Division 13-03-003
Topographic Survey

Sections:

13-03-003-0001    Definition

13-03-003-0002    Qualifications

13-03-003-0003    Benchmarks

13-03-003-0004    Contours

13-03-003-0005    Positional Accuracy

13-03-003-0001 Definition

Topographic surveys depict the planimetry and the elevation contours of a portion of the earth’s surface including natural and manmade characteristics.

The topographic survey shall be referenced to at least two (2) monumented property lines as indicated by a ROS (results of survey) per Division 13-03-002. Topography shall be shown at least twenty-five (25) feet outside of the project limits depending on the engineering design requirements. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-03-003-0002 Qualifications

All topographic surveys shall be performed by, or under the direct supervision of, a registered land surveyor (RLS) with current Arizona registration. The topographic survey shall identify the date of the survey, the surveyor, and the means by which the survey was completed. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-03-003-0003 Benchmarks

For every development, whether public or private, a series of elevation benchmarks shall be identified and/or established. Each benchmark shall be a relatively permanent object, natural or artificial, with an elevation established thereon. The elevation shall be in NAVD 88 datum with an elevation value to the nearest one-hundredth (0.01) feet.

Benchmarks for the project shall be shown on one (1) or more sheets of the construction/improvement drawings. Both the location and physical description of the monument shall be shown. Plans shall also indicate the benchmark and the elevation utilized in establishing the temporary benchmarks and elevations.

Benchmarks shall be established and shown on each site plan (at least three (3) per site) and at least every four hundred (400) linear feet on alignment plans (e.g., roads, water lines, drainage channels). (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-03-003-0004 Contours

Contour interval shall be one (1) foot or two (2) feet, depending on the slope of the ground and the judgment of the Engineer or land surveyor. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-03-003-0005 Positional Accuracy

All mapping performed by other than photogrammetric methods shall meet the NMAS with ninety percent (90%) of horizontal features at one-fortieth (1/40) of map scale, ninety percent (90%) of spot elevations with one-quarter (1/4) of the contour interval and ninety percent (90%) of the contours within one-half (1/2) of the contour interval.

Mapping performed by photogrammetric methods shall meet the ASPRS Class 1 Standards with the horizontal root mean square error (RMSE) at one-hundredth (1/100) of map scale, the spot elevation RMSE at one-sixth (1/6) of the contour interval and the contour RMSE at one-third (1/3) of the contour interval. (Ord. 2017-22, Rep&ReEn, 07/05/2017)