Topographic Mapping Services

The Vendor is required to provide preparing topographic maps within an existing plant using ground survey or GPS techniques.
- Work included:
• Ground control survey and calculations.
• Topographic surveying within an existing plant.
• Preparation of a plat of survey for the survey limits and property involved in the work.
• Installation of permanent survey monuments
• Preparation of a finished topographic map of the survey.
- Planimetric features shall be shown on the topographic maps:
• Limits of paved and unpaved surfaces including, but not limited to, roads, curbs, driveways, parking areas, sidewalks and trails, etc.
• Centerline and edge of roads and driveway aprons.
• Roadway curbs, including top of curb, back of curb, and gutter flowline.
• Grade breaks, top and bottom of slopes, and dikes.
• Foundations and support columns for elevated structures.
• Buildings.
• Top of foundations or top of concrete of all buildings.
• Aboveground tanks.
• Fences and gates.
• Give gate width and type.
• Guardrails, walls and guard posts.
• Retaining walls.
• Existing drainage culverts, including invert elevation, size and material type.
• Utility poles, guy poles, "h" frame structures, transmission towers.
• Rim elevation of manholes, catch basins, and curb inlets.
• Stormwater pipe size and elevations of culverts, and if accessible, in structures.
• Fire hydrants and isolation valves.
• Lift stations.
• Electrical vaults and valve boxes (at or above grade).
• Above grade pipe lines.
• Supports for pipes.
• Pipe trenches.
• Invert and top elevation of drainage ditches and swales.
• Invert elevation of culverts and top of headwalls.
• Centerline and width of ditches, limits of ditch riprap, banks of ponds, streams and waterways.
• Property lines, easements, and rights-of-ways, including plat of survey.
• Monumented field control.
• Monitoring wells and geotechnical and environmental sampling locations.
- Ground surveying and mapping
1. Surveying:
• Topographic surveying may be done by ground surveying techniques or by GPS surveying techniques or a combination of both.
• The purchaser’s onsite personnel will coordinate the field work and will identify the location of existing monuments and benchmarks.
2. Mapping:
• Topographic mapping shall meet the national map accuracy standards as described herein.
• The plotted position of each coordinate grid line shall not vary more than 1/100 of an inch from the true grid position.
• Each horizontal control point shall be plotted on the map to an accuracy of 1/100 of an inch of its true position.
• Ninety percent of the elevations determined from solid-line contours shall have an accuracy with respect to true elevation of one-half contour interval or better, and the remaining ten percent of such elevations shall be not in error by more than one contour interval.