Creating a GIS without the budget for one
Thornton, Colo., has a recipe for achieving tremendous benefits from GIS, without having a line-item GIS budget. The magic ingredient in the recipe is Thornton’s finding and buying existing information. The spice is finding existing aerial photography and converting it to digital imagery for a fraction of the cost of digital orthophotos.
Increased economic development, better planning, reduced labor costs, exporting headcount from formerly stressed departments, improved public safety — all without a line item for GIS — may seem like alchemy, but this fast growing suburb of 65,000 has pioneered a technique that can be copied by others.
Thornton, the fastest growing municipality in the Denver area and one known for strength in water management, wanted to make sure it had the water supply to support future growth.
In 1991, Thornton was like most other cities. Maps were handdrawn, presentations involved copying, splicing, protractors and hand typed labels. The city’s planning division was severely backlogged, with the added burden of multiple meetings per month.
Additionally, in 1992, Colorado passed Amendment 1, a tax limitation law, which forced state, city and county governments to provide better service while cutting all budgets.
Thornton’s recipe for GIS leadership in this environment started with, “Getting it in and showing a quick turnaround,” according to Audrey Maydew, programmer analyst who acts as the city’s GIS coordinator.
The program includes a liberal amount of GIS championing, mixed with central GIS data storage and administration. Added to this is ii requirement that each city department participate in the direction of the GIS, know how to use it and take responsibility for maintaining its own data layers.
Finding aerial imagery, base and additional layers already created for others was critical to Thornton’s being able to show a quick turnaround from GIS. “Seeing information pictorially is extremely helpful for the non-GIS professional,” says Maydew, who realizes that with an organization-wide implementation, a number of non-GIS professionals must be able to use the GIS. In addition, applications such as economic development and community development presentations, park pavilion registrations and crime scene mapping could not be accomplish without aerial images.
Three times, Thornton went to RFP for the addition of a digital orthorectified layer of raster images. But the best proposal in the last round was $180,000, and when a GIS is being implemented without a budget, $180,000 is far too expensive.
Consequently, the city contacted Image Scans, Denver, to secure the needed images from two different overflights of areas immediately south and north of Thornton. The company then digitally corrected the difference in the scales of the two sources of film so that the appearance was identical.
The images are being rectified by Thornton using Redlands, Calif.-based ESRI’s GRID software to existing vectors in the outside purchased data. Thornton is finding the resulting five-foot accuracy sufficient to most tasks, and the visual information for applications such as crime scenes is readily available.
Using existing images and simple rather than full orthorectification, the city was able to reduce the cost of the raster layer by a significant amount. Since Thornton is much larger now than it was the first time existing images were purchased, this reduction in cost is allowing Thornton to purchase newer imagery more frequently.
Thornton purchased its base layer, consisting of rights of way and easements, from the local gas and electric utility, Public Service Company of Colorado.
The city is updated regularly on parcel ownership by the Property Data Center and title insurance companies.
Additionally, developers are required to submit ARC/INFO compatible files on proposals. An outside consultant, Berger and Associates, and the GIS technician provide both custom programming and GIS administration for departments too small to have an internal GIS resource.
