City Council Meeting Date: August 18, 2026
Date: August 10, 2026
To: Erin Rinehart, City Manager
From: Jonathan Wheat, P.E., Director of Engineering
Shannon Hicks, P.E., Assistant City Manager
Title
Consider Authorizing The City Manager To Approve A Professional Services Agreement For Engineering Services With Birkhoff, Hendricks & Carter, LLP. For The Channels And Floodplains Aerial Survey Project In An Amount Not To Exceed $544,100.00.
Body
Summary:
The purpose of this item is to conduct aerial drone surveys of the City’s drainage channels and to prioritize drainage projects.
Background:
The City of Carrollton has over 70 miles of channels and over 2300 acres of FEMA regulated floodplain. The maintenance and improvement of these areas have been at the discretion of the engineering and public works departments, with most considerations for capital projects being determined either by direct staff observation, work crew observations, or reports from residents of areas that need attention.
The Channels and Floodplain Aerial Survey project aims to more efficiently analyze, monitor, and identify areas within all the channels and floodplains that need to be repaired. The project aims to streamline that workflow through the following proposed scope of work:
1. Initial Data Review and Consulting - The consultant will meet with the City to review project goals and geospatial data, then develop an initial asset rating system for creeks and channels based on features such as floodplain data, crossings, slopes, and temporal erosion analysis. This rating system is flexible and can be updated as new data is gathered. The consultant can also apply machine-learning-based object recognition to improve feature identification and support more detailed future analysis.
2. Limited Initial Imaging - The consultant will use small unoccupied aerial systems (drones) to collect high-density LiDAR and high-resolution imagery, following FAA safety guidelines and avoiding restricted areas such as major highways and power transmission corridors. Data collection will occur during low-flow periods to maximize visibility of channel features.
3. Limited Data Processing and Asset Rating - The consultant will process LiDAR and imagery to create a bare-earth model of the areas of interest and extract key features using traditional and machine-learning methods. These results will be integrated into a geospatial asset management system and delivered to the City along with a letter report, classified point cloud, orthomosaic, and a digital viewer. This information will help the client identify priority areas for further investigation and plan maintenance funding more effectively.
4. Limited Bathymetric Mapping - The consultant will perform limited bathymetric mapping of select features within the areas of interest, focusing on sites larger than 1.5 acres and at least four feet deep. These bathymetric data will be integrated into the broader spatial model created from LiDAR and imagery to support temporal analysis of erosion or sedimentation. This information enhances the overall understanding of site conditions and changes over time.
5. Additional Limited Initial Imaging, Data Processing, and Asset Rating - The consultant will repeat the imaging and data-processing steps from earlier tasks after a City-defined period (1 to 2 years) to monitor erosion and deposition within the project areas. All assets will then be re-rated using the same methodology, with any changes documented.
6. Modification of the Asset Management System with Additional Features - After earlier tasks are completed, the consultant may modify the asset management system to include new features identified in the data or requested by the City, using machine-learning algorithms if those features are detectable in previously collected remote-sensing data.
The city obtained proposals from three different consultants, and using a professional services qualification-based selection, determined that selected Birkhoff, Hendricks & Carter LLP were most qualified and prepared for the inaugural aerial survey of the City’s channels and floodplains.
Financial Implications:
Birkhoff, Hendricks & Carter, LLP. has submitted a proposal to the City of Carrollton to provide engineering design services for the Channels And Floodplains Aerial Survey Engineering project in an amount not to exceed $544,100.00.
Impact on Community Sustainability:
This project supports the City Council’s strategic objectives and vision of building a community that families and businesses want to call home by:
• Improving community safety by identifying erosion, structural risks, and flood-related vulnerabilities within channels and FEMA-regulated floodplains, helping protect residents and businesses from future hazards (Hospitality; Healthy).
• Strengthening infrastructure reliability through comprehensive LiDAR, imagery, and bathymetric mapping that supports long-term drainage system maintenance and investment (Economical).
• Enhancing operational efficiency by streamlining how Engineering and Public Works monitor, prioritize, and manage drainage assets, allowing city staff to provide faster, data-driven service (Optimize).
Staff Recommendation/Action Desired:
Staff recommend authorizing the City Manager to enter a professional services agreement for engineering services with Birkhoff, Hendricks & Carter, LLP. for the Channels And Floodplains Aerial Survey Engineering project in an amount not to exceed $544,100.00.