Adams County GIS

Geographic Information System

101 N 54th St

Quincy, IL 62305

217-223-0614

Download Adams County GIS Brochure in PDF (4.62 MB)

Adams County is located on the Mississippi River in West Central Illinois. It encompasses 869 square miles with a population of 66,090. The total city and village population is 46,286 including the largest city, Quincy, which has a population of 42,202. The County is largely an agricultural based community with several major industries and retail areas within and near the city of Quincy. There are approximately 36,000 parcels within the boundaries of the County.

Several years ago, the County realized there was a need to develop a quality spatial data base for use by the community and private enterprise. It is estimated that as much as 80% of local government information has a geographic component (e.g. address, subdivision lot, ward and precinct, census tract, northeast quarter section 1, etc.) It was decided to use a Geographic Information System (GIS) in order to organize the variety of information available to the County. This system allows the user to analyze the information based on a geographic location.

The Adams County GIS is a 10-year, multiparticipant-funded effort that began in 1992 and is now fully operational. Funding has been provided by Adams County, the City of Quincy and the five major principal utilities operating within the County (AmerenCIPS, Adams Telephone Cooperative, AT&T Cablevision, Adams Electric Cooperative and Ameritech). Other Participants include the Great River Economic Development Foundation, and the Chamber of Commerce. There has also been funding from Federal, State and private sector sources. Cooperation has been the focal point of this GIS, with assistance received by the Tri Township Fire Department, Road District commissioners and Two Rivers Regional Planning Council.

There are two Engineering firms assisting the Adams County GIS. These firms are Poepping, Stone Bach and Associates and Klingner and Associates, both of Quincy, IL.

The Adams County GIS is set up as a committee with voting members from the County, City of Quincy and other participants. Due to State laws, all contracts are executed through the County, which is the lead agency.

The County started this project with a needs assessment. This needs study found there was unnecessary map duplication and a lack of coordinated updates. There was also a lack of up to date mapping and standards along with an absence of comprehensive tax maps. Thus emerged the Adams County GIS 2002.

The County decided to use a one square mile pilot area to begin the GIS. This area was comparable to the entire County. It included State, County and Township roads, residential and industrial areas and floodplain/bottomland as well as bluff ground. The area was also served by most of the GIS participants.

It was decided that there are 8 basic layers common to the GIS participants. The Adams County GIS will maintain these layers: Zoning and Jurisdictional Limits; Addresses; Parcels; Street Centerlines; planimetric; Soils maps; PLSS/Subdivisions and monumentation and the digital Orthophotography. Other participants may add any information they choose to the GIS.

Participants are using this in engineering applications, site design, road construction and maintenance, and inventories (signs, culverts, structures, trees, etc.) to name a few applications.

The City of Quincy has an inventory of all utilities including fire hydrants, sewer and water, street lights, etc. They use the GIS for pavement management and site design. The GIS is also used for zoning determinations. The County has an inventory of all structures in the floodplain. The GIS has become an invaluable tool for floodplain management. They also have inventoried the signs, culverts and accident data. The GIS is used for economic development as well as road maintenance and inventory. The States Attorney also uses the GIS for Court Cases. These are just a few examples of data currently in use with the GIS.

One focus of the GiS at this time is the 911 addressing. The county did not have comprehensive addressing. Most rural addresses were a rural route box number. The County is currently completing addressing for the entire county, assigning a four digit permanent street number to all structures.

The Adams County GIS consists of a digital map based on the USGS digital data, Department of Interior Aerial Photography and US Census TIGER maps. These base maps have been edited and corrected with current street names and corporate limits. Address ranges have been completed for the entire County as a part of the enhanced 911 Rural Addressing Project.

The County has received the Digital Orthophotography, which is a part of the County's Soil Survey Update. These maps serve as a 1"=1000' base map for the rural portion of the County. Higher resolution of 1"=100' images are available for the City of Quincy and the 1 ½ mile jurisdictional limits of the city. The digital soils maps, including soil types are also available.

The orthophoto may be used as a back drop and the other layers (roads, hydrology, public land survey, etc.) may be digitally overlaid on the photo. The user may interchange (i.e. turn on or off) as the need warrants. The user may only want to see the roads and parcels or may only want the hydrology.

A large number of spatial databases have been and will be developed for the Adams County GIS project. In addition to the above-mentioned data, the County has purchased the USGS's new Digital Raster Graphics (DRG) files for all 22 quad sheets covering the County.

The County the FEMA Q3 flood zone maps and the Department of Natural Resources (DNR) CD's for use with the GIS project. The DNR CD's give information such as wells, mines, geology, wetlands and natural areas. There will also be data available from the US Army Corps of Engineers pertaining to levees, rivers and streams.

Other data gathered and used with the GIS includes utilities, survey control points and planimetric features, such as building footprints.

All information entered into the GIS is associated with a database. A simple click on a feature gives the user a photo of buildings on a site and the database information associated with the point or feature. The system will also analyze the information contained in the database. The user will be able to retrieve tax information, addresses and demographic data for the entire County.

One of the largest and most costly projects the County recently developed is parcel mapping. Adams County was one of the few remaining counties that did not have comprehensive parcel maps. This information is used with the new Soil Survey Update and accompanying digital soils maps and orthophotography information to provide a more fair and equitable means of farmland assessment.

Adams County feels the GIS 2002 project is one way to provide the quality information base needed to maintain Quincy and Adams County as one of the more progressive communities in the State.

This project has received the Special Achievement Award from the Consulting Engineers Council of Illinois and the Outstanding Civil Engineering Achievement Award from the American Society of Civil Engineers. The County also received the Excellence in Floodplain Management Award from the Illinois Association of Stormwater and Floodplain Management. The County was awarded the Service Award for Innovation & Leadership in GIS Implementation.

The multiparticipant nature of the project enabled the County to receive three National Spatial Data Infrastructure (NSDI) grants from the Federal Geographic Data Committee (FGDC). Due to its national exposure, the Adams County GIS is serving as a model for cooperative development and cost sharing of GIS Systems as well as a model for building GIS systems for rural and mid sized communities throughout the United States.