Geospatial Data Governance Policies and Procedures: A Guide (2025)
Chapter: Appendix D: GIS Data Maintenance Needs Estimates
APPENDIX D
GIS Data Maintenance Needs Estimates
Assumptions and Constraints
Several factors are involved in estimating how many person hours per year will be needed to maintain GIS data. However, rather than trying to estimate all the potential hours involved for all staff, this workload estimate will focus solely on the need for a technician with GIS data maintenance skills to maintain the GIS features and attributes, including all the requisite collaborator and technical coordination. Any resource needs to maintain CAD and BIM data or do data translations between GIS and these other formats would be in addition to these estimates for GIS data maintenance.
Annual Update of All Features
It is assumed that the FAA-required GIS data will be updated or validated at least annually. The annual updates will also include GIS data of interest to the airport not included in the FAA standards, and data required by the FAA that affect other departments’ assets at the airport (utilities and street transportation). These annual updates are anticipated to be needed because of at least one construction project per year, and the need for an annual data audit to verify any data that is no longer current. The hours required for the annual update are conservatively estimated.
Data Development Sources, Data Exchange, and Tracking Responsibilities
Source data is assumed to be prepared mostly by design consultants or surveyors, with additional feature or attribute data contributions from geospatial data producers. It is the responsibility of the geospatial data curator to also stay generally informed of activities at the airport that could affect the GIS data, evaluate the potential data change factors, and source data for potential impacts to the GIS data. Once an actual data change impact is identified (CIP, tenant project, or maintenance activity), the geospatial data producer is responsible for obtaining the proper data, conducting a technical evaluation on the source electronic files or other source data, and coordinating with the various collaborators on the data updates and acceptance into the central GIS data warehouse.
On a quarterly basis, it is anticipated that the geospatial data curator will interface with collaborators or other geospatial data curators to discuss upcoming data updates and status of ongoing data updates, map, and other electronic data requests. A recurring data exchange will occur to either obtain CAD/GIS data either useful for updating the airport’s geospatial data warehouse, or the geospatial data producer will provide appropriate airport geospatial data to design
consultants or other third parties for modification and later including back into the airport’s geospatial data warehouse.
Thematic Map Production
An element to the workload estimates that is built into this data maintenance estimate is the need for producing GIS thematic maps for collaborators and information sharing based on the geospatial data. Most collaborators and airport staff are consumers of geospatial data but are not producers of geospatial maps, nor do they possess the cartography skills necessary to create properly formulated cartographically correct and presentable map exhibits.
Some of the geospatial data sets will require only occasional, or a rare need for map creation. However, experience at other airports has shown that some geospatial thematic maps will become crucial management tools for disseminating information. Typically, “popular” geospatial maps that require regular updates at airports include monthly updates for recurring executive meetings or presentations depicting planned and actual construction improvements, existing and proposed obstacles and obstruction identification surfaces (OIS), location of work orders or issues of concern, spatial extents of leaseholds, etc.
The need for spatially correct map exhibits for presentations and FAA reporting, with no ability to freely access the geospatial data portal helps to further justify that geospatial data producer resource be allocated to serve the airport’s ongoing data maintenance/distribution needs.
GIS Layer Assumptions
The staff hour estimate was developed by taking the FAA-required GIS data layers expected to be produced as part of a typical airport GIS mapping effort for a medium-sized airport, and then adding in other common layers the FAA does not require.
Feature and Attribute Assumptions
The following factors were developed to provide some objective estimated effort for this analysis:
The frequency of annual updates for each layer assumed a minimum of one annual update.
Some geospatial data curator ownership was assumed. Most but not all layers were assumed to be the responsibility of the airport geospatial data curators and producers. Some data layers could be maintained by the utilities owner/department, the municipal street transportation department, or a local municipal planning organization (MPO).
Total staff hours required for each update included time spent to
- Coordinate with data collaborators, data users, and data producers;
- Obtain and evaluate source data;
- Modify geometric features and attributes;
- Provide data products; and
- Produce and distribute thematic maps.
These hourly estimates were based on the assumptions of
- At least one airside CIP construction project per year;
- Quarterly updates due to airside or landside maintenance activity;
- At least one landside construction project per year, on airport property;
- Production of at least one recurring thematic map each month, and a special custom map bimonthly; and
- Monthly interaction pertaining to the airport geospatial data.
Conclusion
These GIS data maintenance factors are summarized in Table D-1. The result of this analysis is an estimated need for three-quarters of an FTE to support the ongoing annual data distribution and GIS data maintenance needs of a medium airport. The geospatial data producer could be provided by the airport, airport consultants, or a combination of both.
Table D-1. Medium-sized airport annual estimated GIS maintenance effort.
| Data Group | GIS Layer: AC-18B and Other Common Layers | Total Annual Hours | Data Owner |
|---|---|---|---|
| Airfield | Air Operations Area | 9 | GIS |
| Airfield | Aircraft Non-Movement Area | 9 | GIS |
| Airfield | Airfield Design Area | 9 | GIS |
| Airfield | Airfield Design Line | 9 | GIS |
| Airfield | Airfield Light | 33 | GIS |
| Airfield | Airfield Sign | 33 | GIS |
| Airfield | Apron | 33 | GIS |
| Airfield | Blast Pad | 9 | GIS |
| Airfield | Displaced Threshold | 9 | GIS |
| Airfield | Frequency Area | 9 | GIS |
| Airfield | Helipad | 9 | GIS |
| Airfield | Marking Area | 66 | GIS |
| Airfield | Marking Line | 66 | GIS |
| Airfield | Runway Centerline | 9 | GIS |
| Airfield | Runway End | 9 | GIS |
| Airfield | Runway Label | 9 | GIS |
| Airfield | Runway Segment | 9 | GIS |
| Airfield | Shoulder | 34 | GIS |
| Airfield | Taxiway Holding Position | 17 | GIS |
| Airfield | Taxiway Segment | 33 | GIS |
| Airspace | Obstacle | 12 | GIS |
| Airspace | Obstruction Area | 5 | GIS |
| Airspace | Obstruction ID Surface | 5 | GIS |
| Airspace | Tower (Freestanding Towers, Not FAA ATCT) | 5 | GIS |
| Cadastral | Airport Land Use—Existing/Future | 18 | GIS |
| Cadastral | Airport Property Boundary | 12 | GIS |
| Cadastral | City Limit | 0 | Muni |
| Cadastral | Flood Zone | 0 | Muni |
| Cadastral | Lease Area | 112 | GIS |
| Environment | Contamination Area | 10 | GIS |
| Environment | Hazmat Storage Area | 6 | GIS |
| Environment | Noise Contour | 9 | GIS |
| Environment | Sample Collection Point | 4 | GIS |
| Environment | Vegetation Area | 6 | GIS |
| Geospatial | Cost Center Boundary | 36 | GIS |
| Geospatial | Elevation Contour | 12 | GIS |
| Geospatial | Spot Elevation | 12 | GIS |
| Geospatial | Control Point | 6 | GIS |
| Geospatial | Image Area | 6 | GIS |
| Data Group | GIS Layer: AC-18B and Other Common Layers | Total Annual Hours | Data Owner |
|---|---|---|---|
| Manmade Structures | Building | 25 | GIS |
| Manmade Structures | Construction Area | 9 | GIS |
| Manmade Structures | Fence | 9 | GIS |
| Manmade Structures | Gate | 9 | GIS |
| Manmade Structures | Landside Sign | 36 | GIS |
| Manmade Structures | Passenger Loading Bridge | 3 | GIS |
| Manmade Structures | Tunnel | 3 | GIS |
| NAVAID | NAVAID Critical Area | 5 | GIS |
| NAVAID | NAVAID Equipment | 5 | GIS |
| Security | Restricted Access Boundary | 17 | GIS |
| Security | SIDA Boundary | 17 | GIS |
| Security | Sterile Area | 17 | GIS |
| Surface Transportation | Parking Lot | 20 | GIS |
| Surface Transportation | Road Centerline | 0 | Muni |
| Surface Transportation | Sidewalk | 20 | GIS |
| Utilities | Backflow Preventer | 17 | Util |
| Utilities | Cleanout | 17 | Util |
| Utilities | Electric Generator | 17 | Util |
| Utilities | Electric Light Pole | 17 | Util |
| Utilities | Electric Meter | 17 | Util |
| Utilities | Electric Power Distribution Panel | 17 | Util |
| Utilities | Electric Transformer | 17 | Util |
| Utilities | Floor Drain | 17 | GIS |
| Utilities | Fuel Drain or Vent | 17 | GIS |
| Utilities | Fuel Pipe | 17 | GIS |
| Utilities | Fuel Pit | 17 | GIS |
| Utilities | Fuel Pump | 17 | GIS |
| Utilities | Fuel Station | 17 | GIS |
| Utilities | Fuel Storage Terminal | 17 | GIS |
| Utilities | Fuel Valve | 17 | GIS |
| Utilities | Gas Distribution Main | 17 | GIS |
| Utilities | Gas Emergency Isolation System | 17 | GIS |
| Utilities | Gas Meter Set Assembly | 17 | GIS |
| Utilities | Gas Service Line | 17 | GIS |
| Utilities | Gas Transmission Main | 17 | GIS |
| Utilities | Gas Valve | 17 | GIS |
| Utilities | Grease Traps | 17 | GIS |
| Utilities | HVAC General Equipment | 17 | GIS |
| Utilities | Roof Drain | 17 | Util |
| Utilities | Sewer Cleanout | 0 | Util |
| Utilities | Sewer Junctions | 0 | Util |
| Utilities | Sewer Fitting | 0 | Util |
| Utilities | Sewer Lift Station | 0 | Util |
| Utilities | Sewer Main | 0 | Util |
| Utilities | Sewer Manhole | 0 | Util |
| Utilities | Sewer Meter | 0 | Util |
| Utilities | Sewer System Valve | 0 | Util |
| Utilities | Sewer Taps | 0 | Util |
| Utilities | Storage Tank | 0 | Util |
| Utilities | Storm Conduit Closed | 17 | GIS |
| Utilities | Storm Conduit Open | 17 | GIS |
| Utilities | Storm Fitting | 17 | GIS |
| Utilities | Storm Flow Divider | 17 | GIS |
| Utilities | Storm Inlet | 17 | GIS |
| Data Group | GIS Layer: AC-18B and Other Common Layers | Total Annual Hours | Data Owner |
|---|---|---|---|
| Utilities | Storm Manhole | 17 | GIS |
| Utilities | Storm Oil Water Separator | 17 | GIS |
| Utilities | Storm Outfall | 17 | GIS |
| Utilities | Storm Pump | 17 | GIS |
| Utilities | Storm Retention Basin | 17 | GIS |
| Utilities | Storm Storage Unit | 17 | GIS |
| Utilities | Storm Structure Outlet | 17 | GIS |
| Utilities | Storm Sub Catchment | 17 | GIS |
| Utilities | Storm Weir | 17 | GIS |
| Utilities | Water Backflow Preventer | 0 | Util |
| Utilities | Water Booster Station | 0 | Util |
| Utilities | Water Flow Meter | 0 | Util |
| Utilities | Water Hydrant | 0 | Util |
| Utilities | Water Hydraulic Control Valve | 0 | Util |
| Utilities | Water Interconnect Line | 0 | Util |
| Utilities | Water Interconnect Point | 0 | Util |
| Utilities | Water Main | 0 | Util |
| Utilities | Water Production Well | 0 | Util |
| Utilities | Water Recharge Well | 0 | Util |
| Utilities | Water Storage Basin | 0 | Util |
| Utilities | Water System Valve | 0 | Util |
| Utilities | Water Taps | 0 | Util |
| Utilities | Water Volume Meter | 0 | Util |
| Total Annual GIS Data Maintenance Hours | 1540 |
NOTE: ATCT = air traffic control tower; HVAC = heating, ventilation, and air conditioning; NAVAID = navigational aid; and SIDA = security identification display area.
