Surveying The Path For Roads Ahead - Highway Projects
From Fields To Homes - Land Development
Our Energy Is Forcused On Yours - Renewable Energy


Your partners in surveying, mapping and land information services since 1967


    Providing a full range of world-class surveying, mapping and land information services to domestic and international customers since 1967.


    We have an Ontario Land Surveyor check all plans and with a regular schedule of field inspections we ensure only the highest quality surveys reach our customers.


    Always committed to the latest in technological advances we believe in providing the best customer service to each individual project big or small.


    We are committed to the latest technological advances, but we are more committed to the old-fashioned concepts of quality and service.

Ontario’s First ISO 9000:2008
Registered Land Surveying Company


Callon Dietz started in 1967 as T.O Callon Limited and changed its name when Terry Dietz became a partner. Callon Dietz has a rich history of surveying in Middlesex County and throughout Ontario. We begin a typical project by researching available records from many sources to ensure we have first-rate information and evidence to complete the project. We then choose only the best combination of equipment to finish the project safely, accurately and efficiently so that we deliver the best product to our clients.


To provide a full range of world-class surveying, mapping and land information services to meet the expectation of domestic and international customers. In business since 1967, Callon Dietz Incorporated Ontario Land Surveyors is proud to be Ontario’s first ISO 9000:2008 registered land surveying company.


Technology powered by experience.

Callon Dietz Incorporated has provided land-surveying services to Southwestern Ontario since 1967. Established as the T.O. Callon Company, the firm became Callon Dietz Incorporated Ontario Land Surveyors in 1991.

Today, Callon Dietz partners on a wide variety of projects including gas line and other above-ground and underground services, highway reconstruction programs, subdivision and condominium surveys, digital terrain modelling and mapping. While London, Ontario, Canada is our base, we do business across Ontario.

Committed to quality.

By its very nature, surveying is about quality management. That’s why Callon Dietz developed a rigorous quality assurance process that is continually reviewed by external auditors to ensure compliance with ISO quality systems standards.

In 1998, we achieved ISO 9000 certification. Callon Dietz was one of the first in Canada, to achieve this internationally recognized designation.

What does this mean for our customers?

An Ontario Land Surveyor directly supervises all work done at Callon Dietz. An Ontario Land Surveyor checks all plans and a regular schedule of field inspections ensures that only the highest quality surveys reach you. We routinely audit all facets of our own practice and hire external auditors to verify our procedures.

In addition to ISO 9000:2008 certification, Callon Dietz is registered with the Ontario Ministry of Transportation’s Registry, Appraisal and Qualification System (RAQS). This system registers, prequalifies and tracks consultant performance, determining eligibility to bid for the
MTO contracts.


Training and Safety

Our employees are our most important resource. Technical staff are graduates of university or community college surveying programs. Our staff keep up with technology through continuing education and have current first aid, traffic control and WHMIS training, Crew Chiefs have been trained under the Occupational Health and Safety Act. Safety is our first priority on all projects.


We are always interested in talking to highly skilled individuals who share our mission and values. We welcome resumes from qualified applicants.

Contact us for Correspondence Details


Our services are in demand from legal and real estate professionals, residential and commercial property developers and individual homeowners. Understanding existing conditions is the critical first step in any project. An accurate engineering survey can provide a detailed inventory of the site, allowing you to make design decisions with confidence.


    Callon Dietz works with a number of utility companies to assist them in locating and constructing their new plant. For Union Gas, for example, we assist them with establishing property lines for gas main installation.

    Callon Dietz also works with a number of wind farm developers laying out turbines, access roads and distribution lines. Our expertise in handling large data sets over large areas help keep the construction process on schedule.


    Geodetic surveys define the height, latitude and longitude of a point, resulting in data that can be correlated to a known coordinate system. Using Geodesy, we create a 3D rendering that accounts for the size and shape of the earth.

    • Horizontal/vertical control
    • Control network design

    • GPS positioning
    • Precision leveling


    Whether it’s a highway project, city street, open field or city block, our experienced staff uses a combination of technologies for a correct and cost-effective product. Prior to beginning each project, accuracy specifications are reviewed to determine which measurement technology will best meet client specifications. We use a quality control process developed in-house that is certified to ISO 9000:2008. Once a survey is complete, we perform a thorough field check of the site, plan in hand.

    - Digital terrain modelling
    - Boundary confirmation

    - Plan compilation
    - Geodetic surveys


    At its most basic, a survey establishes or re-establishes property boundaries. At its most complex, a property prepared survey can settle legal disputes over property ownership.

    Callon Dietz is the first cadastral surveying firm in Ontario to achieve ISO 9000 certification. This means a lot to us and even more to customers who value quality.

    Our services are in demand from legal and real estate professionals, residential and commercial property developers, and individual homeowners. We prepare boundary plans required for development, severances and real estate transfers. Surveys can be supplied traditionally (paper) or in digital CAD format.

    - SRPR (Surveyor’s Real Property Report)
    - Reference Plan


    Land information services relate geo-spatial data to digital maps. Geo-spatial data includes everything from street line networks, addresses, and utilities to the components that make up the fabric of a specific lot such as roads, buildings and easements.

    Geo-spatial data is useful in applications as diverse as emergency vehicle routing, land use detailing, and market research. At Callon Dietz, we begin a typical Land Information project by mapping all of the specified real-world physical details and relating them to a world coordinate system. Our expertise combined with superior equipment facilitates rapid and accurate data acquisition.

    - Automated Mapping/Facilities Management (AM/FM)
    - Utilities mapping
    - Parcel mapping


    Callon Dietz prepares a significant proportion of the subdivisions and condominiums in Middlesex County. We also work in the neighbouring counties and as far as Niagara and Simcoe counties. We have extensive experience in subdivision design and registration, and have registered many types of condominiums including:

    - Standard Condominiums
    - Highrise
    - Townhouse
    - Detached
    - Commercial

    - Mixed use
    - Conversion of rental units, both townhouse and highrise
    - Vacant Land Condominiums
    - Leasehold Condominiums

    Defining ownership limits is quite complex in most condominium projects. Well-crafted plans accurately establish the boundary between individual ownership and common, or shared, elements. These include common elements that are used exclusively by an individual unit owner such as driveways, patios and courtyards. Any required easements are also defined. In phased developments, additional easements need to be defined to assure that all unit owners and utility companies have access to the facilities and services in the project.


    Callon Dietz has owned a mobile mapping system for the past year. We have utilized the system on 10 rural and 1 urban project. The system utilizes 2 Faro Focus X330 scanners, a Velodyne VLP-16 Puck and a Ladybug5 360⁰ spherical camera working with a Novatel Inertial Measurement Unit (IMU) and a GPS receiver to collect survey quality data.

    Chevrons are painted on the road surface and glass beads are sprinkled on the wet paint to increase reflectivity. Chevrons are placed at approximately 250 metre intervals and are tied to the project control network using a 1” total station and digital level. Audit lines are also measured at the same time as the chevrons are surveyed. The chevron control coordinates are used to align the scan data to the project control network using VG4D SmartLIDAR Explorer and/or ScanLook RT software. When we have reviewed the audited results on past projects and we have found that the LiDAR data matched the audit data at values much smaller than the 20mm vertical and 15mm horizontal accuracy specified by MTO.

    Features are extracted from the georeferenced and controlled locked LiDAR data in a number of software packages. Generally, features required for the survey are readily apparent in the scan data, but where needed, the digital imagery is used to clarify feature type i.e. electrical manhole vs sewer manhole and feature extent. Rock is easily extracted from the scan data but other features beyond the road shoulder can be difficult to identify in the scan data because of grass coverage. Generally speaking, we collect features beyond the shoulder using conventional survey techniques.

    Quality control of the scan data is very similar to conventional survey techniques. Profiles of centerline, driving lanes and pavement edges are reviewed for data irregularities. Cross sections are also reviewed for spikes and irregularities. Any discrepancies illustrated in the profiles and cross sections are investigated and resolved prior to delivering the survey.

    The mobile mapping system helps to minimize time needed on the road surface, thereby increasing worker safety. It also helps to collect hard surface data efficiently in the shoulder seasons so that schedules can be better maintained in late fall or early spring. The scan data and digital imagery is also useful for asset management. In many instances feature condition can be determined from the digital data eliminating a field visit.


Callon Dietz staff challenged the London engineering and surveying community to donate to the food bank and through our efforts we donated over 1200 pounds of groceries and $1,400 in support of the London Food Bank. Callon Dietz also matched $5 per bag donation. - October 2016

Callon Dietz was a proud sponsor of the Veteran's tent at the 2016 London International Airshow. - September 2016

Callon Dietz is proud to announce the opening of their North Bay office in June of 2016. Our North Bay office with help us expand our clientele in Northern Ontario while better serving our existing clients. For contact information for both the London and North Bay offices see the Contact Tab on the website. - June 2016


Current technology plays a key role in our day-to-day operations. Field crews are fully equipped with electronic total station theodolites, GPS receivers, Lidar Scanners and electronic bar locators, allowing us to handle any project on short notice.

  • Barrel Yards


  • Meadowlands of Sunningdale Project




  • Windmill Wind Farm Project

    WIND FARMS - (Ontario 6 Pack)

  • Amherst Island Ferry Project


  • 401 Tilbury Interchange


  • Chippawa Canal Project


  • 403 401 410 Interchange

    Highway 401/403/410 INTERCHANGE


Callon Dietz Inc.
41 Adelaide St. North, Unit 1 London, Ontario, N6B 3P4
591 Main St. East, Unit 102 North Bay, Ontario, P1B 1B7

Put your project in motion today and call on Callon Dietz to set up an appointment with one of our responsive and knowledgeable staff.

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© 2015 Callon Dietz. All Rights Reserved

Callon Dietz Incorporated
41 Adelaide St. North, Unit 1
London, Ontario, N6B 3P4

591 Main St. East, Unit 102
North Bay, Ontario, P1B 1B7