Using GIS and GPS to Produce Maps of Rural Water System Features

Department superintendents are responsible for routing crews to multiple problems simultaneously. If crew members do not know the exact location of underground lines, locating lines and determining connections will take longer. This means customers may be without water longer, more water will pour onto the ground and be wasted, and additional expense will be incurred by the water department, which ultimately results in higher rates for customers.

Generally, rural water departments contract with engineering companies to install large lines (i.e., pipes with diameters of six inches or more). These lines are mapped, and updated copies of these maps are distributed to water departments periodically. However, maps are incomplete because smaller lines are not included in map updates.

That is where the West Alabama Regional Commission (WARC) comes into the picture. WARC was recently awarded a grant by the Appalachian Regional Commission (ARC) to compile detailed maps of all features in select rural water systems in western Alabama using GPS and GIS. Fourteen water systems in Bibb, Pickens, and Hale counties were involved in the project. According to ARC, these three counties are the most economically distressed in the western Alabama region.

Initial Preparations

After funding for the project was assured, WARC staff immediately began researching GPS software and receivers and the software and programs needed to convert the data into shapefiles for use in ArcGIS. Three Trimble GeoXT handheld GPS units, able to access as many as 12 separate satellite signals (under ideal conditions) and collect data with sub-meter accuracy, were ordered. TerraSync software, loaded onto the Trimble units, was used to collect data in all systems. GPS Pathfinder Office software was purchased to download data from the GPS units to the computer and perform necessary differential corrections to the data in addition to those automatically performed in the field.

Collecting Data

Data dictionaries were created and loaded into the Trimble GPS units. These dictionaries contained listings of the features that field-workers would encounter while collecting data on the water systems. It was important to the integrity of the final map products that meters, control valves, system valves, water mains, fire hydrants, pumping stations, tanks, wells, generators, springs, and treatment plants be located.

Collecting lines required an antenna mounted on the roof of a vehicle and connected to the GPS unit. Water department employees instructed WARC staff where the lines were located; staff members then drove along the lines as closely as possible. For particularly difficult areas, lines had to be added or connected back in the office.

Once the data was successfully collected and returned to WARC offices, it was downloaded, corrected, and exported as shapefiles and accessed using ArcGIS. For some water departments, AutoCAD files of the lines were obtained from the engineering firms originally hired by the water departments.

It was extremely important to have accurate road networks because the waterlines can cross roads multiple times. Editing road networks became essential for producing accurate maps that showed waterlines on the proper side of the road. Because lines needed to connect through the control valves, they were sometimes shifted slightly.

The maps produced by the project will save time, energy, and money by assisting responders from water departments to locate lines and features more quickly and efficiently. Future projects, similar to this one, are currently being planned by WARC. Water departments in surrounding areas served by the commission have expressed interest in also having their systems mapped. There are plans for integrating GPS and ArcGIS capabilities into hazard mitigation plans that will be revised for all seven WARC counties as well as a project aimed at mapping and restoring an historic tramway path on the grounds of Tannehill Ironworks Historical State Park in Tuscaloosa, Bibb, and Jefferson counties in the central-west portion of Alabama.

Make your comment:
Name:
Your comment:
Code: Please enter the code you see in the picture