OVERVIEW OF INTERNET BASED GIS AND HOW GIS AND CREATION OF A TAX PARCEL LAYER RELATE TO CURRENT COUNTY PROJECTS
Internet based GIS enables users to view graphical information and associated data over the internet.
Nelson County is currently positioned to be able to serve an internet based GIS product that would show roads, structures, addresses, election districts, school districts, orthophotography and various other layers likely of lesser interest.
Typically, an internet GIS product becomes of great value to citizens, businesses and staff when a parcel layer is included and linked to the county’s real estate database. This provides users with the ability to query the map based on information contained in the database; for example, one can use the product to determine the parcel where a particular house is located, the address of a structure on a particular parcel or to display information contained in the property record maintained by the Commissioner of Revenue. This functionality is of great benefit to a range of businesses whose work depends on access to parcel data. The availability of this information online will greatly reduce the dependence on county staff to provide such information and the amount of time that county staff spends on providing this service.
Providing staff with access to GIS data via the web reduces GIS expense overall for the county since staff can access the data without the expense of installing costly software on computers. Only those users requiring data creation functionality would be required to invest in costly software. Varying degrees of capability can be built into the web based product to meet the needs of staff and the public.
Many counties currently serve a web based GIS product to their citizens and staff. The following counties are currently serving GIS via the web: Bedford, Botetourt, Floyd, Fluvanna, Giles, Greene, Henry, King George, Louisa, Montgomery, Orange, Patrick, Pulaski, Rockbridge, Smyth, Southampton, Washington, Westmoreland and Wise. Many other counties also off this service however, this list only includes counties using MSAG or Anderson and Associates to host their site.
Fees for the service depend largely on the number of layers that the county opts to display in the system.
The E-911 Program is working to select a mapping system to provide digital mapping essential to the effective handling of wireless 911 calls. The State Wireless Board recognizes the importance of mapping to E-911 and has agreed to fund 100% of the cost for the purchase and implementation of a mapping system to support wireless and wireline 911. At this time, it is expected that the county will spend approximately $100,000 for this mapping system. Additionally, the state has spent millions of dollars for the creation of statewide digital orthophotography that will be provided to the localities at no charge. Nelson County is scheduled to receive this product within the next week.
Considering these two projects, now is the perfect time for the county to continue with its progress in GIS. The products funded by the state provide the county will a springboard into GIS and serve to greatly reduce the cost burden to the county.
The most important step in building a GIS involves the creation of a digital tax parcel layer. This step is essential before GIS can be used as an analysis tool in the county. A digital tax parcel layer can be included in the same system used to create and maintain addressing and mapping thus serving a number of users. Use of the orthophotography product will not only allow layers to be viewed with a photo backdrop, but will also provide the means by which the tax parcels can be properly rectified to fit the county’s base map. Natural boundaries visible on the orthophotos will be used to ensure that parcel boundaries fit the orthophotos and in turn other mapping layers.
Once the tax parcel layer has been created, tax maps can be maintained either in-house or continue to be contracted out.
Digitizing tax parcels now would also serve to provide the basis for the creation of a new zoning map required by the new zoning ordinance. The zoning map should show what parcels are included in any given zone. Digital data for both the zoning map and the tax maps will result in the most effective creation, interpretation and maintenance of the maps. Once the county has the tax maps in digital form, it is possible that the zoning map could be created and maintained in-house.
The following options would be available for accomplishing the parcel mapping:
There is much to consider in properly planning and building a GIS system that will meet the needs of all county departments. It is important to formulate a plan that ensures that each component work with and complement the others. I cannot stress enough the importance of creating data tailored to a single base map rather than independently creating data and later attempting to combine and retrofit products.
(NOTE: Document author – Susan Rorrer, E-911 Coordinator. Presentation at the April 2 Board of Supervisors’ Budget Session)