Introduction to the Boundary and Annexation Survey BAS

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Introduction to the Boundary and Annexation
Survey (BAS)

• South Carolina Arc Users Network Conference
• Bernadette Jenkinson
• U.S. Census Bureau
• January 22, 2007

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Presentation Overview

• Boundary and Annexation Survey (BAS)
• - What is the BAS?
• - Why do we conduct the BAS?
• - Who benefits from the BAS?
• - What are the current and future BAS submission
  methods?
• - What are important dates for the current BAS
  year?
• - Who should you contact if you have questions?

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What is the Boundary and Annexation Survey (BAS)?
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Boundary and Annexation Survey (BAS)

• Voluntary survey conducted annually to collect
  boundaries for legal areas
• Title 13, United States Code Census, Section 6
• gives the Census Bureau the authority to conduct
  the survey
• Office of Management and Budget (OMB)
• approves the materials for the survey
• Federal Register Notice
• public is notified of the survey and given the
  opportunity to comment

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Boundary and Annexation Survey (BAS)

• Primary source of information regarding
• legal boundaries
• names of governments
• legal status
• types of governmental units
• new government
• dissolved government
• boundary changes
• higher-level geographic relationships
• e.g. a place annexes into a new county or minor
  civil division (MCD)

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Boundary and Annexation Survey (BAS)

• Governmental units (entities) included in the
  survey
• counties and their equivalents
• MCDs
• incorporated places
• American Indian reservations and off-reservation
  trust lands (federally recognized)

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Why we conduct the Boundary and Annexation Survey
(BAS)?
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Boundary and Annexation Survey (BAS)

• Ensures that population and housing counts are
  assigned to the correct geography
• Used to present statistics for various censuses
  and surveys
• American Community Survey (ACS)
• Population Estimates Program
• 2010 Decennial Census Programs
• To support the Office of Management and Budget
  Circular No. A-16
• The Census Bureau is responsible for collecting
  and maintaining Legal Boundaries
• Geospatial One-Stop
• The National Map

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Who benefits from the Boundary and Annexation
Survey (BAS)?
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The Census Bureau

• Accurate, up-to-date boundaries result in
• a more accurate housing tabulation count for all
  our censuses and surveys
• more accurate statistical data
• a reliable geographic reference source

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But. Who Else Benefits?

• Redistricting officials in every state
• Participants in the Local Update of Census
  Addresses (LUCA)
• Other federal agencies

• States
• Counties
• Townships
• Cities

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State-Level BAS Agreements

• State participation improves the BAS process and
  reduces duplication of effort
• Some states have the authority to either monitor
  or maintain boundary information for all legal
  entities in the state. Where this exists
• Some states provide us a list (each November) of
  entities that have had annexations that year.
  The Census Bureau uses this list to determine
  which entities should get a BAS package.
• Other states provide legal updates and
  corrections via paper or digital file directly to
  us.
• Current state-level agreements
• Georgia, Kentucky, Michigan, Minnesota,
  Wisconsin, Alaska and the Commonwealth of Puerto
  Rico

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County-Level BAS Agreements

• Counties respond to the BAS for the entities
  within their jurisdiction.
• To consolidate the BAS responsibilities, county
  officials
• Reach agreement with entities to provide their
  BAS submission
• BAS packages only are mailed to the county BAS
  contact
• Places within the county no longer receive a
  separate BAS package
• Current county-level BAS agreements
• Delaware Co., OH, Frederick Co., MD, Wake Co.,
  NC, and Ada Co., ID

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How we conduct the Boundary and Annexation Survey
(BAS)
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Determining the BAS Contact

• Each year BAS materials are mailed to our BAS
  contacts
• How do we determine who the BAS contact is?
• We are instructed by a local official as to who
  should receive the BAS package
• A local government employee responds to the BAS
  multiple consecutive years, the Legal Areas team
  will make them the BAS contact.
• If we have not received a BAS response for
  several years, the Legal Areas team will attempt
  to establish a contact in either a planning or
  GIS department.
• State Data Center staff provide contact updates
  to the Census Bureau during the telephone
  follow-up phase of BAS.
• If there is no BAS contact and the Census Bureau
  is unable to establish a contact, the package
  will be mailed to the Highest Elected Official
  (HEO)

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• What are the current BAS submission methods?

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Current Submission Methods

• Traditional BAS
• E-BAS
• Digital BAS

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Traditional BAS

• Census Bureau
• mails paper maps and a BAS form to the BAS
  contact
• Participants
• annotate and return large scale paper maps and
  forms
• provide documentation for each legal boundary
  change (date, number, acreage)
• If the participant does not have any changes to
  report, they can return a No Change postcard

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E-BAS

• Participants
• are able to
• login to a secure website
• submit a No Change postcard or form updates.
• are not able to
• submit map updates
• The E-BAS website is linked off of the BAS
  homepage (http//www.census.gov/geo/www/bas/bashom
  e.html) and the username and password are
  provided in the Special Instructions section on
  the paper form.
• In 2008, E-BAS will be replaced with Web-BAS.

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Digital BAS

• First offered during the 2005 BAS for a limited
  number of entities
• Designed to accept submissions from experienced
  GIS users who modify Census Bureau spatial data
• Spatial data provided in shapefile format
• Goal is to permit governmental units to
• update digital files in place of paper maps
• submit boundary change information through
  digital file metadata
• Participants are required to
• follow the detailed requirements posted on the
  BAS website http//www.census.gov/geo/www/bas/ba
  shome.html
• Limited to entities and counties
• that have gone through the Census Bureaus MTAIP
  process

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Digital BAS
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Topological Relationships in TIGER

• TIGER is a topologically integrated file
• Instead of having a layer for each feature class
  all information is stored in one file
• One line in TIGER can represent multiple
  boundaries and features
• This ensures that the spatial relationships
  between different boundaries and features are
  maintained

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Topological Relationships
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Topological Relationships
Road
Block Boundary
Place Boundary
School District Boundary
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Topological Relationships
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Topological Relationships
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Challenges of Using Parcel Based Source Files
for Digital BAS

• Many localities develop their boundary file based
  on a parcel source file.
• Without specific guidance from BAS participants,
  the Census Bureau geocodes addresses and
  establishes population counts based on the
  relationship of an entitys boundary to the road
  centerlines.
• The Census Bureau has established geographic
  offsets and corridors to aid in the assignment of
  addresses to the correct geography.

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What is a Geographic Offset?

• An area claimed by an entity that is only on one
  side of the road and does not contain any
  structures addressed to that side of the road.
• The Census Bureau geocodes addresses based on the
  centerline of roads
• If your boundary is not coincident with the
  centerline but follows the parcel line, and the
  residential structures along the road should be
  in your jurisdiction, you need to report a
  geographic offset
• By coding the offset the residential structures
  will be assigned to the correct geography

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What is a Geographic Offset?
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What is a Geographic Offset?
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What is a Geographic Corridor?

• An area that only includes road right-of-way and
  does not contain any structures addressed to
  either side of the road.
• Once again The Census Bureau geocodes addressed
  based upon the centerline
• There are two types of geographic corridors
• An area where a road, or other feature is not
  incorporated by a place
• An area where a road, or other feature, is the
  only piece of incorporated place

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What is a Geographic Corridor?
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What is a Geographic Corridor?
By creating change polygons and coding them
appropriately in the table, the addresses are
moved from the place to unincorporated area.
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• What additional participation methods are in
  development?

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Future Submission Methods

• Web-BAS
• MAF/TIGER Partnership Software

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Web-BAS

• Available for 2008 BAS
• Participants will be able to
• login to a secure website
• submit a No Change postcard, map updates, and
  form updates
• Participants will receive a user name and
  password in January of each year.

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MAF/TIGER Partnership Software

• Available for 2008 BAS
• Participants will receive
• a CD containing the software to install on to
  their computer
• one or more CD(s) containing the data for their
  entity and the surrounding area
• a user name and password to access the data in
  the software
• Participants will be able to submit map and form
  updates.

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• What are important dates for the current BAS year?

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Current BAS Year Activities

• Important Dates
• Package Mailout
• January
• Digital Submission Notification
• Entities must indicate their interest in Digital
  BAS by February 15th
• Submissions Received by
• April 1, updates will be included in the
  population estimates program the following
  calendar year
• Digital Submissions Received by
• April 1st , updates will be processed for
  inclusion into the MAF/TIGER database

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Current BAS Year Activities

• Other Dates
• Prenotification
• September
• States Provide Universe list
• October-November
• State Data Center Follow-up
• March-May
• Traditional BAS Submissions
• Received By May 31
• updates will be included in the next BAS
  materials
• Received After May 31
• updates will be made after the next BAS mailing

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Future Goals

• Expand Digital BAS
• Partnership Agreements
• Increase the number of consolidated BAS partners
  at the county and/or state level
• Boundary Validation Program (BVP)
• After the 2010 BAS, the Census Bureau will send a
  Boundary Validation Map to the Highest Elected
  Official of every legal entity in the United
  States for final review before tabulation.

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• Who should you contact if you have questions?

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Census Bureau Contacts

• Sending your package
• US Census BureauPO Box 5000Jeffersonville, IN
  47199-5000
• Requesting additional or replacement materials
• Phone [phone]Email geo.bas_at_census.gov
• Requesting to participate in Digital BAS
• Phone [phone]Email geo.bas_at_census.gov