Improved Location Accuracy Enables Hydraulic Modeling

A water district in Kentucky increased the locational accuracy of assets in its GIS using mobile mapping so that its engineering team could use the data for hydraulic modeling. GIS also helps the district streamline operations and improve customer service.

Warren County Water District (WCWD), based in south central Kentucky, offers water and wastewater services over a 530 square mile area between Nashville and Louisville. Every day, the utility delivers more than 8.1 million gallons of drinking water across 1,194 miles of water lines, while its wastewater system transports 2 million gallons of wastewater across 218 miles of sewer line.

In addition to this system, WCWD manages the water systems for Simpson County Water District and Butler County Water System through a joint operations agreement that brings the total length of water main to just over 2,100 miles across 1,200 square miles. Each of the three utilities has a separate board of directors, but their operations are streamlined through GIS and one customer information system (CIS).

When moving from paper map books to web maps, WCWD digitized its original as-built drawings. Now engineers can access the drawings by selecting an asset to open its pop-up and then clicking a hyperlink from the attributes. The hyperlink launches an internal web mapping application where historical data can be viewed.


The Original Move to GIS

In the past, WCWD used to equip its field crews with 75-pound paper map books to navigate to service order work sites. Although the map books got the job done, they were cumbersome and time-consuming to use—especially for new employees.

In 2006, WCWD decided to modernize its operations and hired its first full-time GIS employee along with a contractor to kick-start digital mapping. First, WCWD digitized thousands of paper as-built drawings and georeferenced them to GIS features. The contractor then went to the field to map all the aboveground assets, using subfoot-grade mapping equipment.

Once the locations were postprocessed, WCWD IT and GIS manager B. J. Malone uploaded them into the GIS and snapped features to the new accurate locations. Malone and the contractor mapped the WCWD system. Subsequently, Malone brought field mapping in-house to map the Simpson County and Butler County systems.

“At that point, we had all of our aboveground assets—every valve, meter, pump station, hydrant, and maintenance hole—mapped with subfoot accuracy,” Malone said.

Hydraulic Modeling for Wastewater Assets

Subfoot asset accuracy was acceptable for mobile workers, but it was not good enough for the engineering team to use in hydraulic modeling. Hydraulic modeling relies on extremely accurate elevation values that would require centimeter-level accuracy in the GIS.

Extracting elevation values from paper as-builts was time-consuming and sometimes frustrating for WCWD’s engineers. The drawings often contained inaccurate slope measurements. Malone realized that WCWD could benefit from improving the accuracy of its GIS data even further.

To test the idea, Malone hired another contractor to remap the utility’s wastewater assets with centimeter-grade accuracy. In this pilot project, the collected data had to be postprocessed to obtain the desired accuracy, before being imported to update the GIS. When these tasks were completed, Malone had the information at a level of quality that his engineers could use. His next challenge was to find a simpler way to maintain this level of accuracy in-house—and potentially expand it to all assets.

Additionally, in 2009 WCWD had begun utilizing GIS data in the field with a Windows-based mapping application on laptops. While the laptops were a great tool, mobility in the field was limited to the truck. Malone believed the new in-house mobile mapping solution could overcome both remaining challenges.


Within ArcGIS Field Maps, service crews can select a hydrant and then launch a hydrant flow testing form within ArcGIS Survey123. A dashboard, created using ArcGIS Dashboards, shows the results of hydrant flow tests.


Real-Time, Accurate Mobile Data Collection with ArcGIS

Around this time, Malone noticed Esri’s mobile data-collection apps were becoming not only very popular but also incredibly robust. Originally, Collector for ArcGIS and later ArcGIS Field Maps, combined with ArcGIS Survey123, could enable GPS-supported data collection directly into the GIS, in real time and with the data already in GIS format.

“We already had Esri software, so migrating to Esri mobile apps made sense to us,” Malone said. “Everything was native to the GIS format, and it enabled us to give our [staff] in the field something with GPS capabilities on a device they were comfortable using.” The utility gave its field crews both iOS and Android tablets—based on user preference—running Esri apps.

The last remaining component was a compatible, centimeter-grade Global Navigation Satellite System (GNSS) receiver that worked with the ArcGIS apps. After consulting with a nearby water district, Malone chose the Arrow Series GNSS receivers made by Esri partner Eos Positioning Systems. The Arrow Gold receiver provides real-time, centimeter-grade locations through a combination of GNSS positioning and real-time kinematic (RTK) differential correction processing. It could be used with the Kentucky Real Time Reference Network, the local free RTK network. Going this route would eliminate both postprocessing and manual data uploads to the GIS.

“When Eos came along and made that marriage with Esri so that everything works natively in Esri apps, that became a huge time-saver for us with both data collection and postprocessing,” WCWD GIS analyst Josh Smith said. “It streamlined both office and [mobile] workflows by keeping everything in one place and eliminating the need to pass data through multiple applications.”

The Arrow Gold receiver also offered a feature for maintaining survey-grade accuracy in remote areas where internet service via the cellular network was spotty.

“We went to some of the most remote areas of our system to test out the Arrow GNSS receiver, and it just worked,” Malone said.

Streamlined Data for Hydraulic Modeling

Today, WCWD has mapped its wastewater assets with centimeter-grade accuracy, and its aboveground assets—for all three systems—with subfoot accuracy. This year WCWD staff have deployed RTK data collection for all newly constructed assets. Meanwhile, engineers have engaged a consultant who will now use RTK elevations to develop a wastewater hydraulic model. The engineers are already using the data for other workflows, such as system-modification planning and historic leak tracking.

The field team members have also started to realize gains from having accurate, digital maps with them at all times. They are able to find things faster and can access what they need on one device. It has eased everybody’s mind.

WCWD has since hired one more full-time GIS employee to support Malone. The district estimates that of the 74 employees at the utility, 65 to 70 use GIS regularly. The meter-reading team members use the maps to navigate to existing meters and aid the installation of 41,000 new smart meters by WCWD. Meter data is stored with locations in the GIS and integrated in the CIS.

Customer service representatives (CSRs) use the data to respond faster to customer inquiries, generate service orders for field crews, and respond to contractor requests for asset information in specific areas. “We save a ton of time for our CSRs,” Malone said.


Field team members have realized gains from having accurate, digital maps with them at all times so they can find things faster and access what they need on one device.

Maps Help WCWD Keep Up with Requests to Locate Assets

The aboveground data has proved so valuable that WCWD has started to also map its underground assets. Today, developers and inspectors are equipped with ArcGIS Field Maps and Arrow Gold receivers to map assets in new subdivisions before they are buried.

For call-before-you-dig requests to locate existing assets, WCWD equipped its asset-locating teams with the same technology. The teams now use the maps of aboveground assets (e.g., valves, meters) to more quickly find buried water mains. In places where underground assets are already mapped, the teams navigate right to these assets. Although teams still perform traditional field validation, the time savings using the new system have been huge. Malone estimates that demand for fiber-optic cable installation has caused locate calls to approximately quadruple in the past year alone.

“With the increased number of locate requests that we currently have, I don’t think we would have been able to keep up the pace without these maps,” Malone said. “It has really streamlined that process and helped us locate assets more quickly.”

So far, WCWD has mapped more than 68,000 underground points across 51 miles of pipe. The utility has also purchased two ground-penetrating radar (GPR) devices and equipped them with ArcGIS Field Maps on Android and an Arrow Gold receiver. According to WCWD operations supervisor Travis Watt, having the RTK capabilities of the Arrow Gold along with the GPR devices and Field Maps has been amazing.

“It provides my team with two methods to locate underground assets,” Watt said. “At times, [the team] can navigate nearly down the exact center of buried water mains.”

Malone says he is grateful that the utility’s employees and leadership see the value of GIS. “We really try to be GIS-centric, to build the workflows and applications that enable us to make smarter decisions. When we added accurate locations into the GIS, that’s what really paid off for us. Now our field and office teams are realizing the efficiency gains, and we’re making their lives a little easier. That’s been a win.”


About the author

Christa is an experienced water industry professional with 20 years of success using and promoting technology to solve problems in the water industry. She is recognized for water industry thought leadership, strategic thinking, and building success with organizations across the globe. She is a passionate GIS advocate, lifelong learner, and collaborator. Christa has a diverse background, with experience in conversion from paper to digital, drafting and design of engineering plans, superfund site remediation, environmental mitigation, managing geographic information systems, and implementation of new technology. She is a certified GIS Professional and holds bachelor’s degrees in Geography & Environmental Studies and a graduate degree in Geography.