Topographic Surveys

Topographic Surveys by Conventional Methods

Topographic surveys can be done by both aerial surveying methods or by conventional surveying methods.  Which type of method is used is dependent on the size of the parcel of land and the visibility of the ground from the air.  Michael Dequine and Associates, Inc. provides both types of topographic surveys.

All topographic surveys done in house by conventional methods are performed by Michael Dequine and Associates, Inc. staff.  Topographic surveys by conventional methods include horizontal and vertical control surveys, field surveys to locate spot shots on a specific grid interval throughout the survey area, and field surveys to locate high and low points, tops and toes of slopes, ditches, fences, visible utilities, manholes, drain inlets and outlets, water valves, and other pertinent facilities on site.    Trees measuring over a specific diameter can also be located and tagged.  Field surveys will also include all visible surface evidence of underground utilities including water valves, air release valves, blow-off valves, sewer and drain manholes, drain inlets, sewer clean-outs, electrical boxes and pedestals, transformers, street lights, street light boxes, telecommunication boxes and pedestals, and utility poles and guy anchors.    In addition, sewer and drain manholes and drain inlets are dipped to obtain the pipe invert elevations and pipe sizes at all manholes, unless traffic conditions, permit requirements, or physical obstructions (such as bolted or welded down lids) prevent us from obtaining access to the required areas.  We also have the capability to locate underground utilities using ground penetrating radar or electro-magnetic induction by partnering with one of our many sub-consultants.

Michael Dequine and Associates, Inc. will typically provide “Control Targets” to our aerial survey sub-consultants.  Control targets consist of a spike or nail in the ground with a large plastic or painted cross centered on the spike or nail.  Field surveys are performed by Michael Dequine and Associates, Inc. to identify the horizontal and vertical positions of the control targets and to take a series of spot shot elevations throughout the property.  The control point information is provided to our aerial survey sub-consultant prior to the actual flight.  During the flight, photographic images are taken from the plane, helicopter, or drone and adjusted using the control targets provided by Michael Dequine and Associates, Inc.  We receive the topographic survey drawings in digital format from our sub-consultant and then verify that information using the ground shots we took previously.  After a field review to verify that the maps are complete we typically provide a paper copy of the topographic survey that has been stamped and signed by a California Licensed Land Surveyor.

Past Projects:

Aerial Topographic Surveys

  • Selby Terminal, Crockett, CA
  • Liberty project, West Sacramento, CA
  • Port of Stockton, Stockton, CA
  • Oroville Industrial Park, Oroville, CA
  • Parklands South, Rocklin, CA
Conventional Topographic Surveys

  • Crispin Cider Works, Colfax, CA
  • City of Galt Police Department
    (Firearms Training Center, Galt, CA)
  • Contra Costa Water District, Oakley, CA
  • 4 mountaintop surveys, Winnemucca, NV