Questions About Survey
Below you will find answers frequently asked questions regarding land surveyors, land surveys and records.
Can the City of Portland help me?
The city does not perform survey work on private property. If you want your property surveyed, you must hire a private land surveyor.
Who can legally perform a land survey?
In the State of Oregon only a Professional Land Surveyor (PLS) can legally assume the responsibility for a land survey. The Professional Land Surveyor is an individual whose highly specialized background, training and skills have been rigorously examined and who has been licensed by the State of Oregon to practice Land Surveying
Where can I find a Surveyor?
There are several different options for locating a PLS:
- The yellow pages (Surveyors-land) and the internet should have listings of surveyors in the Portland area.
- Many surveyors are found through the personal recommendations of satisfied clients, or through attorneys, real estate companies and title companies who frequently handle real estate transactions.
- The Oregon State Board of Examiners for Engineers and Land Surveyors, is the licensing agency for Engineers and Land Surveyors. As such they maintain a list of Licensed Professional Land Surveyors throughout the state. Select "Find a Licensee" to begin your search. Be sure to select "Professional Land Surveyor" under license type, and you will generate a much more manageable list if you limit the search by city and state.
- The Professional Land Surveyors of Oregon (PLSO) also maintains a directory of surveyors. Check the services directory in their web page for more information.
Where do I find Records of Survey?
The various county survey offices are singularly responsible for maintaining and archiving survey records. If you are looking for a specific survey or record you are encouraged to contact them directly:
- Multnomah County Surveyor's Office
- Clackamas County Surveyor's Office
- Washington County Surveyor's Office
How much will a survey cost?
Survey work contains a large number of variables such that are impossible to account for prior to beginning work. When you call a PLS to arrange work to be done on your property, ask for an estimate for the work to be done.
Additionally, the City of Portland has contracted out free mediation services for our residents through Resolutions Northwest.
Benchmarks are survey markers that provide a point of particular elevation used as a reference for determining elevations of other points in a survey. They are used by surveyors, engineers, planners, and contractors for establishing elevations for planning, designing, and/or construction of various projects.
The City of Portland is responsible for establishing and maintaining a network of benchmarks throughout the city, each having a known elevation expressed in feet in the City of Portland’s own datum (established in 1896).
Most of the City of Portland’s Benchmarks are brass disks about 2 ½" in diameter, and all are marked "City of Portland Bench Mark No. nnnn " and usually set in the curbs of streets. Occasionally you’ll see larger disks of 3 ¾" diameter which are "Class A" monuments, and some benchmarks are set in retaining walls, bridge wing walls, culvert headwalls, concrete steps, or wherever the most stable and accessible placement was determined to be for a specific location.
You might also see benchmarks similar to those of the City of Portland’s but with another governmental agency’s or private firm’s name stamped on it. Occasionally the City of Portland Benchmark Book will refer to these monuments and provide elevations, but more often you’ll have to contact the appropriate institution for more information. The benchmark numbers the City assigned to outside agency monuments are for indexing purposes only; PDOT does not stamp a City of Portland benchmark number on other agencies' monuments.
Online Benchmark Book
To find benchmarks:
- Open portlandmaps.com.
- Navigate to your project area either by zooming and scrolling or by using the address search bar at the top right.
- Click on the taxlot to open the query panel.
- Scroll down to "Transportation" and select that.
- Then scroll down to "Benchmarks" and click the button.
Once you have done that the benchmark layer will populate and it will provide a table of all benchmarks within 1000' of the selected taxlot.
If you have any questions regarding benchmarks or to report a missing, destroyed or found benchmark, please contact the City of Portland, Bureau of Transportation Survey via email at email@example.com.
Vertical Datum Conversions
|COP Datum||- 1.375||= USC&GS 1947|
|COP Datum||- 1.375 *||= NVGD 29/27|
|COP Datum||+ 2.10 *||= NAVD 88|
|COP Datum||- 2.92||= Morrison Bridge Weather Gage|
|COP Datum||- 3.22||= Stark St & Vancouver US Engineering Gage|
|USC&GS 1947||+ 1.375||= COP Datum|
|NVGD 29/27||+ 1.375 *||= COP Datum|
|NAVD 88||- 2.10 *||= COP Datum|
|Morrison Bridge Weather Gage||+ 2.92||= COP Datum|
|Stark St & Vancouver US Engineering Gage||+ 3.22||= COP Datum|
* Approximate Conversions
Survey Related Forms & Documents
The following documents are intended for use by City of Portland personnel and its contractors.