City of Grantville - GIS Inventory

EPG worked with the City of Grantville on a Utility Asset Inventory to value infrastructure within the City. The asset inventory included the GIS mapping and valuation of systems within the City based on the date of construction, existing condition, and maintenance. This information was used as a means to estimate depreciation in compliance with GASB 34.

The following systems were evaluated and inventoried as part of this process; gas, electric, water, sanitary sewer, stormwater, and roads. EPG developed an approach for mapping these systems that used a combination of desktop digitizing and field verification using GPS.

As part of the desktop effort, EPG worked with the City to obtain final as-built drawings of newer subdivisions and developments in the City. These drawings along with historical maps of the older sections of the City were geo-referenced and used to locate as many system features as possible.

Following completion of the desktop digitizing, EPG field verified the location system features using a Trimble GeoXH GPS unit. The result was a GIS database made up of points (manholes, fire hydrants, valves, etc.) and lines (pipes, power lines, etc.) for each system mapped. In addition to identifying the geographic location, tabular information was also recorded and associated with each unique feature.      

EPG used aerial photography to create a spatially accurate street centerline file. This file includes attributes such as road name, width, surface type, address ranges, alias names, etc. Based on the road widths, EPG was able to calculate the total area of pavement within the City, which is a critical element in determining the value of this particular asset.      

The final result of this effort was a GIS database that included detailed information about all infrastructure in the City. In addition to being able to determine the value of these components, the City can also utilize this data to anticipate Capital maintenance needs and prioritize future projects.