The Chesapeake Bay Preservation Act (Bay Act) was enacted by the Virginia General Assembly in 1988 as a critical element of Virginia's nonpoint pollution source management program.  
The purpose of the Bay Act program is to protect and improve water quality in the Chesapeake Bay by requiring the implementation of effective land use management practices. 

As recognized in the Bay Act:

“Healthy state and local economies and a healthy Chesapeake Bay are integrally related; balanced economic development and water quality protection are not mutually exclusive.”

The Bay Act program is the only program administered by the Commonwealth of Virginia that comprehensively addresses the effects of land use planning and development on water quality. The Bay Act recognizes that local governments have the primary responsibility for land use decisions and expands their authority to manage water quality, and establish a direct relationship between water quality protection and local land use decision-making.

Under the Bay Act framework, the Chesapeake Bay Preservation Area Designation and Management Regulations were originally adopted in 1989, and amended in 1991, 2001, 2012, 2020 and 2022. The Regulations provide the required elements and criteria that local governments must adopt and implement in administering their Bay Act programs. Local Bay Act programs include:

1. A map generally depicting Chesapeake Bay Preservation Areas (CBPAs).
2. Performance criteria applying in CBPAs that pertain to the use, development and redevelopment of land.
3. A comprehensive plan that incorporates the protection of CBPAs and quality and protection of waters in the locality.
4. Zoning or other ordinance that incorporates measures to protect the quality of state waters within CBPAs and requires compliance with the performance criteria.
5. A subdivision ordinance that incorporates measures to protect the quality of state waters in CBPAs and assures that all subdivisions in CBPAs comply with the performance criteria.
6. A plan of development process prior to the issuance of a building permit to assure that the use and development of land in CBPAs is accomplished in a manner that protects the quality of state waters.
7. Publishing on its website the elements and criteria adopted to implement their local plan

Under the Bay Act and Regulations, DEQ’s primary role is to provide local program oversight, policy guidance and technical assistance when requested or otherwise required. Each of the 84 Bay Act localities has a DEQ program contact, or liaison, who provides one-on-one assistance as needed, as well as assistance with program compliance reviews.  

The Bay Act is one of the enforceable programs in Virginia's Coastal Zone Management Program. As such, DEQ’s Office of Environmental Impact Review reviews proposed state and federal projects or activities for consistency. State agencies are required to be consistent with local comprehensive plans and ordinances adopted to comply with local Bay Act requirements. Similarly, the federal Coastal Zone Management Act requires actions undertaken by federal agencies that have reasonably foreseeable effects on any land or water use or natural resource of the coastal zone (also referred to as coastal uses or resources, or coastal effects) to be consistent with a coastal state's federally approved Coastal Zone Management Program. Plans for state or federal projects, or activities are reviewed by DEQ for consistency with Bay Act requirements in lieu of review by localities. The exception is private development projects receiving federal funding, which are also reviewed through the local government process. In addition, DEQ can provide assistance to state or federal agencies in advance of their submission for a consistency review.