FLOOD01619

• Designation Number: 320
• County: Jefferson
• Community: Arvada
• Stream Name: Lower Ralston, Van Bibber, Leyden Creeks
• Title: Major Drainageway Planning
• Date: 2/1/1986
• Prepared For: Arvada
• Prepared By: UDFCD
• Floodplain - Doc Type: Floodplain Report/Masterplan

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IV-12

TABLE IV-2 (cont,)
FLOODPLAIN AND FLOODWAY INFORMATION
LEYDEN CREEK (cont.)

General 100-Year Floodplain 100-Year Floodway 1/2' Rise 1 DO-Year Floodway l' RI se
Cross stream lOO-Year 1 DO-Year Floodplain Floodplain F100dway Floodway Floodway* Floodway Floodway Floodway Floodway* Floodway
SectIon Thai O6g OJscharge Water Sur. Top Width Velocity Water Surf. Top WI dth Width Velocity W"ter Surf. Top Width Width Velocity
Number Sta. Eleve efs Elev. 1ft) 1ft/see) Elevation <ft) LT. RT. 1ft/see) Elevation (ft) LT. RT. (ft/see)
147502 147+30 5525.3 2,300 5528.1 450 4 5528.1 240 60 180 7 5528.3 165 60 95 7
152602 152+50 28.8 2,300 33.6 245 9 33.9 155 30 125 9 34.2 110 30 80 10
158422 158+35 34.3 2,200 40.7 245 9 40.4 135 100 35 10 40.4 125 100 25 10
168182 168+55 52.0 2,200 53.4 190 7 COINCIDENT WITH FLOODPLAIN NO ENCROACHMENT COINCIDENT WITH FLOODPLAIN NO ENCROACHMENT
171852 172+15 60.0 2,200 61.4 420 6 COINCIDENT WITH FLOODPLAIN NO ENCROACHMENT COINCIDENT WITH FLOODPLAIN NO ENCROACHMENT
175552 175+75 57.6 2,200 63.7 325 6 COINCIDENT WITH FLOODPLAIN NO ENCROACHMENT COINCIDENT WITH FLOODPLAIN NO ENCROACHMENT

* As measured from design channel centerline, looking in the downstream direction.

Note: Floodway descriptions of "1/2' Rise" and "1' Rise" represent maximum increases in the Energy Grade Line Elevation and not necessarily the water
surface elevation.