herbert hoover dike rehabilitation project herbert ... - City of South Bay

HERBERT HOOVER DIKE REHABILITATION PROJECT Project Update for the City Commission of South Bay Ingrid Bon, P.E. U.S. Army Corps of Engineers Jacksonville District September 2015

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Presentation Outline
Overview
Problems
System-Wide Reduction Approach
Dam Safety Modification Study
Reach 1 Rehabilitation
Culvert Replacement Program
Rehabilitation Progress

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Herbert Hoover Dike Overview
Lake Okeechobee is approximately 720 square miles
Basin is over 5,600 square miles
Average water depth is 9 feet
One foot of rainfall runoff from the basin can result in a three to four foot rise of the lake
During large flood events, water can flow into the lake much faster than it can be released Lake Okeechobee

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Congress Authorizes Herbert Hoover Dike in 1930


Over 3,000 lives were lost by the 1926 and 1928 hurricanes
Significant economic impacts
HHD first authorized in 1930
Multiple authorizations

North Shore - 16 miles South Shore - 68 miles

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Herbert Hoover Dike Today 143 miles of embankment around Lake Okeechobee








32 federal culverts 5 spillway inlets 5 spillway outlets 9 navigation locks 9 pump stations

No overflow capability Built by hydraulic dredge and fill methods


Not acceptable to today’s construction standards

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HHD Problems (Failure Modes) Internal erosion (seepage and piping)

Piping


Through embankment
Through foundation

Culvert structures
Soil erosion into conduit

Sinkhole


Erosion/Piping around conduit

Overwash/Overtopping
Erosion of downstream slope

Dam Safety Action Classification (DSAC) Level 1- Assigned 2006

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Culvert deterioration

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Herbert Hoover Dike Solutions Major Rehabilitation Report (MRR) 2000


Reach 1 initial phase




Cut-off wall constructed

Federal Water Control Structure Culverts 2011


32 Federal culverts within the entire HHD system




Replacement or removal

Dam Safety Modification Study (DSMS) 2016

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System-wide approach




Risk reduction measures below tolerable guidelines




Prioritize implementation

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Dam Safety Modification Study OKEECHOBEE

Risk Assessment – Analysis performed on 32 segments within the 7 common inundation zones to identify and prioritize remediation

Modification Report – Tentatively Selected Plan is scheduled to be finalized in Fall 2015 with final report approval by Summer 2016

BUCKHEAD RIDGE

BRIGHTON SEMINOLE INDIAN RESERVATION

Fisheating Creek

LAKEPORT

LAKE OKEECHOBEE

PORT MAYACA

PAHOKEE

MOORE HAVEN Calooshatchee River

CLEWISTON

Impact – Recommend and

LAKE HARBOR SOUTH BAY

approve the final risk reduction measures needed for the entire system with implementation starting in 2019.

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BELLE GLADE

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HHD Reach 1 Rehabilitation Approval from 2000 HHD Major Rehabilitation Report Completed – 21.4 miles of cutoff wall installed between 2007 and 2013 Planned – Cutoff wall tie-ins to 3 existing structures and 1 bridge with contract award in FY16 Complete the continuous seepage barrier through Reach 1 providing the risk reduction benefits to the adjacent communities

Reach 1 Cutoff Wall Status Cutoff Wall Installation Complete Cutoff Wall Gap Closures Planned

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Reach 1 Cutoff Wall Extension Approval from 2015 HHD Major Rehabilitation Report Supplement Planned – 6.6 miles of cutoff wall installed with contract award in FY17 and completion in 2020 Impact – Final embankment remediation project to complete repairs reducing risks to inundation Zone A

Cutoff Wall Extension

Complete the continuous seepage barrier through Inundation Zone A providing the risk reduction benefits to the adjacent communities and allow a recommendation for accreditation to FEMA for this area of HHD

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HHD Culvert Replacement Program Approval from 2011 HHD Culvert Letter Report Completed – 1 removal and 2 replacements Ongoing – 8 contracts with 16 replacements completed by 2020 Planned – 7 contracts with 10 replacements completed by 2022 Complete repairs at the highest points of failure through the HHD system Note: 3 abandonments may be combined with fixes from the DSMS and are not currently scheduled Water Control Structure (Culvert ) Status Construction Contract Complete Construction Contract Ongoing Construction Contract Planned

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KI-2

Water Control Structure (Culvert) Replacements - Construction Contract Awards

C-8 KI-1

C-6

KEY

IP-3 IP-2 HP-5 HP-3

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FY 2011

2

FY 2012

6

FY 2013

2

FY 2014

3

FY 2015

4

FY 2016

3

FY 2017

2

FY 2018

IP-1 HP-6

HP-2 HP-1 C-11 C-16 C-5

C-10A C-13

C-5A C-1 C-1A C-10 C-2

C-12A C-12 C-3 C-4A

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BUILDING STRONG S-269 (C-11) ®

BUILDING STRONG S-270 (C-16) ®

BUILDING STRONG S-272 (C-13) ®

BUILDING STRONG S-273 (C-10) ®

BUILDING STRONG S-275 (C-12) ®

BUILDING STRONG S-276 (C-4A) ®

BUILDING STRONG S-277 (C-3) ®

BUILDING STRONG S-278 (C-2) ®

BUILDING STRONG S-279 (C-1A) ®

BUILDING STRONG S-280 (C-1) ®

BUILDING STRONG S-281 (C-5A) ®

BUILDING STRONG S-287 (HP-2) ®

Questions?

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