7,500-Acre Mapping and Drainage

Project Type:
  • Survey
  • Flood Control
Budget: $295,800
Service Performed:
  • GPS Control Network
  • Contour Mapping
  • Aerial Mapping Coordination
  • Horizontal/Vertical Control
  • Utility Coordination
  • Local/State/Federal Coordination
  • Hydrology/Hydraulics
  • Drainage Study

This desert mapping project consisted of a 7,500-acre site in San Bernardino
County. GCW set 87 aerial panels to control horizontal and vertical mapping
aspects along with 16 blind targets and 25 random points to verify aerial mapping
control for 1-ft contour intervals at 1 inch=40 feet scale mapping. Crews also
set 37 aerial panels to control horizontal and vertical aspects of 1,000-ft wide,
18-mile transmission line corridor for 3-ft contour intervals at 1 inch=40 feet scale
mapping, and 33 aerial panels to control horizontal and vertical aspects of 11
miles of access route corridor for 1-ft contours at 1 inch=40 feet scale mapping.
Remote location of site required that horizontal and vertical control be transferred
to the project area using GPS static observation and networking methods using
California Spatial Reference Center continuously operating reference stations.
Data from these stations was downloaded daily and processed with Trimble
Business Center v2.70 software.

GCW also prepared an existing condition technical drainage study to assess site
feasibility for a proposed development, as well as serve as a basis for locating
infrastructure components. Approximately 18 miles of proposed access road
was planned to extend from the project site to nearby utility hubs. Proposed
drainage improvements included culverts crossing the proposed access road at
topographical low points. Hydrologic and hydraulic models included analysis of
a 60 sq mile drainage tributary to the site and access road to establish drainage
constraints. Project required coordination with San Bernardino County, USACE, and
local utilities.