Introduction
We recently completed an exciting mapping project along the Willamette River in Portland, Oregon, showcasing how modern technology can transform traditional surveying. This project for Severson Environmental Services demonstrates how our team at Redefined Horizons applies innovative solutions to solve complex environmental challenges.
The site in question is an 80-acre industrial property where GASCO, the primary tenant, has been working for decades to prevent contaminated groundwater from entering the Willamette River. After 30 years of planning, they're finally ready to replace their current groundwater mitigation system with a 150-foot deep slurry wall - a massive undertaking with a design that requires precise mapping and planning.
The Challenge: Making Sense of Fragmented Data
Before we could help design the new slurry wall, we needed to overcome several significant challenges with the existing site data:
- Piecemeal information collected over 20+ years.
- Outdated surveys that no longer reflected current conditions.
- Inconsistent control systems create geospatial referencing issues.
- Dense vegetation along the waterside makes ground surveys difficult.
As our principal Brian Leiser, explained: "They didn't have one holistic view of the current conditions. Some of the features in previous surveys had either disappeared or been replaced and modified."
What began as a request to identify 50 additional features quickly evolved into a comprehensive resurvey of the propose construction zone, ultimately capturing 250 individual features.
Our High-Tech Approach: Drones Take Flight
To tackle this challenge efficiently, we deployed a powerful combination of aerial and ground-based technologies:
UAV Technology
We utilized two specialized drone systems:
- Inspired Flight IF-1200 Alpha - A heavy-lift platform carrying our Phoenix Ranger Regal Mini LiDAR sensor for precise terrain mapping that could penetrate vegetation.
- Inspired Flight IF-800 Tomcat - Equipped with a Sony 61-megapixel full-frame RGB camera for extremely detailed orthophotography.
Ground Technologies
To complement our aerial data, we also deployed:
- Total stations for direct ground surveying of critical infrastructure.
- 360-degree cameras for comprehensive waterside documentation.
- 22 ground control targets plus numerous photo-identifiable points for precise georeferencing.
The Game-Changing Benefits of UAV Technology
Twenty years ago, this project would have looked dramatically different. As Brian noted: "The aerial imagery would have required a manned aviation company, and the topography would have taken several weeks of direct surveying on the ground."
Our approach delivered significant advantages:
- Efficiency - Completed in days what would have taken weeks with traditional methods.
- Precision - Achieved accurate one-foot contours even in vegetated areas thanks to LiDAR.
- Detail - Low-altitude, high-resolution photography allowed us to identify small features like manholes and even read painted numbers on infrastructure.
- Accessibility - Remotely sensed 99% of the location data, avoiding access issues in secured areas.
- Comprehensiveness - Created a single, unified geospatial dataset across the entire site.
Creating Value Beyond Basic Mapping
What truly set this project apart wasn't just the technology we used, but how we delivered the final product to make it maximally useful for the client.
"One of my requirements for the report was that somebody could take it, whether in electronic or printed format, and be able to locate everything they needed without having to have a CAD drawing or any location data or a GNSS rover," Brian explained.
We organized our deliverables to create lasting value:
- Organization Into Zones - Divided the project area into five logical zones for easy navigation.
- Element identifiers - Assigned unique IDs to all 250 features for cross-referencing.
- Comprehensive documentation - Created a 118-page report with photography, location data, and detailed descriptions.
- Dual-format compatibility - Ensured CAD files and reports could work together or independently.
This approach proved especially valuable when the client later identified additional features they wanted data on. "I went back to the LiDAR and imagery we obtained...and we were able to extract the data we needed and add it to the CAD files without having to do a revisit," Brian noted.
Overcoming Challenges Through Planning and Adaptability
The project wasn't without its challenges. We faced:
- Weather constraints - Working in Portland in January meant limited daylight, low temperatures, and fog.
- Security protocols - Navigating the high-security requirements of the neighboring semiconductor manufacturing facility.
- Coordination complexity - Managing teams for the UAV LiDAR, UAV red/green/blue image, and ground survey data acquisition teams.
- Data integration - Combining remote sensing, ground surveys, and terrestrial images/video into a single integrated geospatial data set.
One of our biggest lessons learned was the value of pre-planning. "That initial recon visit ended up being crucial," Brian emphasized. "Without that, we probably would have burned up one full day of our ground survey time with four men on the ground just figuring out where we were and where we had to go."
Looking Forward: Lessons for Future Projects
This project yielded valuable insights that we're applying to all our work moving forward:
- Conduct thorough reconnaissance before full deployment.
- Establish clear file naming conventions and photography standards.
- Implement better flight tracking to avoid mission errors.
- Build in redundancy by collecting data from multiple sensors.
- Invest in extensive ground control for maximum accuracy.
- Consider automated reporting tools to streamline documentation.
The Future of Environmental Mapping
The Gasco Portland project demonstrates how modern UAV technology, when properly applied, can transform environmental site assessment and remediation planning. By combining aerial LiDAR, high-resolution aerial photography, and traditional surveying in a thoughtfully integrated approach, we're able to deliver more comprehensive, accurate, and useful data than ever before.
For sites with complex histories, security constraints, or challenging terrain, this approach doesn't just save time and money—it provides better information for critical decision-making. As environmental remediation projects become increasingly complex, we're proud to be at the forefront of applying these technologies to protect natural resources like the Willamette River.
This blog post was created based on interviews with Brian Leiser, Principal at Redefined Horizons. The GASCO Portland Slurry Wall Project is an example of Redefined Horizons' ongoing commitment to innovation, continuous improvement, and environmental stewardship.
Redefined Horizons helped a land owner in Oridina California perform a lot-line-adjustment. The lot-line-adjustment created a new buildable parcel. The client didn’t realize they already owned two legal parcels. They first asked for a minor subdivision (or parcel map). Our team saved the client significant money by proposing a lot-line-adjustment instead of a parcel map. Our services on the project included a boundary survey, topographic survey, completion of the lot line adjustment application, preparation of land descriptions and land title work. We submitted the initial lot line adjustment application less than 15 working days from the start of the project.
Redefined Horizons performed a boundary survey and UAV aerial mapping of a small homesite and pasture. The parcel we surveyed is in Byron, California, south of Highway 4. We also provided expert witness services and review of chain-of-title documents.
The owner of two auto dealerships at the Tracy Mall hired Redefined Horizons to perform a minor subdivision (parcel map). As part of the minor subdivision, we split an existing parcel into two parcels. The services we provided as part of the subdivision included a boundary survey, easement mapping, a topographic survey, preparation of a tentative parcel map, preparation of a final parcel map, and monument placement. We also prepared land descriptions for new easements. The easements were for parking, utilities and drainage.
When a real estate broker needed a boundary survey of a single family home in an upscale neighborhood of San Mateo in just five working days, she called Redefined Horizons. We quickly performed the work needed to resolve the parcel boundary, create a high-resolution low-altitude color UAV orthophoto, and provide an existing conditions exhibit. Our tasks on the project also included monument placement, preparation of a record-of-survey map, and coordination with a land attorney to resolve a long-standing boundary encroachment.
The Redefined Horizons team provided a boundary survey and ALTA survey for a renewable energy project on this 28 acre parcel in Central Oregon. The site will provide grid energy storage. Tasks completed on the project included a field survey of over a dozen property corner monuments and review of 20 exceptions to title insurance coverage. A high-resolution low-altitude color UAV orthophoto was also provided as part of the survey.
Redefined Horizons was hired to prepare a boundary survey and site plan for a lot-line-adjustment of several agricultural parcels just outside of Visalia, California. Tasks completed on the project included preparation of land descriptions and plats for the lot-line-adjustment. The survey work products were submitted to the County of Tulare within 5 working days of notice-ot-proceed.
Redefined Horizons surveyed a small industrial parcel in the City of Hayward to support the design and construction of a new steel frame building. Tasks performed on the project included a boundary survey, topographic survey, preparation of an existing conditions exhibit, coordination with the structural engineer and coordination with the civil engineer.
Redefined Horizons was hired to perform a boundary survey of a 20 acre pasture outside of Hilmar, California as part of a real estate transaction. The survey was completed and an existing conditions exhibit delivered to the buyer of the parcel in just 10 working days. Our tasks on the survey also included setting property corner monuments and preparing a record-of-survey map.
Redefined Horizons performed a boundary survey and topographic survey to support the redesign of a health care facility in Orangevale, California. Tasks completed on the project included preparation of drawings to support design of building additions and site improvements.