Requires the governing body of each county and city, subject to certain limitations, to develop and adopt specific local ordinances outlining when and how alternative water systems may be used to satisfy potable water requirements.

Requires the department of ecology to make information available to landowners, unable to rely on an approved water purveyor or on new, unmitigated withdrawals from surface or groundwaters to satisfy certain requirements, that provides both mitigation options and information on alternative water systems.