Former Gov. Code, 65913.1, Stats. 1980, ch. 1152, 10, p. 3796.) "Appropriate standards" means densities and other requirements that "contribute significantly to the economic feasibility of producing housing at the lowest possible cost given economic and environmental factors, the public health and safety, and the need to facilitate the development of housing for persons and families of low or moderate income." (Ibid.)