Aug 07, 2019

Views From Above

Indiana city improves storm water billing & increases revenue through aerial imagery

The city of Carmel’s infrastructure program includes high-resolution aerial imagery to monitor storm water infrastructure.
The city of Carmel’s infrastructure program includes high-resolution aerial imagery to monitor storm water infrastructure.

A suburb of Indianapolis, the city of Carmel, Ind., is home to the Meridian Corporate Corridor (U.S. 31), which has Indiana’s second-highest concentration of office workers after downtown Indianapolis. The walkable, bike-friendly and sustainable city has consistently grown in residential population and business, namely corporate headquarters, during the past 20 years. More than 100 corporate headquarters are located in Carmel, and the population has grown from 30,000 people in 1996 to nearly 100,000 people today.

The city is in the middle of an aggressive, four-year, more than $300 million concentrated infrastructure improvement program that includes new roundabouts, intersections, interchanges, and storm water management and drainage projects. 

“The purpose of these projects is to continue to improve our infrastructure and our transportation system by making our streets safer for motorists and better for the environment," said Jim Brainard, mayor of Carmel. 

Carmel is one of the fastest-growing communities in the country. Considering the growth expected for 2017 and 2018, the city needed a visual tool better able to manage the city’s expansion projects across several government departments. The Carmel Engineering Department turned to Nearmap for frequently updated aerial images of the city to integrate with its existing applications, including ArcMap and ArcGIS. The high-resolution imagery now aids data accuracy, verifies customer claims, educates developers, enforces compliance and prepares presentations for internal government meetings. Through impervious surface digitization and internal audits, the Carmel Engineering Department collected $60,000 in revenue from 2015 through 2017. Aerial imagery also has proven invaluable in assisting the engineering department staff in solving constituent problems.  


Outdated & Inaccurate Data

The Carmel Engineering Department lacked an up-to-date, high-resolution base map for its data platforms. Updated maps and GPS information are a crucial part of accurate data representation to determine storm water billing.

At the time, the department used aerial images taken annually by the county. By the time the imagery was processed and delivered six to eight months after capture, the images were a year and a half out of date and did not represent new developments in the city. Because of this lag in the process, it was impossible to calculate storm water billing fees for new developments, which meant a loss in revenue. Other options included geoprocessing or manual measuring and surveying, which were too costly and time intensive. In addition, the previous aerial imagery the county provided was taken at a less-than-optimal 6-in. resolution, which made it difficult to see details. 

“Originally, when the city's storm water data was mapped, it didn't convert into ArcGIS properly,” said Shane Burnham, GIS technician for Carmel. “The pipe data was off by 15 to 20 ft. Combined with the low-resolution imagery, it was nearly impossible to tell the difference between a smudge or storm inlets.”


Data Accuracy & Image Quality

The imagery now is updated four times per year. As soon as a property is completed and water meters are installed, the department can digitize that information into ArcGIS and ArcMaps to start billing. Instead of realizing revenue annually, the department sees revenue quarterly. 

“It’s critical that the imagery keep up with our fast-growing area, and we see progress in real-time at a 3-in. resolution,” said John Thomas, storm water administrator for Carmel. “We measure and bill with confidence knowing that we have accurate and clear infrastructure information. We are no longer referencing imagery that is two years old.” 

The city now can earn revenue quarterly, rather than annually.
The city now can earn revenue quarterly, rather than annually.

Increased Benefits

With aerial captures, the department can quickly and successfully verify damage claims made by citizens. For example, if a citizen makes a claim that the city created a pothole or damage to their property while working on a city project, the city can look back at the historical aerial captures to verify when the pothole originated. 

“Sometimes we find that the damage was there before the city project had even started. Using past imagery to validate that information makes it easier for us to determine presented discrepencies and help the citizen find a solution to the problem,” said Joshua Kirsh, engineering administrator for the city of Carmel. 

Carmel has become a hotspot for developers and real estate investors. Often these developers are not from Carmel and are unfamiliar with the area and land. The city has used the aerial imagery to educate developers by displaying existing drainage patterns, wetlands and soil types, all through detailed aerial captures. 

The imagery is updated four times per year.
The imagery is updated four times per year. 

The Carmel Engineering Department has specific codes and requirements to keep the city water drainage and quality in check. Each new development is required to install two post-construction storm water treatment measures to remove pollutants from runoff before that runoff exits the site. The department can use historical imagery to see if the surfaces were protected during the construction process. 

“With historical imagery, we can determine if construction crews were tracking dirt on the pervious asphalt. This gives the city a backbone to enforce compliance and saves the time of going back and forth with these companies. Situations that would sometimes take years to resolve are now sorted out in one meeting,” Thomas said.

After implementing aerial imagery, the department earned approximately $60,000 in unclaimed revenue in the first quarter of 2017. 

“When searching for a GIS solution, we wanted a service that paid for itself,” Burnham said. 

Because of the success of integrating aerial photos in the Engineering Department, other departments within the city are taking notice and are finding ways to use the service, too. The team sees potential uses in planning, zoning, code enforcement and maintenance, among other possibilities. 

“We keep finding new ways to use the imagery,” Thomas said. “When we show people what we’re doing with it, they immediately ask, ‘Why aren’t we utilizing this?’

About the author

Tim Frank is vice president of marketing for Nearmap U.S. Frank can be reached at [email protected]