A source water protection ordinance is used by cities and counties to address proposed and existing development and potential water quality impacts. The ordinance maps the resource as a protection area and requires specific land use and development within the boundaries. The ordinance could apply to the whole protection area or different restrictions could apply to specific zones of sensitivity. Source water ordinances may include some or all of the following:

-  Prohibit land uses, such as landfills, underground fuel storage tanks, or animal feeding operations.

- Enact subdivision controls, such as limiting septic system density by requiring larger lot sizes, and special permit or site requirements such as limiting use of toxic and hazardous materials, pesticides, and salts.

- Require performance standards, such as secondary containment for petroleum or chemical storage over a certain volume or erosion control that includes establishing vegetative cover with a certain number of days after construction completion.

Additionally, source water protection best management practices may require variances from current ordinances, such as current subdivision design requirements that may not allow departures from typical subdivision designs (e.g., street widths, sidewalk exclusions, and downspout requirements).