HomeMy WebLinkAboutCOW 2015-09-28 Item 2 - Presentation - Briscoe-Desimone LeveeBriscoe- Desimone Levee Improvements
Tukwila City Council
September 28, 2015
Alan-
KING COU\TY
FLOOD CONTROL
1) 1 FL 1
4se
KENT
N)
"' Green River Levees were built in the 1960's
Billions have been invested in the Green River Valley since the Howard Hanson Dam and
Green River Valley Flood Issues
• FEMA Flood Hazard Maps
• Weakened Howard Hanson
Dam
• NMFS Biological Opinion
00
2010 - Preliminary
Digital Flood
Insurance Rate
Map
Howard Hanson Dam
ink
Howard Hanson Dam
Colonel Wright
W January 2009
Inundation Area From Briscoe /Desimone Levee Failure
Briscoe - Desimone Levee
System
Repair Reach 1:
Wall installation
Completed
Summer 2015
Repair Reach 2:
Completed
Fall 2014
Repair Reach 3:
Completed
Fall 2014
Repair Reach 4:
Under Construction
N)
Briscoe /Desimone Levee
IN)
Existing River Bank
Existing Riverbed
Proposed
Paved Trail
Proposed Levee Fill
Proposed Sheet Pile Wall
Existing
Building
N
W
N)
Sheet Piles for Flood Wall Construction
O)
Sheet Pile Installation
Sheet Pile Flood Wall
Briscoe - Desimone Levee Improvements North End
of Reach 1 looking upstream
BEFORE
AFTER
(A)
IN)
Briscoe - Desimone Levee Improvements Southerly End
of Reach 2 looking upstream
BEFORE
AFTER
Briscoe - Desimone Levee Improvements
Reach 3 Parking lot ramp on the left side
BEFORE
AFTER
100 -Year Flood Elevation
Levee
Access Road
Top Soil and Grass
Grass
Fabric Wrapped Fill
Riprap
Launchable Toe
Ordinary High o
Water Level 0 0 a
° o0 0
0 °0 o ° 0 o
0 00 0 °
0h
L Oo.0a,
iver Channe
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/f°
0vc 0
0 o
Al a0oa
0 °°u
0a
O
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ROCK STABILIZED SETBACK LEVEE
Corps of Engineers' Construction on Reach 1
Corps of Engineers' Construction on Reach 1