How many fire hydrants are there in Bradley County?
How far does a driveway extend?
These and other geographic questions about Bradley County can be answered by the Geographic Information Systems department.
The department works to provides maps with different layers of information to many county departments.
“Probably the main function is … to manage GIS data, so that they can use it to make maps,” GIS director Wayne Owenby said. “If you don’t have someone to coordinate it, everyone has their own way of doing it, and it doesn’t go together.”
Owenby said GIS is a good tool to give a good overall view of county data.
The department has layers that give data for everything from the location of houses and streets to trees and stop signs.
This information is laid on top of an image similar to a highly detailed satellite image. The image is constructed from photos taken from a plane flying at about 5,000 feet.
The county contracts an independent company for this service.
“They fly north to south back and forth, and take thousands and thousands and thousands of images and they’ll put it together in our structure and it usually takes about four or five months,” Owenby said.
A new image is acquired every four years. Owenby said the most recent image is from 2012. He said a number of swimming pools were added to his information as a result of the image.
The aerial photographs limit the amount of structures that have to be manually input into the system. Owenby said when a new structure is built he will go to the site with a portable GPS unit that allows him to determine the exact location and coordinates of property lines to be put into the system.
“By having those points I can go in and draw the parcel lines,” Owenby said.
Many times property line information is given to the GIS department by the assessor’s office.
Owenby said he is constantly updating the map image to include things that are missing from it, such as a new driveway.
“It’s basically just collecting data all day,” Owenby said. “The data never stops. It is always changing.”
Each line drawn on the GIS map has data attached to it. It is this data that allows Owenby to have different layers of information showing at one time.
Other data the department receives is topographical information that gives depth to the images.
Recently, Owenby worked closely with Bradley County Fire-Rescue to map out how many structures would be covered for different proposed locations of the new fire stations being built.
The Bradley County Fire board looked at the maps with the fire chief to determine the best location for the stations.
Bradley County GIS programs measures miles based on the centerlines of the road.
BCFR was interested in how many structures were within a 5-mile radius.
“It’s pretty accurate. The only difference would be, this goes on the centerline of the road, you drive on the right side of the road, so if you’re driving on the inside it might be a little shorter. If you are driving on the outside of a turn it might be a little bit further than five miles, but it gives you a general start,” Owenby said.
The GIS department also worked with the Bradley County 911 Center to develop information for 911 dispatchers. The information gives the dispatchers information on what is the closest fire station to each major intersection in Bradley County.
In preparation for an inspection of the fire department for insurance ratings purposes, Owenby anticipates he will be spending time adding fire hydrants to his maps.
GIS information is also used by the Bradley County Commission during redistricting years to determine where district lines can be redrawn to meet state requirements. Owenby said some commissioners came to him last time and asked him to map out different options through his programs.
“It was just so simple because the software did everything for you,” Owenby said. State requirements dictate the number of residents who need to be in each district. District lines are redrawn every 10 years.
Owenby’s department uses the latest U.S. census to estimate how many people live in each area.
The GIS department also works with the engineering department to map out and collect data on culverts.
Owenby’s experience with maps began while he was working in the office of the Bradley County assessor of property.
The more map work the county needed, the more GIS work needed to be done. The department was created in 1999. Owenby applied and was chosen for the position, which he has filled ever since.
A GIS committee is a part of joint ventures where the county and city GIS departments need to work together.
A major joint venture is acquiring the new, big picture image every four years.
Owenby said the committee bids the project, chooses the company to complete the project and determines how it will be funded.