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

Figure 2.2.31. Nelson adit, Parshall flume, and mine drainage.....................................2-33
Figure 2.2.32. Three-dimensional view of Commodore Mine and 100-year flood level....... .2-34
Figure 2.2.33. Flood Inundations on Commodore Tailings Piles................................. ..2-35
Figure 2.2.34. Entrance to Amethyst culvert........................................................ ..2-36
Figure 2.2.35. Flood elevations at entrance to Amethyst mine culvert........................... .2-36
Figure 2.2.36. Culvert above cross section 40..................................................... ....2-36
Figure 2.3 .1. Watershed physical characteristics.................................................... .2- 38
Figure 2.3.2. Primary Watershed Sediment Sources... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-40
Figure 2.3.3. Watershed sediment production potential rating.................................... ..2-42
Figure 2.4.1. Elevation profiles by main channel distance in feet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-44
Figure 2.4.2. Potential bedload transport rates for various flood return intervals............... .2-47
Figure 2.4.3. Sediment volumes produced by single flood events................................ .2-49
Figure 2.4.4. Cumulative sediment volumes for years without maintenance.................... .2-49
Figure 2.4.5 . Debris at flume mouth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2- 50
F i gur e 2.4. 6 . Deb ri s near X S 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2- 5 0
F i gur e 2.4. 7 . Deb ri s near X S 2 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2- 5 0
Figure 2.4.8. Sediment source near XS29.............................................................2-50
Figure 2.4.9. Timber debris near XS33.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .2-51
Figure 2.4.10. Timber debris near XS31............................................................ ...2-51
Figure 2.4.11. Sediment deposition above Commodore flume.....................................2-51
Figure 2.4.12. Wooden stave water pipe above XSE 15.. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 2-51
Figure 3.1.1. Locations of Potential Mitigation Projects........ .... ............................... ....3-1
Figure 3.2.1. Windy Gulch 57cfs box culvert plan view............... .............................. ..3-4
Figure 3.2.2. Roadway centerline plan view of Windy Gulch flood overflow.....................3-5
Figure 3.2.3. Water surface elevations at US section of Windy Gulch box culvert I pan...... ...3-5
Figure 3.3.1. Widening of XS 14 weir... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9
Figure 3.3.2. HEC-RAS analysis of widened XS14 weir............................................ .3-9
Figure 3.3.3. Overall plan view ofXS1 to XS15 stream restoration............................. ..3-11
Figure 3.3.4. Plan view north end of stream restoration............................................ .3-12
Figure 3.3.5. Flood levels over combination weir looking D/S................ .................. ...3-12
Figure 3.3.6. Plan view of mid section and south end of stream restoration............ ...........3-14
Figure 3.4.1. North Creede culvert replacement options, 5-50yr and 1 OOyr..................... ..3-18
Figure 3.4.2. Plan view of North Creede footbridge............................................... ..3-19
Figure 3.5.1. Plan View of Commodore pipe alternative.......................................... ..3-23
Figure 3.5.2. Plan view of Commodore flood bypass "preliminary" design. . . . . . . . . . . . . . . . . . . . . .3 - 25
Figure 3.5.3. Average monthly streamflow in West Willow Creek................................3-27
Figure 3.5.4. Flow duration curve and potential power generation at Commodore............ ..3-28
Figure 3.6.1. Plan view of proposed gratings above Commodore flume entrance.............. .3-30
Figure 3.6.2. Profile view of second proposed grating above Commodore flume entrance... .3-30
Figure 3.7.1. Plan and profile views of Amethyst debris control structure............ ........... ..3-31
Figure 3.8.1. Timber debris locations within study area.......................................... ...3-34
Figure 3.9.1. Restoration of access road below Commodore mine.............................. ...3-35
Figure 3.10.1. Plan view of West Willow bridge bank protection................................. 3-37
Figure 3.11.1. Photo of natural vortex weir looking upstream................................... ....3-39
Figure 3.12.1. High priority locations for sediment source controls.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .3 -41