Laserfiche WebLink
CONDITIONAL LETTER OF MAP REVISION (CLOMR) <br />FOR <br />ST. VRAIN LAKES <br />Page 5 <br />Downstream of I-25 Frontage Road Upstream of Interstate 25 Bridge <br />Bridge Cross-Section 70610 <br />Downstream of the I-25 bridge and I-25 frontage road bridge exists a riprap <br />• rundown for energy dissipation due to the effects of the bridge. This structure <br />can be seen in Photo No. 1. Carroll & Lange, Inc. surveyed this structure and <br />has included it in the model at cross-sections 71735 - 71608. The bridge at <br />Weld County Road 13 has been improved since the ACOE study and a field <br />survey was also performed on the bridge and updated in the model. <br />Photo #3 <br />New bridge at Weld County Road 13 <br />and St. Vrain River, constructed 2004. <br />Cross-Section 56400 <br />Ineffective flow areas were designated and incorporated into the model upstream <br />and downstream of the bridges at I-25 and WCR13. A contraction ratio of 1:1 <br />was utilized upstream of the WCR13 bridge and an expansion ration of 1.5:1 was <br />utilized downstream of the bridges. These ineffective flow areas are shown on <br />the work maps. <br />n <br />U <br />Photo No. 1 Photo No. 2 <br />