Increase Atchafalaya Flow to TerrebonneGovernor’s Advisory Commission Meeting7 August 2013

committed to our coastcommitted to our coast

Coastal Protection and Restoration Authority of Louisiana

Master Plan Projects

Coastal Protection and Restoration Authority of Louisiana

• 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

Master Plan AssumptionsSpecific Project Details

Study Area Map

FOURLEAGUE BAY

CAILLOU LAKE

LAKE PALOURDE

LAKE DE CADE

Bay JunopCocodrie

Dulac

Montegut

Thibodaux

Lockport

LOST LAKE

TERREBONNE BAY

Houma

Galliano

Franklin

Morgan City

GU LF INTR ACOASTAL WATER WAY

ATCHAFALAYA RIVE R

BAYOU LAFOURC HE

BAY

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TE

RR

EB

ON

NE

ATCH AFALAYA BAY

LAKE MEC HAN T

BA

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U S

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TT

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A N

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JAW

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BAYOU SCHAFFER

Increase Atchafalaya Flow to Terrebonne Study Area

TE-110 Study Area [20130625]

Extended Study Area

TE-110 Study Area [20130722]

Projected Future Land Loss – Master Plan Moderate Scenario

Target Area Map

FOURLEAGUE BAY

CAILLOU LAKE

LAKE PALOURDE

LAKE DE CADE

Bay JunopCocodrie

Dulac

Montegut

Thibodaux

Lockport

LOST LAKE

TERREBONNE BAY

Houma

Galliano

Franklin

Morgan City

GU LF INTR ACOASTAL WATER WAY

ATCHAFALAYA RIVE R

BAYOU LAFOURC HE

BAY

OU

TE

RR

EB

ON

NE

ATCH AFALAYA BAY

LAKE MEC HAN T

BA

YO

U S

EG

NE

TT

E

HO

UM

A N

AV

IGA

TIO

N C

AN

AL

THE

JAW

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BAYOU SCHAFFER

Increase Atchafalaya Flow to Terrebonne Study and Target Area

TE-110 Study Area [20130722]

TE-110 Target Area

Coastal Protection and Restoration Authority of Louisiana

• 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.

Project Specific Purpose and Need

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

• 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

DRAFT Project Schedule

Coastal Protection and Restoration Authority of Louisiana

Questions/Comments

Coastal Protection and Restoration Authority of Louisiana

Master Plan – Increase Atchafalaya ProjectPotential Marsh Creation Component

Coastal Protection and Restoration Authority of Louisiana

• 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.

Master Plan AssumptionsSpecific Project Details