FLOOD00961 - Laserfiche WebLink

Home Browse Search

I I 4.5 Channel Stabilization Measures I A comparison of 100-year channel velocities between the corrected effective and post- I project condition analyses is summarized in Table 4,6, Values given in the table illustrate only minor differences between pre- and post-project conditions, Due to the relative magnitude of the indicated changes in channel velocity, no significant change in the sediment transport regime for I the reach is anticipated, I Table 4,6 Comparison of Corrected Effective and Post-Project Condition 100- Y ear Channel Velocities, I Channel Velocity Change in Channel FIRM HEC-2 (fps) Panel 1D Cross Section Corrected Post-Project Velocity I (fps) Effective Condition 16430 0,6 0,6 0,0 I BF 17380 0,6 0.4 -0,2 18075 0,5 0,5 0,0 I BG 18135 0,6 0,7 0,1 18168 0,3 0.4 0,1 18240 0,9 0,9 0,0 I BH 18625 1.5 --- --- 18770 --- 2,9 --- I BI 19337 7,3 7,5 0,2 19830 8,0 7,5 -0,5 B1 19880 6,3 6.4 0,1 I BK 20315 3,6 3,6 0,0 I The channel velocities presented in Table 4,6 do not present any significant erosion potential in the vicinity of the Centre A venue embankment, However, in accordance with FEMA I criteria, the roadway embankment has been seeded with native grass to minimize the possible deleterious effects of erosive forces, I Although the velocities shown in the table are relatively small in the vicinity of the roadway embankment, the maximum velocity through the Spring Creek and bicycle culverts is significantly higher. Results of the EXTRAN analysis for the 100-year event, post-project I condition were reviewed and evaluated to identify the most erosive condition within the Spring Creek culvert; the bicycle trail culvert was not evaluated in detail since that cell will be entirely I concrete-lined, I T:'.oPE~,rcocsrtDl \::ocsrtOl 1I;:ma-I.OMR lill:Jl-rpL\\pd 23 ANdERSON CONsulTiNG ENGiNEERS, INC.