Laserfiche WebLink
<br />. etegory . <br /> Ploodplain Valley I Category Category III <br />, gradient in per- t-1aximum allowable Maximum allowable Maximum Allowable <br /> cent (%) mapping SealeY mapping scale.!/ mapping scale y <br /> 0-0.5 1" = 900' 1" = 1000' 1" = 1000' <br /> 0.51 - 1.0 1" = 500' 1" = 660 1" = 1000' <br /> 1. 01 - 1.5 1" = 300' 1" = 500' 1" = 1000' <br /> 1. 51 - 2.0 1" = 200' 1" = 400' 1" = 660' <br /> 2.01 - 3.0 1" = 150' 1" = 200' 1" = 400' <br /> 3.01 - 4.0 1" = 100' 1" = 200' 1" = 400' <br /> 4.01 N.A. 1" = 100' 1" = 200' <br /> <br />II Maps meeting National Map Accuracy Standards for the noted scale <br />or any accurate enlargement therefrom. <br /> <br />~ Minimum horizontal control requirements for all cross-section <br />lines. <br /> <br />I) Location co-ordinates for one endpoint and a bearing or <br />location coordinates for two end points. <br /> <br />II) Permanent monuments with coordinates not more than ~ mile <br />apart along the study reach. <br />+.. h." P '...(>.........0 .for +'-'e. s -N <ly, i:,k <br />If photogrammetric mapping is ~ type of plotting instrument, <br />the "c" factor, the camera focal length and the vertical and horizontal <br /> <br />control used for compilation shall be described in the technical adden- <br /> <br />dum. All vertical and horizontal control surveys for photogrammetric <br /> <br />mapping, monumentation and cross-section location surveys shall be <br /> <br />at 3rd order accuracy. <br /> <br />Cross sections by field surveys or photogrammetric methods <br /> <br />shall meet the following vertical tolerances as related to true elevation. <br /> <br />All points within I 0.5 foot <br /> <br />90% of the points within 0.4 foot <br /> <br />70% of the points within 0.25 foot <br /> <br />The horizontal position of the cross section points shall be <br /> <br />referenced in a manner so their location can be re-established. <br /> <br />The alignment of all cross sections used in the study shall <br /> <br />6ho..-YVJ <br />be^on the floodplain map. <br /> <br />Dimensions of all hydraulic structures along the stream shall <br /> <br />be obtained from available sources and field checked, or by direct <br /> <br />-2- <br />