FLOOD10335 ‎(2)‎

• Designation Number: 589
• County: Adams
• Community: Adams County
• Stream Name: Clear Creek
• Title: FHAD - Clear Creek ‎(Adams County)‎
• Date: 12/1/2005
• Prepared For: Adams County, CDOT, UDFCD
• Prepared By: Ayres Associates
• Floodplain - Doc Type: Floodplain Report/Masterplan

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Table of Contents
Paae No.
PREFACE ................................. ......... 1
Authorization ................................. ......... 1
Purpose and Scope ................................. ......... 1
Mapping ................. ................................. ......... 1
Acknowledgements ................................. ......... 1
STUDY AREA DESCRIPTION ................................. ......... 1
FLOOD HiSTORy................... ................................. ......... 3
FLOOD RELATED STUDIES.. ................................. ......... 3
HYDROLOGIC AND HYDRAULIC DETERMINATIONS ............. .........' 3
Hydrologic Analysis................................................................ ........., 3
Hydraulic Analysis.................................................................. .........' 3
FUTURE FLOODS.......... ............. .... ......... ... .... ....... ............... ..... ........., 3
Flood Frequency and Discharge............................................. .........' 3
Flooded Areas........................................................................ ........., 4
South Platte to York Street................................................ .........' 4
York Street to 1-25................... ........... ............ .................... .........' 4
1-25 to Federal Boulevard .................................................. ........., 4
Federal Boulevard to Sheridan Boulevard.......................... .........' 4
Flood Velocities...................................................................... ........., 5
SUMMARy.... ........... ......... ... ... .... ... .......... .............. ... ............. .... ........., 5
REF E R ENC ES ........................................................................... .........' 5
List of Appendices
Appendix A Photographs
Appendix B Discharge Profile; Floodplain and Floodway Data Tables
Appendix C Flood Hazard Area Delineation Plan View Index Map and Sheets; Profile Sheets
List of Tables
Paae No.
Table 1: Floodplain and Floodway Data Table for Clear Creek Main Reach..... 18
Table 2: Floodplain and Floodway Data Table for Clear Creek North Overflow 23

Figure 1. Basin Boundary Map ............................................................................
Figure 2. Grouted Boulder Drop Structure at d/s boundary of reach Looking SW
Figure 3. Pedestrian Bridge at d/s boundary of reach Looking W..................................
Figure 4. Grouted Boulder Drop at gage station, located at Clear Creek Station 19+64
Figure 5. York Street Bridge Looking d/s......................................................................
Figure 6. 1-270 Bridge Looking u/s ................................................................................
Figure 7. Grouted Boulder Drop Structure u/s of 1-270 Looking S.................................
Figure 8. Deposition d/s of Grouted Boulder Drop structure u/s of 1-270........................
Figure 9. Grouted Boulder Drop at Clear Creek River Station 72+03 Looking S...........
Figure 10. Grouted Boulder Drop at Clear Creek River Station 77+53 Looking S.........
Figure 11. Washington Street Bridge Looking u/s..........................................................
Figure 12. First (furthest downstream) Crossing of 1-25 Looking d/s..............................
Figure 13. Grouted Boulder Drop Between 1 st and 2nd Crossings of 1-25 Looking SW.
Figure 14. Second Crossing of 1-25 Looking u/s.....................................................
Figure 15. Between 2nd and 3rd Crossings of 1-25 Looking S................................
Figure 16. Between 4th and 5th Crossings of 1-25 Looking S .................................
Figure 17. Grouted Boulder Drop Structure at 5th Crossing of 1-25 Looking SE .....
Figure 18. Sixth (furthest upstream) Crossing of 1-25 Looking u/s ..........................
Figure 19. Grouted Boulder Drop Structure u/s of 6th 1-25 Crossing.......................
Figure 20. Broadway Bridge Looking d/s ................................................................
Figure 21. Outlet Gates of Diversion Dam Looking u/s...........................................
Figure 22. Pecos Street Bridge Looking SE ...........................................................
Figure 23. U/S face of Colorado & Southern Railroad Bridge Looking SE ..............
Figure 24. Drop Structure 25 ft d/s of Colorado & Southern RR at station 202+00
Figure 25. Little Dry Creek Outlet Structure to Clear Creek .................................
Figure 26. Low water crossing at Station 215+50 Looking S (Not Modeled) ........
Figure 27. U/S face of Federal Boulevard bridge Looking d/s..............................
Figure 28. U/S face of Rio Grande RR Bridge Looking E ....................................
Figure 29. East Crossing of 1-76 Looking W between bridges .............................
Figure 30. UlS face of Lowell Boulevard. bridge Looking NE...............................
Figure 31. Rock drop at u/s face of Lowell Boulevard bridge Looking N ..............
Figure 32. Diversion Dam at d/s face of Lowell Boulevard bridge Looking N .......
Figure 33. D/S face of Tennyson Street bridge Looking S ...................................
Figure 34. Diversion at Left Bank, d/s face of Tennyson Street bridge Looking N
Figure 35. West crossing of 1-76 Looking NW ..................
Figure 36. D/S face of Sheridan St bridge Looking N
Figure 37: Flow Discharge Profile............

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AWES
AS2CC;i~:'ES

list of Figures

Paae No.

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