The Boundary and Annexation Survey (BAS) is an annual program conducted by the U.S. Census Bureau. Its primary purpose is to collect and maintain up-to-date information on the legal boundaries and names of various governmental and administrative areas across the United States.
Here's a breakdown of what the BAS entails and its importance:
What is it?
| • | Annual Survey: The Census Bureau sends out the BAS each year to tribal, state, and local governments. |
| • | Boundary Updates: Governments review the Census Bureau's data on their legal boundaries and report any changes, such as annexations, disincorporations, or name changes. |
| • | Geographic Areas: The survey covers a wide range of legally defined areas, including: |
| o | Counties (and equivalents like parishes or boroughs) |
| o | Incorporated places (cities, towns, villages) |
| o | Minor Civil Divisions (MCDs), such as townships |
| o | Federally recognized American Indian and Alaska Native areas |
Why is it important?
| • | Accurate Population Data: The boundary information collected through the BAS is crucial for the Census Bureau to accurately tabulate data for its various programs, including the decennial census, the American Community Survey (ACS), and the Population Estimates Program (PEP). |
| • | Federal Funding: Accurate population counts, which are directly tied to these boundaries, are used to determine the allocation of hundreds of billions of dollars in federal funds for programs and services like education, housing, healthcare, and transportation. |
| • | Informed Decision-Making: Local governments and other organizations use this data for their own planning and decision-making processes. |
| • | Maintains Geographic Databases: The updates provided through the BAS are integrated into the Census Bureau's geographic database, known as the Master Address File/Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) System, which is a foundational dataset for many other federal and public agencies. |
How does it work?
| • | Survey Package: Each year, an official in each eligible government receives a BAS package, which typically includes an introductory letter, survey forms, and maps showing the current boundaries of their jurisdiction. |
| • | Submission Methods: Governments can respond to the survey using various methods, including: |
| o | Geographic Information Systems (GIS) software |
| o | A web-based application provided by the Census Bureau |
| • | Verification: The Census Bureau reviews and verifies all submitted updates to ensure they are consistent with state laws and other documentation. In cases of boundary disputes, the Census Bureau will not make changes until the parties reach a written agreement or a final court decision is made. |
Boundary and Annexation Files
