Local government users of GIS technology are beginning to explore how to best implement Esri's new geodatabase architecture for geospatial data management. This presentation will discuss the creation of a water/wastewater facility GIS database for a municipal government using the ArcFM Water model. The presentation will review issues that need to be addressed when creating facility GIS data for the first time or converting existing data from ArcInfo coverages/shapefiles into the geodatabase structure. A decision making process for ArcFM Water database modeling and sample model modifications will be covered. In addition, overall technical, organizational and workflow requirements will be discussed.
In addressing an implementation of the ArcFM Water data model, GeoAnalytics has generated a typical scenario from which to begin describing a hypothetical installation employing the ArcFM Water data model and ArcGIS technology.
A typical user or implementer of the ArcFM Water data model is a sewer or water utility from a local unit of government. They have paper-based systems at this point in time with some level of automation and modernization of utility data. In a best-case scenario, the utility will have facilities stored in discrete CAD layers or as simple features in a GIS. Attributes are stored as paper files or spreadsheet depictions of the system. Often GIS is a more mature technology in other parts of the local government organization and the utility wants to use ‘best of breed’ technology to automate their systems.
It would be common for the utility to be aware of GASB34 financial reporting requirements. The utility should be proactive and get ready for the change. Additionally, the utility knows that their system could be more efficient which usually means that the technology currently being used has to be supplanted.
The typical situation has users who want to maintain the system through a mapped-based graphical interface. "Dumb" data layers are no longer sufficient to support utility business functions with new data requirements to include the necessity for “smart data”, where features are linked via relationships.
Users will require the ability to perform robust queries and analysis of their data and demand high data integrity to ensure the quality of the system. Attributes are to be incorporated as a part of the system and not managed via other interfaces or maintained in other databases, but in the corporate database.
The system to be developed must handle on-line decision support, as well as, increased demand for distribution of data and a seamless view of the sewer & water systems.
A number of issues arise when moving data from legacy spatial datasets to a geodatabase of the ArcGIS Water data model. The most common issue will be the difference in the way data sets model flow. Depending on the source data, numerous ways of describing flow can be used. The preferred method in the ArcFM water geodatabase is the use of sources and sinks; discrete features, that in effect, describe the high and low points of the network. It is necessary to have this data identified and available during data loading to facilitate the process. Network flow can be deduced programmatically from the underlying features, but this requires regular rerunning of application code after edits are applied to regenerate flow.
From a tabular perspective, determining the content of the database is a major effort. Because the model is a “straw man” of average content across numerous systems and uses, the content must be reviewed for adherence and deviation from the model. Where differences are identified, they need to be documented and incorporated.
The ArcFM Water Logical Analysis model is an excellent tool for beginning the identification of differences between a user’s system and the standard ArcFM water model.
Depending on the type of model modification identified, this will determine where changes to the model can or must be made. Simply put, the more foundational the change, the more likely the change will occur in a CASE tool environment against a UML model of the ArcFM Water data model.
GeoAnalytics believes the ArcFM Water data model is a very useful tool that benefits the user community in several ways by:
Thanks to the cities of West Chicago, Illinois, and Waukesha, Wisconsin, for letting GeoAnalytics be a part of their system development. Thanks to Becky Cummings, GeoAnalytics, for all her hard work.
Aaron Cohen, Land Records Services Manager
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Madison, WI 53704