Land Building Sediment Diversion at Myrtle Grove: Evolution & Status Update Brian Vosburg Geologist...
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Transcript of Land Building Sediment Diversion at Myrtle Grove: Evolution & Status Update Brian Vosburg Geologist...
Land Building Sediment Diversion at Myrtle Grove: Evolution & Status Update
Brian VosburgGeologistGovernor’s Advisory Commission MeetingAugust 1 2012
committed to our coastcommitted to our coast
Coastal Protection and Restoration Authority of Louisiana
• Re-cap of State/EDF Joint Myrtle Grove Investigation
• LCA Myrtle Grove Feasibility Study Status Update
• 2012 State Master Plan and the Myrtle Grove Diversion
• State Led Myrtle Grove/Mid-Barataria Diversion Engineering, Design and Permit Application Effort Overview
Presentation Overview
Coastal Protection and Restoration Authority of Louisiana
• Joint venture between CPRA & Environmental Defense Fund intended to provide the LCA Feasibility Study with robust decision making tools in the form of numerical hydrodynamic models based on site specific observational data
• Included site specific river data collection, riverside hydrodynamic modeling, and bayside hydrodynamic and land building modeling
• Seven Data collection events (2008-2011) at river discharges of 300,000 – 1,100,000 cfs
• Multi-dimensional river modeling of an array of diversion sizes, locations and alignments to identify optimal intake location and diversion configuration
• Bayside hydrodynamic modeling of water levels and velocities to evaluate impacts of different discharges and operating regimes
State/EDF Joint Myrtle Grove Investigation
MYRTLEGROVE
WATER DISCHARGE
P-6/63 Point Integrative Isokinetic Sampler
Spatial Trends(Bar Position)
Mg4 Mg3 Mg2b Mg2
May 15
May 14
May 13
May 12
May 11ADCP
Bar (sand) Resuspension
May 2010
662.8K cfs
726.4K cfs
Lateral Bar Face Suspended-Bedload
Cycle
THAL
WEG
LATERAL BAR
Bedf
orm
s
RH
Water Vel.
Water Vel.
Water Vel.
Myrtle Grove Diversion
FLOW-3D Model Domain
Coastal Protection and Restoration Authority of Louisiana
• FCSA executed and Study initiated May 2010- √
• Develop and Screen Initial Measures August 2011 - √
• Hydrodynamic Modeling (Barataria Bay water level and salinity) February 2013*
• Identify Tentatively Selected Plan May 2013
• Chief’s Report signed October 2014
LCA Myrtle Grove Feasibility Study
Coastal Protection and Restoration Authority of Louisiana
• Identified 8 Diversion Projects, including one in the vicinity of Myrtle Grove-
• “Mid-Barataria Sediment Diversion”• 50,000-250,000 cfs sediment diversion in the vicinity of Myrtle
Grove intended to maintain existing land and build new land• Two phases- initial 50,000 cfs magnitude, then increase to larger
250,000 cfs magnitude sometime in the future
2012 State Master Plan & Myrtle Grove
Keystone of the 2012 Master Plan: Reconnecting the River
Flow regimes of sediment diversions based on flow in river. Large-scale diversions (250,000 cfs) operate at full capacity for short periods of time (typically less than a
month) and in some years, are not operated at all at full capacity.
Uses up to 50% of the Mississippi River’s peak flow.
Coastal Protection and Restoration Authority of Louisiana
• The State is currently in the process of seeking a Contracting Firm that will manage the complete process of engineering and design, environmental compliance, and permit application for a ~50,000 cfs magnitude Diversion in the vicinity of Myrtle Grove. (Mid-Barataria Sediment Diversion)
State Led Engineering, Design and Permit Effort
Coastal Protection and Restoration Authority of Louisiana
• A sediment diversion at this location is a top priority for the State.
• The LCA Myrtle Grove Study will continue, and will communicate and coordinate with this effort.
• Provides a Parallel Path for the LCA Myrtle Grove Diversion and the State Master Plan Mid-Barataria Diversion.
• Goal is to ensure that the State is well prepared to act should sufficient funding become available to implement the project, particularly if the funding becomes available relatively soon.
• The “parallel path” approach will best position the State to implement this important project should funding become available from any source.
State Led Engineering, Design and Permit Effort
Coastal Protection and Restoration Authority of Louisiana
• Key Milestone Dates (tentative)
• Mid-August 2012 – Selection of Contracting Firm
• Mid-October 2012 – Issuance of NTP
• Mid-October 2013 – Submittal of Permit Application
• Mid-April 2014 – Submittal of Final Design with bid Documents
State Led Engineering, Design and Permit Effort