Protects, promotes, and preserves an environment that is conducive to public health and welfare; prevents the creation of nuisances and the depletion of natural resources; maintains such levels of air quality and water quality as will protect human health, welfare and safety; to the greatest degree practical, prevents injury to plant and animal life and property and nurtures the comfort of the people in their enjoyment of life and property; and encourages the social and economic development of the county and facilitates the enjoyment of its attractions.