Field Crews perform surveys for determination of existing land contours and structure locations for design and construction purposes. The horizontal control for most surveys is the North American Datum of 1983 (NAD83), California Coordinate System (CCS) Zone VI; currently adjusting to NAD83 (NSRS2007), Epoch 2011.0. The vertical control for most of our surveys is based upon the National Geodetic Vertical Datum of 1929 (NGVD29). County Survey will utilize the North American Vertical Datum of 1988 (NAVD88) if associated control can be recovered within the vicinity of the survey.

County Survey utilizes TopCon and Trimble Global Positioning System (GPS) receivers, total stations and data collection devices.

Types of Surveys Performed:

• Conventional Survey with handwritten notes and diagrams showing the existing topographic features
• Levels run (to determine elevations) performed using an engineering level, i.e. Direct Reading Automatic Level
• Electronic data collection survey with TopCon Total Station; the information collected will be coordinated using various combinations of “Magnet,” “MIcroStation,” “InRoads,” “EaglePoint,” and “Trimble Business Center (TBC)” software packages
• Aerial survey with aerial targets set at predetermined positions
• Precise levels in areas where there are problems with settlement or the benchmark control is inadequate
• Benchmark replacement work if a benchmark is going to be replaced
• Monument Inspections of Tract Maps and Parcel Maps
• Extensive GPS surveys with other local agencies, state and federal government, and various colleges and universities

Perform Construction Surveying for the following:

• Road construction staking; slope stakes, various grade stakes (sub-base, bottom oil, finish grade), con stakes and curb stakes
• Utility staking
• Structure staking
• Bridge staking
• Railroad staking
• Elevations of ground before and after construction for the determination of earthwork quantities/volumes
• Flood control channels, ditches and catch basins
• Monumentation
• Quality Assurance for inspectors on projects to assure the construction stakes of others were set within the accuracies necessary for the task
• In support of County projects, property surveys and setting of property corners