The Challenge
Berea, a local sewer authority in South Carolina, wanted to be able to spatially locate their sewer network data and keep better tabular records on their work activities associated with the network. When GIS was introduced into their organization in 1997, it promised several benefits. The results, however, were that it could only be used by a limited number of people due to the technical skills needed. Also, at the time GIS was introduced there was no reasonably accurate reference data available, such as road edge of pavements or parcels. Access to good basemap reference data was important for a number of reasons, but probably most important is the positioning of the system in the real world.
Transferring the sewer system from paper to digital required either surveying the entire system, which can be a very expensive, or visually placing the system in relationship to some other digital reference. The only feasible reference source available at that time was the paper county tax maps. These maps were scanned, matched, and entered into the computer system as the base reference system. The positional accuracy of the sewer system was totally dependent upon the accuracy of the parcel base utilized. Recently the County performed a complete update to the there GIS data and thereby improving the positional accuracy of layers such as road centerlines, edge of pavement, and parcels.
The new and improved county GIS data has revealed the positional errors of the old parcel basemap, rendering Berea's sewer inventory positionally incompatible. The on-going expense of maintaining the old parcel reference basemap plus the inability to utilize additional GIS layers created by the county such as elevation contours, building footprints and connecting regional sewer trunk lines helped to justify the conversion upgrade.
The Solution
Significant changes in the GIS software environments and Geodatabase modeling are producing good, practical solutions to help make GIS more useful. By using the power of the Geodatabase we were able to model their information with much more built in intelligence and by doing so improve the overall accuracy of the data into the future. The key was to first develop a model that meets national standards. The Berea sewer network was first adjusted at minimal expense to fit the new county reference basemap by utilizing some of the advanced data adjustment tools available in the new ArcGIS 8.2 software. Managing and editing the GIS data as changes are needed has always posed a problem. Making changes and edits is significantly complicated and requires a knowledgeable staff skilled with the editing software tools. In order to assist Berea, ARCADIS is managing the edits for their GIS data as an on-going service. As new sewer lines are constructed, the digital CAD files are sent to our GIS technician to include the new data in their sewer network. On a routine basis, new basemap data (property lines, ownerships, roads, etc.) are received from the County and updated in Berea's ArcReader map document. Also, any updates to the Western Carolina Regional Sewer Authority (WCRSA) trunk lines are updated and included. Berea's GIS sewer network data is physically connected to the WCRSA trunk data within their project. This is possible since countywide sewer geodatabase modeling standards were established by ARACDIS and the City of Greenville. On average, an updated ArcReader document is delivered monthly.
One new product is the free ArcGIS viewer ArcReader. ArcReader is to the GIS world as Adobe Acrobat Reader is to the publishing world. A benefit of utilizing ArcReader software is the ability for Berea to begin to distribute access to their sewer data to other parts of their organization without the expense of adding more software licenses or high-powered computer systems.
The next step for Berea is to begin to field collecting inspection data in a database/spreadsheet format so it can be linked directly to the corresponding pipes and manholes. This will allow us to cost effectively incorporate additional data into their ArcGIS project overtime and opens up the ability to use the system for more advanced functions, such as capacity modeling and regulation compliance.
As a result of utilizing the latest GIS technology improvements, we are able to help our clients improve their overall information management. We are providing total business solutions from the initial sewer design work to updating and managing GIS data and providing on-going technical support and assistance. This is helping to advance the growth and acceptance of the technology within the Berea Public Service District. GIS has moved from a high-overhead technology to a day-to-day information tool that helps them provide a better level of service to their customers.
