Increase Atchafalaya Flow to
Terrebonne
Governor’s Advisory Commission Meeting
7 August 2013
committed to our coast
committed to our coast
Master Plan Projects
Coastal Protection and Restoration Authority of Louisiana
Master Plan Assumptions
Specific Project Details
• Dredging of GIWW east of the Atchafalaya River and installation of a
bypass structure at the Bayou Boeuf Lock to increase freshwater and
sediment flows from the Atchafalaya River to Terrebonne marshes
• Modeled to maintain a minimum of 20,000 cfs east along the GIWW
towards the HNC
• Included in the 1st Implementation Period (2012-2032).
• Engineering and design, construction, and operations and maintenance
50 year budget of $299M.
• Projected to build, sustain, or maintain 13-27 square miles of land
Coastal Protection and Restoration Authority of Louisiana
AT
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FA
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Franklin
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Thibodaux
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LA F
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BAYOU SEGNETTE
Study Area Map
RC
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LAKE PALOURDE
Morgan City
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BA
U
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SC
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AF
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Lockport
Houma
C ANAL
GU LF INTR ACOASTAL WATER WAY
ATCH AFALAYA BAY
FOURLEAGUE BAY
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YO
UT
ER
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B
ON
NE
AV I GA TION
HO UM A N
LAKE DE CADE
Galliano
Montegut
Dulac
LOST LAKE
LAKE MEC HAN T
Bay Junop
Increase Atchafalaya Flow to
Terrebonne Study Area
Cocodrie
CAILLOU LAKE
TERREBONNE BAY
TE-110 Study Area [20130625]
Extended Study Area
TE-110 Study Area [20130722]
Miles
0
3
6
Ü
12
18
Projected Future Land Loss – Master Plan Moderate Scenario
AT
CH
A
FA
L
Franklin
AY
AR
IV E
Thibodaux
B AY
R
OU
LA F
OU
BAYOU SEGNETTE
Target Area Map
RC
HE
LAKE PALOURDE
Morgan City
YO
BA
U
H
SC
FE
AF
R
Lockport
Houma
C ANAL
GU LF INTR ACOASTAL WATER WAY
ATCH AFALAYA BAY
FOURLEAGUE BAY
BA
YO
UT
ER
RE
B
ON
NE
AV I GA TION
HO UM A N
LAKE DE CADE
Galliano
Montegut
Dulac
LOST LAKE
LAKE MEC HAN T
Bay Junop
Increase Atchafalaya Flow to
Terrebonne Study and Target Area
Cocodrie
CAILLOU LAKE
TERREBONNE BAY
TE-110 Study Area [20130722]
TE-110 Target Area
Miles
0
3.25
6.5
Ü
13
19.5
Project Specific Purpose and Need
• Purpose: Utilize freshwater and sediment from the Atchafalaya River in order to
build, sustain, and maintain wetlands within the Terrebonne Basin
• Objective 1:
• Distribute Atchafalaya River resources to the Terrebonne Basin in order to
increase the potential to build, sustain, and maintain wetlands
• Objective 2:
• Use material dredged from the GIWW as a component of this project to
directly create additional wetlands within the project area
• Need:
• This project is needed in order to achieve, in part, the goals of the 2012
Louisiana Coastal Master Plan and address hydrologic alterations within the
Terrebonne Basin. The lack of both freshwater and sediment inputs due to
hydrologic alterations have resulted in increased saltwater intrusion and high
subsidence rates, thus significantly contributing to wetland loss within the
Basin.
Coastal Protection and Restoration Authority of Louisiana
Project Kick Off Site Visit – May 30, 2013
• Toured:
• Bubba Dove Flood Control Structure in the Houma Navigational Canal and
potential future Houma Navigational Canal Lock site
Coastal Protection and Restoration Authority of Louisiana
Project Kick Off Site Visit – May 30, 2013
• Wetlands in the vicinity of Minor’s Canal to Marmande Ridge near Lake
Theriot, Lake Decade, Lake Penchant, and Bayou Penchant
Coastal Protection and Restoration Authority of Louisiana
DRAFT Project Schedule
• Project Kick off Meeting Held – 23 May 2013
• Data Gap Analysis Compete – September 2013
• Alternatives Formulation, Evaluation, & Comparison - Summer 2013 – Summer
2014
• Plan Selection – Summer 2014
Coastal Protection and Restoration Authority of Louisiana
Questions/Comments
Coastal Protection and Restoration Authority of Louisiana
Master Plan – Increase Atchafalaya Project
Potential Marsh Creation Component
Coastal Protection and Restoration Authority of Louisiana
Master Plan Assumptions
Specific Project Details
• Creation of approximately 1,190 acres of marsh along the GIWW in
Terrebonne Basin (through sediment dredging of the GIWW) to create
new wetland habitat, restore degraded marsh, and reduce wave erosion
• Included in the 1st Implementation Period (2012-2032).
• Engineering and design, construction, and operations and maintenance
50 year budget of $37M.
Coastal Protection and Restoration Authority of Louisiana