CALCASIEU SALINITY STRUCTURES. HYDRODYNAMIC MODELING (To Support Design of Salinity Barriers)

CALCASIEU SALINITY STRUCTURES HYDRODYNAMIC MODELING (To Support Design of Salinity Barriers)

Presentation Overview 1 2 3 4 5 Project Overview and CEA Circulation Modeling Vessel Hydrodynamics Modeling Storm Surge Modeling Wave Modeling Mott MacDonald CSC (Hydrodynamic Modeling) 2 07 June 2018

Presentation Overview 1 Project Overview and CEA Mott MacDonald CSC (Hydrodynamic Modeling) 3 07 June 2018

Project Overview 1Problem: Calcasieu Basin has experienced significant land loss by saltwater intrusion into wetlands causing destruction of flora that previously stabilized the banks. 2Goal: Limit the saltwater intrusion in the Calcasieu Basin 3Solution: Construct a set of proposed construction measures to limit the exchange of saltwater from the CSC to the Calcasieu Basin. 4Path: Numerical modeling to inform the design of project features Mott MacDonald CSC (Hydrodynamic Modeling) 4 07 June 2018

Project Features Shoreline Protection Feature CSC North Features CSC South Features Basin Sills Shoreline Protection Feature Wall Structures Mott MacDonald CSC (Hydrodynamic Modeling) 5 07 June 2018

Bathymetry Development Sources Multiple Merged using a priority order Surfaces 1. Existing Conditions 2. All 14 Selected Alternatives (SA) 3. 5 Southern Selected Alternatives (SA) Priority Source Name Year Type 1 Tetra Tech 20161109_HYDRO_CS65 2016 Soundings 2 USACE CR_01_UPR CR_24_LWR 2017 Soundings 3 NOAA H11831 2011 Multibeam 4 NOAA H11830 2011 Multibeam 5 BICM wchb_2007 2006 Soundings 6 TWI (TWI, 2015) Delft-3D depth 2015 DEM 7 USACE 130627_GIWW169-191 2012 Survey Drawings 8 USGS DEM Northern Gulf 1888-2013 2014 DEM 9 NOAA Coastal Relief Model N/A DEM

Bathymetric Surface East Pass Lake Wall Alkali Ditch

Coastal Processes Analysis Conditions Wind Speed [mph]* 2020 Storm tide [ft NAVD88] 2070 Storm tide [ft NAVD88] Usual (1 yr) 35 3.6 6.3 Unusual (50 yr) 144 6.9 9.6 Extreme (100 yr) 156 8.5 11.2

Presentation Overview 2 Circulation Modeling Mott MacDonald CSC (Hydrodynamic Modeling) 9 07 June 2018

Model Setup Model Used Delft-3D Flow FM Boundary Conditions North/East/West: Time history of discharge South: Time history of wse Spatially varying manning s

Model Validation Boundary Conditions Supporting text goes here Client Supporting text goes here

Sensitivity Testing Conditions: 5-day simulation when tidal range is within top 90 th percentile. 5 and 14 Selected Alternatives. 2020 and 2070 (RSLR=2.7 ft) SA SA SA SA Scenarios Scenario 1: Low discharge Scenario 2: Average Discharge Scenario 3: High Discharge 1 yr: 1yr wind and surge Conclusions 5 vs 14; no effect on southern SA

Model Results (Max. and Median velocity) Conditions: 1 yr model run simulating 2012 boundary conditions; No RSLR; Existing, 5 & 14 Selected Alternatives Mesh SA SA SA SA

Model Results (PNE Velocity)

Presentation Overview 3 Vessel Hydrodynamics Modeling Mott MacDonald CSC (Hydrodynamic Modeling) 17 07 June 2018

Model Setup Model Used VH-LU Grid 2.2 miles X 2.7 miles 2m (6.6 ft) resolutions Design vessel Q-max Vessel Route Channel Centerline Velocities None, Peak Flood, Peak Ebb

Model Results (Velocity) PEAK EBB PEAK FLOOD

Model Results (Maximum Velocity) Peak Ebb Peak Flood SWL Maximum Velocities [ft/sec] Maximum Drawdown Magnitude [ft] Feature Peak Ebb Peak Flood SWL Peak Ebb Peak Flood SWL Joes Cut 18.3 12.1 11.1 1.9 1.4 1.3 Lake Wall (Fish Peak Pass Ebb1) 18.1 Peak 10.1 Flood 12.5 2.0 SWL 2.8 2.2 Lake Wall (South Bypass Sill) 17.8 10.3 15.8 2.3 2.5 2.2 Along Lake Wall 17.8 14.5 16.8 5.2 6.0 5.4

Presentation Overview 4 Storm Surge Modeling Mott MacDonald CSC (Hydrodynamic Modeling) 21 07 June 2018

Model Setup Model Used ADCIRC-SWAN Mesh Trimmed version of CPRA Master Plan mesh

Model Setup Storm Chosen Storm # 331 Conditions Modeled 5 SA & 14 SA meshes 2020 and 2070 50yr and 100yr storms

Model Testing Storm Storm # 331 from FEMA suite of storms Testing Criteria Water levels simulated along the Lake Wall area Point FEMA 331 MM 331 1 7.2 8.0 2 7.2 7.9 5 8.3 7.9 6 8.0 7.8 7 7.5 7.9 8 7.2 8.1 9 7.3 8.2 10 8.5 8.4 Avg. 7.6 8.0

Model Results Results Maximum surge, velocity & head difference 14 SA TSP 2020 14 SA TSP 2070 5 SA TSP 2020 5 SA TSP 2070 50-yr 100-yr 50-yr 100-yr 50-yr 100-yr 50-yr 100-yr West Pass 7.9 8.6 10.6 11.3 7.9 8.6 10.7 11.3 East Pass 7.0 7.9 10.2 10.7 6.9 7.9 10.2 10.7 Joes Cut 7.3 7.9 9.6 10.0 7.3 7.9 9.5 10.0 Lake Wall 5.9 6.4 8.6 9.1 5.9 6.3 8.6 9.1 Nine Mile Cut 7.1 8.1 10.0 10.5 7.9 8.5 10.0 10.5 Long Point Lake 5.7 6.3 8.9 9.4 5.7 6.3 8.9 9.4 Dugas Cut 2 6.0 6.8 9.5 10.0 6.0 6.8 9.5 10.0 Dugas Cut 5.7 6.4 9.1 9.7 5.6 6.4 9.1 9.6 Kelso Bayou 5.7 6.7 9.5 10.0 5.6 6.7 9.5 10.0 Texaco Cut 5.7 6.9 9.8 10.4 5.6 6.8 9.8 10.3 Alkali Ditch 4.3 5.4 9.0 9.6 4.3 5.4 9.0 9.6 Drainage Canal 3.8 5.0 8.6 9.1 3.8 5.0 8.6 9.1 Choupique Bayou 5.2 5.9 9.3 9.9 5.0 5.9 9.3 9.9

Presentation Overview 5 Wave Modeling Mott MacDonald CSC (Hydrodynamic Modeling) 26 07 June 2018

Model Setup Model Used SWAN Grid 26 miles X 18 miles Variable: 50m to 10m Testing Fetch Offshore waves Grid resolution Model Runs 14 SA 2020 & 2070 conditions 1yr, 50yr & 100yr winds & surge 16 compass directions 2070 Day-to-day conditions

Results (Example: 2070 50yr)

Results (Maximum Wave Heights) 1 yr 50 yr 100 yr

Wave Modeling (Overtopping) Modeling Approach Statistical Downscaling to generate 12 years of wave conditions Overtopping EuroTop Comparison Overtopping against Tide Induced Fluxes Calcasieu Ship Channel Salinity Control (CS-65) Draft Design Criteria Document Review 30

Modeling Results Compilation Feature Location Waves 1 Circulation 2 Hs Tp [sec] Velocity [ft/sec] [ft] Hurricane 3 Velocity [ft/sec] Hurricane 3 Head Difference [ft] West Pass Sill - - 15.0 16.4 - - Along Structure 6.1 3.6 - - 5.7 - Tie In 5.8 3.6-12.0 - - East Pass Sill - - 15.0 25.9 - - Along Structure 6.4 3.6 - - 8 - Vessel 4 Velocity [ft/sec] Tie In 5.3 3.6-15.1 - - Joes Cut Sill - - 13.8 23.4-13.6 Along Structure 7.9 4.0 - - 5.7 7.7 Tie In 5.2 4.0-10.1-6.1 Lake Wall North Bypass Sill - - 13.4 19.6 - - South Bypass Sill - - 13.1 19.9 15.6 - Fish Pass - - 9.2 20.2-13.9 Along Structure 9.4 5.6 - - 5.7 17.9 Tie In 5.5 5.6-14.3-5.9 Nine Mile Cut Sill - - 12.1 14.2 - - Along Structure 7.5 5.6 - - 4 - Tie In 5.5 5.6-14.1 - -

Numerical Modeling (to support design) Design Elements Stable stone size, Geometry Berm, Sill & Tie-Ins, Scour pads, Wave Loading and Navigability Stable Stone Size, Geometry Stone size, Berm Slope and Crest Elevation Waves Scour Design Channel side Vessel Hydrodynamics Lake Side Waves Tie-ins Storm Surge Sill Openings Storm Surge Sheet Pile Stability Loading Wave and Storm Surge Modeling Navigability Velocity through sills Circulation and Vessel Hydrodynamics Modeling.

Project Partners CPRA Tetra Tech The Water Institute Arcadis Mott MacDonald CSC (Hydrodynamic Modeling) 33 07 June 2018

Questions?

Model Validation A total of 1530 bursts were recorded, a majority of the bursts showed no significant events or unusual signals. The passage of large vessels possessed clear characteristics however: a significant drawdown of the surface elevation, as much as 1 meter (3.3 ft), as well as a corresponding flow surge at the channel edge, as much as 2 meters/second (6.6 ft/s or 4 knots) at the peak. Reference: Hydrodynamic and Sediment Transport Study. Calcasieu River and Pass, Louisiana. Dredged Material Management Plan Phase II Prepared for USACE by Applied Coastal Research and Engineering Inc.

Model Results (WSE) PEAK EBB PEAK FLOOD

Model Setup Testing Hurricane Tested RITA (2005) FEMA High Water Marks Data Higher Accuracy for points located within the lake, lower for those on marshes

Storm Surge Conditions * 10 minute averaged wind speed Condition Wind Speed [mph]* Flow Rate [cfs] Low 570 Average 4,762 High 40,608 2020 Storm tide [ft NAVD88] 2070 Storm tide [ft NAVD88] Usual (1 yr) 35 3.6 6.3 Unusual (50 yr) 144 6.9 9.6 Extreme (100 8.5 11.2 yr) 156 River Flow Datum Elevation [ft NAVD88] MHHW 1.24 MSL 0.5 MLLW -0.69 NAVD88 0