FLOOD10417

• County: Mineral
• Community: Mineral County
• Stream Name: Willow Creek
• Title: Willow Creek Channel Improvement, Mineral County, Colorado - Channel Replacement Feasibility Report
• Date: 8/13/2003
• Prepared For: Willow Creek Reclaimation Committee
• Prepared By: Chou Cha, P.E., Civil Engineer
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

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TABLE OF CONTENTS

TAB LE 0 F CONTENTS ................. ......................................... ........ .............. .............................................. I

LIS T 0 F FIGURE S ....... .................................. ........................... ...................... .............. ...... ...... ................. II

LIST 0 F TABLE S ............................. ................... ......................... ........................ ........................... ........... II

ACKNOWLEDGEMENT S ................. ................. ..................... ............................... .............. ......... ............ II

EXECUTIVE SUMMARy..................... ............. ................. ................................... ................. .........."...... III

1. INTR 0 D U C TI ON.......... ....... ................ ............... ............. ............................. ...... ............... ......... ............ ][

2 . PROJECT LOCATION ........ ................. ............... ................. ................. .......... ................... ......... ."........ ][

3 . BACKGROUND.... ............................ ............... ........... ..................... ................... ............ ......... ........'........ ][

4 . REPLACEMENT 0 PTI 0 N ................ ............. ............. ....................... ................ ........... ........... .....'........ ..

5. DEMOLITION ............ .......... ................. ............. ......... ......................... ............... ............ ....................... 5

6. DE SIGN AL TERN A TIVE S. ..................... ........... ............... ..................................... ............. .......... ........ 5

6.1 ALTERNATIVE 1- EXISTING CHANNEL SHAPE ......................................................................... 6
6.2 ALTERNATIVE 2 - RECTANGULAR CHANNEL SHAPE............................................................. 7
6.3 ALTERNATIVE 3 - PARTIALLY FULL FLOWING PIPE .............................................................. 8
6.4 ALTERNATIVE 4 - PARTIALLY FULL FLOWING CONCRETE BOX CULVERT..................... 9

7 . APPURTENANCE STR U CTURES..................................................................................................... 1 (I

7.1 TRAFFIC GUARDRAILS ................................................................................................................. 10

7.2 PEDESTRIAN BRIDGES .................................................................................................................. 10

7.3 SAFETY CABLES............................................................................................................................. 11

7.4 STILLING BASIN STRUCTURE ..................................................................................................... 12

8. DESIGN AND CONSTRUCTION ELEMENTS................................................................................ 12

8.1 DESIGN DATA A.CQUISITION ....................................................................................................... 12

8.1.1 SUR VEY DA TA COLLECTION....... ............. ............... ............. ........ .................... ........... ......... ... 13
8.1.2 GEOTECHNICAL DA TA COLLECTION.................................................................................... 13
8.1.3 DESIGN DATA COLLECTION COSTS ......................................................................................13
8.2 CONSTRUCTION DRAWINGS, SPECIFICATION, AND DESIGN SUMMARy........................ 14
8.3 CONSTRUCTION PERMITS AND ENVIRONMENT ASSESSMENT.......................................... 14

8.4 CONSTRUCTION .............. ............................................................................................................... 14-
8.5 NRCS STAFF DAYS REQUIREMENT............................................................................................14-

8.5.1 DESIGN DATA COLLECTION............. ..... ........ ....................... .... ....................... ........... ............ 14
8.5.2 CONSTRUCTION DRAWING DESIGN AND PRODUCTION............................................."..... 15
8.5.3 CONSTRUCTION SPECIFICATION, ENGINEERING ESTIMATE, AND DESIGN SUMMARY

........................................................................................................................................................,.....15
8.5.4 CONSTRUCTION OVERSIGHT AND SUBMITAL REVIEWS .................................................. 15
8.6 FINAL DESIGN AND CONSTRUCTION SCHEDULE.................................................................. 17
8.6.1 CONSTRUCTION SCHEDULE CONSIDERATION..................................................................17

9. CON CL USI ON...................... ................... ............. ................. ......................................... ........... ............ 18

REFERENCES ... ...... ..................................... ................................. ........................................... ...........'...... 21

NRCS Northern Plains Engineering Team I