10 Nov 2021

Houston Ship Channel Expansion Improvement Project – Navigation Channel Improvement Study: Ship Simulation Results

Abstract: In 2020, the US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory, provided technical oversight during a navigation study to assist the Galveston District evaluation of different channel widening alternatives for larger ships transiting the Houston Ship Channel (HSC), Texas. The widening proposals encompassed several areas of the HSC including the Bay Section, the Bayport Ship Channel, Barbours Cut Channel, and the Bayou Section. The study was performed at the San Jacinto College Maritime Technology and Training Center (SJCMTTC) Ship/Tug Simulator (STS) Facility in La Porte, TX. The SJCMTTC STS is a real-time simulator; therefore, events on the simulator happen at the same time rate as real life. A variety of environmental forces act upon the ship during the simulation transit. These include currents, wind, waves, bathymetry, and ship-to-ship interaction. Online simulations of the project were conducted at SJCMTTC over a 3-week period – May through June 2020. Several mariners including Houston Pilots and G&H tugboat Captains participated in the testing and validation exercises. ERDC oversight was performed remotely because of the COVID-19 pandemic. Results in the form of engineering observations, track plots, and pilot interviews were reviewed to develop final conclusions and recommendations regarding the final design.

29 Oct 2021

Mobile Harbor, Alabama Navigation Study: Ship Simulation Report

Abstract: Mobile Bay is a large estuary located in the southwest corner of Alabama, which connects to the Gulf of Mexico. Mobile Harbor contains the only port in the state that supports ocean-going vessels. Some of the larger vessels calling on the port experience transit delays and limited cargo capacity, so a study was conducted by the US Army Corps of Engineers, Mobile District (CESAM), and the Alabama State Port Authority to investigate channel improvements. In 2017, the US Army Engineer Research and Development Center (ERDC) assisted CESAM in screening proposed deepening and widening alternatives in Mobile Bay by completing a Feasibility Level Ship Simulation (FLSS) study using the ERDC Ship/Tow Simulator. These lower-resolution databases from the FLSS study were used as a foundation to complete a more robust navigation study in 2020 to test the proposed modifications to Mobile Harbor. During this study, three main areas were focused on: a bend easing, a passing lane, and a turning basin. Testing of the proposed design was evaluated over the course of 2 weeks with eight pilots. Assessment of the proposed modifications was accomplished through analysis of ship simulations completed by experienced local pilots, discussions, track plots, run sheets, and final pilot surveys.

18 Aug 2021

Houston Ship Channel Expansion Channel Improvement Project (ECIP) Numerical Modeling Report: BABUS Cell and Bird Island Analysis

Abstract: The Houston Ship Channel (HSC) is one of the busiest deep-draft navigation channels in the United States and must be able to accommodate increasing vessel sizes. The US Army Engineer District, Galveston (SWG), requested the Engineer Research and Development Center, Coastal and Hydraulics Laboratory, perform hydrodynamic and sediment modeling of proposed modifications in Galveston and Trinity Bays and along the HSC. The modeling results are necessary to provide data for hydrodynamic, salinity, and sediment transport analysis. SWG provided three project alternatives that include closing Rollover Pass, Bay Aquatic Beneficial Use System cells, Bird Islands, and HSC modifications. These alternatives and a Base (existing condition) will be simulated for present (2029) and future (2079) conditions. The results of these alternatives/conditions as compared to the Base are presented in this report. The model shows that the mean salinity varies by 2–3 ppt due to the HSC channel modifications and by approximately 5 ppt in the area of East Bay due to the closure of Rollover Pass. The tidal prism increases by 2.5% to 5% in the alternatives. The tidal amplitudes change by less than 0.01 m. The residual velocity vectors vary in and around areas where project modifications are made.

21 May 2021

Approaches for Assessing Riverine Scour

Abstract: Calculating scour potential in a stream or river is as much a geomorphological art as it is an exact science. The complexity of stream hydraulics and heterogeneity of river-bed materials makes scour predictions in natural channels uncertain. Uncertain scour depths near high-hazard flood-risk zones and flood-risk management structures lead to over-designed projects and difficult flood-risk management decisions. This Regional Sediment Management technical report presents an approach for estimating scour by providing a decision framework that future practitioners can use to compute scour potential within a riverine environment. This methodology was developed through a partnership with the US Army Engineer Research and Development Center, Hydrologic Engineering Center, and St. Paul District in support of the Lower American River Contract 3 project in Sacramento, CA.

14 May 2021

Brunswick Harbor Numerical Model

Abstract: The Brunswick area consists of many acres of estuarine and marsh environments. The US Army Corps of Engineers District, Savannah, requested that the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, develop a validated Adaptive Hydraulics model and assist in using it to perform hydrodynamic modeling of proposed navigation channel modifications. The modeling results are necessary to provide data for ship simulation. The model setup and validation are presented here.

30 Apr 2021

Empirical analysis of effects of dike systems on channel morphology of the Lower Mississippi River

NOTE: There was an title error in MRG&P Report No. 36, which was published 3/2/2021 . A new PDF has been attached to the record with the correct title. This email has the correct title as well. No other changes were made.

25 Aug 2020

PUBLICATION NOTICE: New York/New Jersey Harbor Sedimentation Study: Numerical Modeling of Hydrodynamics and Sediment Transport

Abstract: The New York/New Jersey Harbor (NYNJH) is a vital economic resource for both the local economy and the entire US economy due to the vast quantity of imports and exports handled by the numerous ports in this waterway. As with most ports, there is a significant, recurring expense associated with dredging the navigation channels to the authorized depths. In an effort to determine the impact of channel enlargements (“the project”) on dredging volumes, a numerical model study was performed. The advantage of a numerical model study is the ability to isolate individual system modifications and associated impacts in terms of dredging volumes. Five years (1985, 1995, 1996, 2011, and 2012) were simulated for both the with- and without-project conditions to determine the impact of the channel deepening on the dredging requirements for a wide range of meteorological conditions including storm events. The numerical model results were analyzed to provide insight into which locations will experience increased/decreased deposition and quantify the amount of increase/decrease for a given channel reach. The model results indicate a relatively minor increase in the total dredge volumes for the NYNJH with the increase being insignificant in comparison to the natural variability in dredge volumes across years.

11 Aug 2020

PUBLICATION NOTICE: Post-Project Monitoring of a Navigation Solution in a Dynamic Coastal Environment, Smith Island, Maryland: Year One of Post-Project Monitoring

Abstract: In 2018, jetties and a sill were constructed by the US Army Corps of Engineers (USACE) adjacent to the Sheep Pen Gut Federal Channel at Rhodes Point, Smith Island, Maryland. These navigation improvements were constructed under Section 107 of the Continuing Authorities Program. Material dredged for construction of the navigation structures and realignment of the channel were used to restore degraded marsh. Following construction and dredging, 1 year of post-project monitoring was performed to evaluate the performance of navigation improvements with respect to the prevention of shoaling within the Sheep Pen Gut channel, shoreline changes, and impacts to submerged aquatic vegetation (SAV). Given the short period of record after the completion of the navigation improvements, it was difficult to draw conclusions regarding stability of the channel, structures, and shoreline. Therefore, this report documents methodology and baseline conditions for monitoring, except for SAV, which was found to be potentially impacted by construction. A second year of monitoring was funded by the USACE Regional Sediment Management Program for fiscal year 2020. Findings can be used to inform plan formulation and design for USACE navigation projects by illuminating considerations for placement of structures to prevent shoaling and by informing SAV management decisions.

25 Jun 2020

PUBLICATION NOTIFICATION: Effect of Tropical Storms and Precipitation on Dredging Volumes: Houston-Galveston, TX, and Mayport, FL

Abstract: This study characterizes infilling responses within dredged navigation channels to rainfall from tropical storms and hurricanes. This project created a web tool based on the methods described in this report. This report discusses the different analysis methods considered to relate storm and rainfall to dredging volumes at two pilot sites, Galveston, TX, and Mayport, FL. A comprehensive storm Impact Factor for hurricanes was developed to quantify the impact at a site based on proximity, duration, and wind speed. The methods vary based on the length and timing of periods of storms and rainfall prior to a dredge event. At Galveston, TX, when 2-year dredging volume totals were compared to hurricane activity occurring in the previous 2 years, the maximum dredging volume removed was higher after higher hurricane activity when compared to low activity periods. The average amount dredged was higher following periods of high hurricane activity. At Mayport, FL, dredging volumes were compared to hurricane activity occurring since the last dredging action took place. Similarly to Galveston, TX, the maximum dredging volume removed was higher after higher hurricane activity periods when compared to low activity periods. The average amount dredged was higher following periods of high hurricane activity.

30 Apr 2020

PUBLICATION NOTICE: Geochemical Fingerprinting of Sediment Sources Associated with Deposition in the Calcasieu Ship Channel

Abstract: This Regional Sediment Management Technical Note (RSM-TN) demonstrates how geochemical fingerprinting techniques were used to distinguish probable sediment sources to the Calcasieu Ship Channel (CSC). These methods were applied to sediment samples collected from suspected source areas identified in past sediment budget studies. The techniques can be used by managers and stakeholders to make more informed decisions on best practices for managing sediment and mitigating sediment deposition within the channel.