U.S. ARMY CORPS OF ENGINEERS – NEW ORLEANS DISTRICT

7400 LEAKE AVENUE, NEW ORLEANS, LA 70118

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LOUISIANA COASTAL PROTECTION AND RESTORATION AUTHORITY

450 LAUREL STREET, BATON ROUGE, LA 70808

http://coastal.louisiana.gov

Mississippi River Hydrodynamic 

and Delta Management Study

Data Collection 

Team Leaders: Mead Allison, the Water Institute of the Gulf (CPRA), Thad Pratt Engineer Research and 

Development Center (USACE)

Team Participants: Coastal Protection and Restoration Authority of Louisiana, US Geologic Survey, USACE 

Engineer Research and Development Center, USACE Mississippi Valley District 

Purpose: Data management and collection will compile and analyze existing data and conduct field observational 

studies of water and sediment dynamics to supplement existing data sets as needed. This effort will enable 

researchers to characterize existing conditions and processes. Observational data will also support the development 

of numerical models that are capable of simulating the complex behavior of water, sediment, nutrients, and salinity. 

These models will be used to project future trends with and without proposed restoration actions. 

Objectives: Data Collection will use a combination of boat-based and stationary data collection to gather data on:

 Real-time and synoptic cross-sectional water velocities and discharge 

 Suspended load concentration and grain size distribution 

 Bed load and flux of sediment occurring through bed form migration 

 Sand sheet thickness 

 Water column turbidity 

 Data for characterizing sediment erodibility, entrainment, flocculation and settling, and deposition 

 Data to characterize bed morphology changes 

 Salinity and temperature 

 Other water quality parameters 

 All collected data sets will be archived, managed for quality control and made available for use by the 

modeling teams, the state and federal partners, and the general public.

Challenges:

 Dependent on field conditions

 Capturing complex spatial and temporal variability

Study Status:

 Collecting estuarine data (salt wedge) during low-water months of Sept-Oct 2013

 Plan to finish collecting data during high water conditions in spring 2014

 The Data Management Team is collecting and processing historic data sets.

 Data analysis and quality control review will continue through FY14.

Anyone seeking additional information on the MRHDM Study can visit the LCA program website at 

www.lca.gov, the New Orleans District LCA website at 

www.mvn.usace.army.mil/Missions/Environmental/LouisianaCoastalArea.aspx, or the CPRA website at

http://coastal.louisiana.gov/.

October 2013
U.S. ARMY CORPS OF ENGINEERS – NEW ORLEANS DISTRICT

7400 LEAKE AVENUE, NEW ORLEANS, LA 70118

Visit the following links to follow us on Facebook, Twitter and Flickr:

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http://twitter.com/teamneworleans

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LOUISIANA COASTAL PROTECTION AND RESTORATION AUTHORITY

450 LAUREL STREET, BATON ROUGE, LA 70808

http://coastal.louisiana.gov

Mississippi River Hydrodynamic 

and Delta Management Study

(1) LONGITUDINAL SURVEYS

One dimensional models need to be able to account for the 

processes that add/subtract from the water discharge, 

concentration and grain size composition of the suspended 

sediment. The surveys will begin above Old River Control (to 

examine the potential impact of the loss of water at the control 

structures) and extend to Head of Passes. The priority will be to 

examine progressive settling of suspended fines associated with 

low discharge (August-November, <500,000 cfs), during a period 

when there is little bed material load (sand) suspension. The 

following boat measurements will be made longitudinally and at 

cross-sections:

1. Water discharge and velocity by acoustic doppler current 

profiler (ADCP)

2. Suspended sediment load by point-integrative isokinetic 

sampler

3. Bedload transport by repeat multibeam bathymetric 

profiling

4. Bed grain size by bottom grab

5. Bed erodibility on cores using a mobile sediment flume 

laboratory

6. Other water quality parameters (salinity, flocculation, 

nutrients, etc.).

(2) to (5) BAR DYNAMICS SURVEYS

Multi-dimensional models need to be able to simulate (a) 

downstream transport of sand on lateral and point-bars in the 

lower river by dune migration, and (b) the complex exchange of 

sand grains between the bed and lower water column over dune 

fields. The following boat measurements will be made at each of 

the four bar sites:

1. Base map of the entire reach by multibeam bathymetry for 

model grid setup

2. Water discharge and velocity by ADCP 

3. Suspended sediment load by point-integrative isokinetic 

sampler

4. Bedload transport by repeat multibeam bathymetric 

profiling

5. Bed grain size by bottom grab

6. Other water quality parameters (salinity, flocculation, 

nutrients, etc.)

(6) ESTUARINE DYNAMICS SURVEYS

1D and multi-dimensional models need to be able to simulate the 

complex behavior of water, sediment and nutrients in the Ostrica 

(mile 24) to deepwater pass mouth(s) “estuarine” reach. Each of 

the field studies will have distinct goals, and in some cases, will be 

timed at different river discharge phase. This is because the salt 

wedge is known to emerge from the Southwest Pass channel only 

when water discharges at Tarbert Landing are below 300,000 cfs. 

The field studies are:

1. A single, bank-to-bank, multibeam bathymetry survey of the 

river reach for model grid setup between Ostrica and Head 

of Passes, and extending as far as navigable into the SW 

Pass, South Pass, and Pass a Loutre channels. It will also 

extend as far as navigable into the trunk channel of major 

river exits in this reach.

2. Two detailed (orthogonal and longitudinal) surveys will be 

carried out at low discharge (<300,000 cfs) of the Ostrica-toHOP reach designed to measure the salt wedge distribution, 

motion with tide and with change in discharge.

3. One detailed (orthogonal and longitudinal) survey will be 

conducted at moderate to high discharge (400,000-800,000 

cfs) concentrated within the Southwest Pass channel. This 

discharge range assures that the salt wedge will be confined 

to the Southwest Pass channel.

(red dots) MONITORING PLATFORMS

Data will be collected at hourly frequencies over the 24 month 

initial study period at several fixed sites on the river, taking 

advantage of existing USACE/USGS study sites.

A. Turbidity (OBS) – Optical backscatterance sensors 

(OBS) will be emplaced at Tarbert Landing, Baton Rouge, 

Belle Chasse, Mile 24 and Mile 2.6 to record pulses in 

sediment load and how these pulses are modulated 

through the tidal and estuarine reach. 

B. Nitrate – Solid-state, optical nitrate sensors will be 

emplaced at Baton Rouge, Belle Chasse and Mile 2.6 to 

examine whether nitrate levels change downstream 

through the tidal and estuarine reach at any phase of the 

discharge cycle. 

C. Discharge –A new discharge station will be established 

in the tidal-estuarine reach at Mile 2.6. Because water 

velocities (and hence calculated water discharge) are 

strongly modulated by tides and salt wedge processes, 

data will be collected with a 300 kHz horizontal ADCP at 

high frequencies (minutes).