FLOOD10929

• County: Mineral
• Community: Creede
• Stream Name: Upper Willow Creek
• Basin: Rio Grande
• Title: Upper Willow Creek Watershed - FLood Control and Stream Stability Study
• Date: 10/1/2002
• Prepared For: Willow Creek Reclaimation Committee
• Prepared By: Agro Engineering
• Floodplain - Doc Type: Floodplain Report/Masterplan

LIST OF FIGURES

Figure ES.1. Locations of Potential Mitigation Projects................................................v
Figure 1.3.1. Location of Willow Creek watershed within Upper Rio Grande Basin...... ....... .1-3
Figure 1.3 .2. Watershed of Upper and Lower Willow Creek.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ......... .1-4
Figure 1.4.1. Locations of flood control problem areas............................................. ..1-5
Figure 2.1.1. Willow Creek watershed DEM topographic relief. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
Figure 2.1.2. Willow Creek watershed 40-foot elevation contours................................. .2-3

Figure 2.1.3. Survey points.............................................................................. ..2-5

Figure 2.1.4a. Aerial photo / topography, flume entrance north.................................. .2-6
Figure 2.1.4b. Aerial photo / topography, north to confluence............. ........................ ..2-6
Figure 2.1.4c. Aerial photo / topography, West Willow Creek. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2- 7
Figure 2.1.4d. Aerial photo / topography, East Willow Creek. . .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .2-8
Figure 2.2.1. Windy Gulch sub-watershed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11
Figure 2.2.2. HEC-RAS centerline, cross-sections, and hydraulic structures.................. ...2-14
Figure 2.2.3a. 100-year flood inundations, flume to XS 15....................................... ...2-18
Figure 2.2.3b. 100-year flood inundations, XS 15 to confluence................................. ...2-19
Figure 2.2.3c. 100-year flood inundations, West Willow Creek. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... .2-20
Figure 2.2.3d. 100-year flood inundations, East Willow Creek.................................. ...2-21
Figure 2.2.5. Earthen / wooden dam................................ .......................... ...2-22
Figure 2.2.6. Wooden weir at east end......................................................... .2-22
Figure 2.2.4. Flood inundations, flume to XS 15............................................ ...2-23
Figure 2.2.7. Flood elevations at weir.............................................................. ....2-24
Figure 2.2.8. Path of weir overbank flooding........................................................ .2-24
Figure 2.2.9. Timber drop at cross section 9........................................................ ..2-24
Figure 2.2.10. Timber drop at cross section 6...................................................... ...2-24
Figure 2.2. 11 . Pond at X S 6. 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 25
Figure 2.2.12. Low point in road and fire department tunnel.................................... ....2-25
Figure 2.2.13. Overtopping of Windy Gulch culvert cross section...... .. .. .. .. .. .. .. .. .. .. .. .. .. .2- 26
Figure 2.2.14. Flooding caused by Windy Gulch culvert......................................... ...2-26
Figure 2.2.15. Flood levels in Army Corps flume forebay........................................ ..2-27
Figure 2.2.16. North Creede Culvert.................................................................. .2-28
Figure 2.2.1 7. Flood elevations at XS 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-28
Figure 2.2.18. Slope transition and debris in culvert.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .2-28
Figure 2.2.19. Flooding inundations caused by North Creede culvert........................ ... ..2-29
Figure 2.2.20. HEC-RAS analysis of bridge.................................................. ..... .2-30
Figure 2.2.21. Erosion downstream of bridge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .2- 30
Figure 2.2.22. West Willow culvert................................................................. ...2-30
Figure 2.2.23. Flood elevations at culvert........................................................... ..2-30
Figure 2.2.24. Flood path at West Willow Culvert............................................... ....2-31
Figure 2.2.25. Commodore tailings pile.............................................................. .2-32
Figure 2.2.26. Entrance to flume....................................................................... .2- 32
Figure 2.2.27 . Wooden section of flume. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . .2- 32
Figure 2.2.28. Drop from flume to middle level of tailings pile........................... ........ .2-32
Figure 2.2.29. Entrance to Commodore pipe........................................................ ..2-33
Figure 2.2.30. Drop from Commodore pipe........................................................ ...2-33