FLOOD01607

• County: Gilpin
• Community: Central City
• Stream Name: Eureka and Nevada Gulches
• Title: Master Drainage Study
• Date: 2/12/1988
• Prepared For: Central City
• Prepared By: HydroDynamics
• Floodplain - Doc Type: Floodplain Report/Masterplan

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TABLE OF CONTENTS

Page

EXECUTIVE SUMMARY

ACKNOWLEDGMENTS

SECTION 1.
1.1
1.2
1.3

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .,. .1
Purpose and Scope................................ 2
Location and Site Characteristics................2
Previous Studies and Information Used in Report..4

SECTION 2. DRAINAGE HISTORy..................................... 5

SECTION 3. HYROLOGY AND HyDRAULICS..................... .........8

3. 1 Gener a 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
3.1.1 Eureka Gulch................................9
3.1.2 Nevada Gulch................................ 9
3.2 Reservoir Routing................................10
3.3 Hydraulics...................................... .12

SECTION 4. EUREKA GULCH DRAINAGE................................15

4.1 General. . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
4.1.1 Major Drainage............................. .16
4.1.2 Local Drainage..............................21
4.2 Dorothy Lee Placer Detention Facility............22
4.3 Opera House Flume Inlet Improvements.............22
4.4 Other Eureka Gulch Locations.....................23
4.4.1 Gregory Gulch/Lawrence Street Cribbing......23
4.4.2 MacFarlane Foundry Flume....................23
4.4.3 Prosser Loop Pipes..........................23
4.4.4 Rehabilitate Opera House Flume..............23
4.4.5 Tree and Debris Removal.....................23
4.4.6 Prosser Loop Pond {Lion's Park).............24

SECTION 5. NEVADA GULCH DRAINAGE......................,.........25

5.1 General. .. . . .'. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
5.1.1 Existing Drainage Facilities................26
5.1.2 Proposed Drainage Facilities................26
5.2 Nevada Gulch Flume Inlet Improvement.............27
5.3 Spring, Roworth and Nevada Street Inlets.........27
5.4 Mine Tailing and Slope Stabilization.............27
5.5 Maintenance Practices............................28

SECTION 6.
6.1
6.2

COST ESTIMATES...................................... .29
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Cost Estimate Summary............................30

SECTION 7. ECONOMIC ANALySIS.................................... 31