Gretna, LA, Used ArcGIS Reality Mapping Tools to Improve Infrastructure Management and Economic Development

The city of Gretna, Louisiana, is a small community just across the Mississippi River from New Orleans. While city staff had assembled good and useful datasets over the years, much of it was incomplete or difficult to access. Without a reliable system of record, planning infrastructure projects, maintaining assets, and delivering services to the public are challenging. 

The need for accurate data was especially urgent because Gretna faces repetitive flooding. Located at or below sea level but surrounded by land, the city depends on precise infrastructure and elevation information to better understand how to plan improvements and build long-term resilience. However, the workload for deeper analysis and modeling within the geographic information system (GIS) datasets Gretna’s IT staff relied on was too large for the small team to handle on its own. 

Michael Wesley, IT director for the City of Gretna, had some experience in GIS but mapping and modeling was not his primary job. “I’m doing 500 other things every day,” he explained. “I keep an eye on what’s going on with GIS, but I just don’t have the bandwidth.” 

The city government collaborated with ES2, an engineering and surveying firm and an Esri business partner based in Denham Springs, Louisiana. “We are very fortunate to have an administration that is forward-thinking,” said Wesley. “They understand that it’s worth the investment to bring in outside subject matter experts with the right skill sets. We leaned on ES2 to help us elevate our capabilities.” 

ES2 leadership sat down with Gretna senior staff, including the building and code enforcement, planning and development, and public utilities officials to understand what data was existing, and in what formats, and what was missing. “We developed a strategy to understand the datasets that they relied on every day,” said Andrew Milanes, president of ES2. “Then we put a plan around them to get them updated to ArcGIS Online.” 

To aid ES2 in geospatial advancements for the City of Gretna, they acquired a Blue UAS-compliant WingtraRAY drone, specifically designed for surveying and mapping professionals, to conduct aerial imagery flights for more accurate elevation surveys of sewer maintenance holes and other assets. This drone allows for data to be collected over large areas, including cities, thanks to its Federal Aviation Administration (FAA) Category 3 operations over people (OOP) approval. 

Mapping utilities in Gretna was a huge priority because it was clear from inspections that existing data wasn’t accurate. 

“We were flying drones for data collection and decided to go a step further and collect it in formats that are needed to produce a really high-quality Gaussian splat for the entire city,” said Rafael Fernandes, a business development lead at ES2. Gaussian splatting is a way to create hyperrealistic digital models from regular 2D photos. With ArcGIS Reality, Esri’s suite of photogrammetry software products, Gretna staff were able to turn raw aerial imagery into highly accurate 3D representations. 

“We empowered our staff and bought some mobile equipment using ArcGIS Field Maps for ad hoc data collection so they can go out and install a new water meter or make a repair and they can collect that information in real time,” said Wesley. “And we can monitor the progress of our mobile staff so if they have a question, they can call into the office and they can see exactly what is being worked on at that time.” 

Because the City of Gretna is only four square miles, “We flew the entire city with our WingtraRAY drone to acquire high-resolution imagery and lidar data,” said Milanes. “Then we used ArcGIS Reality to produce orthomosaics, Gaussian splats, and more,” he added. 

In one example, after ES2 delivered the city’s new 3D product, Wesley found an unexpected use case for the imagery. City staff used the tool to examine an illegal property from multiple angles, providing documentation to the court that helped verify that development and construction activities were happening but had not been properly permitted. 

The ability to have a quick 3D detail of the property provided evidence that otherwise would have gone unnoticed with outdated data. “I never intended to use the tool in a punitive way, but from a health and safety standpoint, it was important that we had that data available,” explained Wesley. 

Inspired by the unexpected code enforcement scenario, Wesley is now looking to train other departments on how to use the data created in ArcGIS Reality. “For economic development purposes, we could show prospective developers from outside of the city opportunities versus static photographs that don’t always show the whole story,” said Wesley.  

Additionally, the City of Gretna gathered other publicly available data sources in the city to prioritize various civic needs. For example, because of its proximity to New Orleans, many Mardi Gras parades start in Gretna. For large-scale event planning and permitting processes, having a complete 3D model will enable better support for public safety operations. 

“I am contacted by the police whenever there is a parade, so being able to see different staging areas from aerial imagery to position assets is critical,” said Wesley. He also hopes to use the high-accuracy imagery now available to Gretna staff for recording curb cutouts, sloped transitions at sidewalks for safety, without having to dispatch a mobile work crew. “Everyone in the city is very on board with embracing technology to further manage the city more efficiently and effectively and to be more responsive to our constituents.”