His experiences in Idaho made Anderson realize how underutilized GIS was for emergency preparedness in his own city. Up to that time, he had given little thought to Fremonts GIS unit in terms of developing emergency applications. "They do a variety of work, although not typically for emergency services," Anderson said. "We could have them producing maps ahead of time that would enable us to better respond to major disasters."
The first opportunity to use GIS in managing a potential crisis wasnt long in coming; in 2000, Fremont was hit with the first of several rolling blackouts, many of which came without warning. A city of nearly 100 square miles on the southeast side of San Francisco Bay, Fremont lies across major north-south highways running between San Jose and Oakland. Power outages at traffic signals along these arteries can result in accidents, pile ups and blocked emergency vehicles. Also at risk are critical facilities, including kidney dialysis centers, water district pumping stations, schools, office buildings with elevators, hazardous materials companies and pipelines transporting explosive liquids.
Since Pacific Gas & Electric schedules blackouts sequentially by circuit block, knowing the next block to go down and the section of the city it covered could enable Fremonts Emergency Operations Center (EOC) to move resources and personnel into the area ahead of time to direct traffic, put up stop signs and barriers and set up portable generators to power traffic lights at critical intersections. Knowing the next area to go down could also assist the EOC in establishing alternate routes for emergency vehicles, providing backup power for critical facilities and freeing people trapped in elevators.
To more accurately predict where the next blackouts were going to be, the EOC needed maps of the city sectioned by each PG&E circuit block. According to Anderson and other members of the EOC, however, PG&E declined to release specific circuit block information. "They cited reasons of national security for withholding the information," Anderson said. "I [could] cite some local security reasons why we should have the information. So [we were] at odds."
Building a Plan
Rather than give up, the EOC developed a plan to use the citys PG&E bills to determine which circuit block each traffic signal was in. "Since we couldnt get the block information directly from PG&E, we went through a back door I dont think many people are aware of -- every traffic light has an intersection location and a PG&E bill indicating the circuit block that light is in," said Christine Frost, Fremonts GIS manager.
After collecting and manually tabulating the data on intersections and traffic signals from PG&E bills, the EOC requested the GIS group translate the data into maps. The GIS group created a point file of traffic-signal intersections and their respective PG&E blocks, then loaded the data into ArcView. Using the signal locations as the foundation, the group developed rough outlines for each of the blocks overlaid on top of a base map of the city.
The EOC also provided the GIS group with a list of critical facilities and infrastructure likely to be affected during blackouts -- schools, hospitals, nursing homes, parks and dialysis treatment centers. Hazardous materials locations and pipelines will be added later.
In addition to providing paper maps requested by the EOC, Frost saw that an interactive map application could be included in Fremonts already extensive GIS database and made available via the citys fiber-optic intranet. Using Autodesks MapGuide, the GIS unit developed a Web-based application that could be viewed with a plug-in downloaded from the Internet.
"Within 24 hours we had the paper maps, and within 48, the Web application," Frost said. "Police, fire and maintenance can go to the MapGuide site, search and zoom in on a particular location and print the maps they need to have in the field. And they can do that on their own very quickly."
Being Prepared
Maintenance Director Jack Rogers explained that when Californias Independent System Operator announces a Stage 3 power alert, indicating the state is running extremely low on power reserves, the city gets ready for rotating blackouts. "When the alert comes in, we form the EOC group and develop response plans for the next two hours to 48 hours, depending on how long we think the blackouts are going to last," he said.
PG&E announces the order in which areas of the city will be hit with rolling blackouts. Using the maps, the EOC can immediately see if a major thoroughfare will be involved. If so, the city can direct additional police officers to the area. Maintenance workers can be sent to put up stop signs in major intersections or portable generators in areas with traffic signals that can be run by them.
"The big advantage of these maps is that they allow us to actually see which parts of the city were going to be affected," said Rogers.
Anderson said the maps enable the fire department to identify potential public safety issues and plan alternate response routes. "We can choose routes other than the main north/south thoroughfare, broadcast them to all of our stations, and have them respond accordingly. We can also click on the map, bring up critical facilities in the next block to go down and alert those people and ours so we can be better prepared," he said.
The maps also enable the fire departments hazardous materials team to locate and alert chemical companies. "If theyre mixing certain chemicals and the power goes down, leaving them unable to stabilize the process, the results can be a real issue for us." Anderson said. "But we can locate those companies now by PG&E block, so we can alert them and our HAZMAT team ahead of time to be prepared to handle problems."
Anderson said the EOC and the police department have had enough time with the maps to assess the intersections, determine the ones they need to cover and the number of officers it will take. When the department gets a Stage 3 alert, depending on the time of day and the next block or blocks to be hit, the department can hold a shift over and have extra staffing to cover intersections without jeopardizing public safety by tying up all the officers directing traffic.
Blackouts, however, do not always come with warning. At times the EOC receives no warning from PG&E; other times they will get 10 minutes, sometimes an hour. "The last one was four minutes," Anderson said, "but we had the maps and map data layers and a game plan, so we already knew how to identify key locations we needed to cover. It was just a matter of getting our resources out there."
Anderson said that even with brief warnings, the maps have enabled the EOC to be better prepared when blackouts occur. "When we know the last block that went down, we can determine what sections of our jurisdiction are going to be effected next and pre-stage equipment in those areas. The more we know ahead of time, the more effectively we will be able to manage the incident, whether it is a rolling blackout, earthquake or flood."
Ed. Note -- PG&E has now released circuit block information to Fremont and other cities.
