Keep your eye on the big picture. That's the advice Fontana, Calif., GIS Administrator Joseph Field offers for GIS application development and data management.

“You need to consider how“ even a small project can impact the whole enterprise,” he says.

The city invested in GIS in 2002 to manage its largest and most valuable asset—the sewer system—and since then, the Public Works Department has deployed GIS-based applications to better manage infrastructure and satisfy federal requirements. To facilitate data sharing citywide, all assets, address points, and parcels are given a unique identification number in the city's geodatabase. This makes it easier for one city department to integrate another's data into a GIS application or project for the city of 190,000.

“I can manage my own data in the yard and not worry about what anyone else is doing,” explains Rogelio Matta, senior administrative analyst for public works. “But when we want to link sewer billing data to our sewer lateral line data, the capability is there because we have connectivity through a parcel I.D.”

To do this, all city departments ensure key data components are verified and entered correctly in GIS. For example, being able to track pavement conditions is more important to public works than having accurate address data. But public works collects address data in the field so, for instance, the police department can use public works' street center-line data in its dispatching system.

“The idea is to make sure you think about the whole picture, because the data you're using will eventually be useful to another part of the organization,” Field says.

LOCATING LOST REVENUE

Public works uses GIS to view maps and maintenance history of the sewer network, determine pipes that need to be repaired or replaced, and assess the progress of work orders. Employees click on a section of pipe to see video and photos of the inside of 375 miles of main lines.

More importantly for Matta, if he wants to verify the sewer connections and confirm that the city is collecting sewer service charges for each connection, he links the lateral connections in his department's sewer system geodatabase with the Management Services Department's utility billing database.

City staff recently built the utility billing database using the unique I.D. for each address and parcel. Since the sewer system geodatabase associates lateral connections to the same unique parcel I.D. numbers, the two databases are linked with the unique I.D. of the parcels serving as the common thread. For parcels with multiple addresses and sewer connections, the unique I.D.s of the address point are used. The city uses ESRI's ArcSDE technology to store data, ArcGIS Desktop to analyze the data, and ArcGIS Server to deliver applications online.

“We're taking two separate systems that have no reason to be linked, and linking them to make some determinations,” says Matta. “We're identifying residents who are connected to the sewer line but for some reason aren't being billed. Because of the integration of the geodatabase with the sewer billing system, we can verify that we are in fact collecting the appropriate rate for a home—something we were unable to do before.”