Engineering Disciplines


Services

Numerical Modeling

Nearshore Hydrodynamic Study, Orange County, CA.

In support of the Corps' Coast of California Storm and Tidal Waves Study, NCI conducted a comprehensive analysis to define the prevailing and extreme nearshore wave climate along 30 miles of metropolitan shoreline. The purpose of the study was to provide input for sand management planning and to better define design criteria for shoreline stabilization structures and development. Local, regional and global meteorology was studied to identify the dominant patterns of deep water wave generation. Nearshore transformation of wave energy along the study area was described using a state-of-the-art spectral model which included island sheltering effects. The analysis was synthesized into recurrence estimates of expected wave conditions throughout the County's shoreline using a Monte Carlo simulation. The numerical model simulated the seasonal variation in deep water wave occurrences and the resultant heights, periods, and angles of incidence after propagation to the Orange County coastline. Extreme wave climate was determined using a storm track hindcast technique.

Redondo Beach-King Harbor, Redondo Beach, CA.

NCI performed a comprehensive engineering study of the existing Federal breakwater system to identify improvements that would lesson harbor shoaling and storm damages to the interior mooring basins and development. Studies included detailed analysis of extreme events to determine the occurrence of critical wave exposure; energy transmission through the existing breakwater structures; associated storm wave runup; and damages to interior mole areas and basins. Alternatives were formulated to raise, modify, seal, and extend the rubble-mound breakwaters and improve inner harbor protective devices. A Federal plan of action was identified on the basis of storm damage reduction need and resultant economic benefit to the local commerce.

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Santa Barbara Harbor, Santa Barbara, CA.

NCI performed a reconnaissance study to identify improvements to mitigate navigation and storm damage due to harbor shoaling and wave-induced flooding. Studies included analyses of deepwater and shallow water waves, wave transformation, sediment transport, sediment budget, entrance channel shoaling rates, tides, water circulation and harbor flushing. Alternative improvements evaluated consisted of extending the existing breakwater; constructing a new east breakwater and/or a new detached breakwater; extending the groin; installing a new beach groin; improving the Leadbetter Beach revetment; dredging West Beach and/or a new channel; removing the sandbar breakwater; and purchase of a dredge. This evaluation considered design constraints, cost estimates, operation and maintenance costs, and cost-benefit ratios.

Puerto Juluapan, Bahia de Santiago, Mexico.

NCI performed a water circulation analysis for a proposed shallow depth artificial embayment to be constructed within existing uplands on the Pacific Ocean. The semi-enclosed harbor was numerically modelled using a three-dimensional, finite element computer program to simulate the tidal hydraulics and circulation patterns within the irregularly-shaped water body. Detailed temporal and spatial descriptions of the varied tidal flows were provided to support a technical assessment of the projects's environmental feasibility.

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Castaways Marina, Newport Beach, CA.

Water quality assessment studies were performed to support preparation of a project EIR for a small-craft harbor located within the sensitive Upper Newport Bay estuary. NCI evaluated the baseline conditions and potential impacts associated with alternative mooring basin and channel dredging plans. Existing water circulation patterns were summarized, and numerical and physical model studies were conducted to estimate the extent of impacts that might be caused by the proposed improvements. Specific water quality parameters that were reviewed during the study included sedimentation, turbidity, and floating debris accumulation.

Morro Bay Harbor, Morro Bay, CA.

A reconnaissance study was performed by NCI to identify existing navigation and maintenance problems within the Federal inlet. Work included detailed analyses of wave conditions, littoral sediment movement, sediment budget, entrance channel shoaling, tides, water circulation and harbor flushing. Structural and non-structural plans were formulated and evaluated to reduce breaking wave conditions in the entrance channel and alleviate channel shoaling. Alternatives were evaluated on the basis of technical merit, economic benefit, and environmental impact. The preferred plan consisted of a unique dredging plan that resulted in significant cost savings over conventional structural solutions.

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San Onofre Lagoon Estuary Enhancement Report, Camp Pendleton, CA.

NCI prepared a report recommending an enhancement plan for the improvement of the San Onofre Lagoon, which is located on the U.S. Marine Corp's Camp Pendleton base. Work consisted of site visits, data collection, engineering analysis and evaluation of the site's hydrology/oceanography conditions to identify erosion characteristics, and proposing a range of feasible alternatives including structural and non-structural measures to enhance the San Onofre Lagoon. A detailed hydrodynamic analysis under small or moderate flood conditions was performed using the modules of RMA2 and SED2D of the Surface-Water Modeling System (SMS) that was developed by the Corps of Engineers to simulate the flow field within the lagoon boundary and to estimate the potential sediment scouring and re-deposition in the proposed excavation areas for various lagoon habitat improvement options.

The RMA2 modeled results indicate that flow pattern in San Onofre Lagoon will be altered under each proposed enhancement option, particularly during a flood event, as the direct consequence of the changed lagoon configuration. Based upon the SED2D modeled results, sediment deposition occurs throughout most of the lagoon region, particularly in the proposed expansion areas. It was estimated that 20 percent of the storage capacity would be refilled under a 5-year flood event. Therefore, the estimated re-excavation cycle is approximately from 5 to 10 years.

The effectiveness of each lagoon enhancement alternative in improving the lagoon marine habitat and preventing bank erosion was then assessed for the selection of an optimal alternative. In addition, construction costs for the proposed alternatives were also presented in the analysis, based upon each itemized estimate of mobilization/demobilization, construction material, required construction equipment and manpower.


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Santa Margarita Estuary Hydrodynamic Analysis, San Diego County, CA.

This project involved the hydrodynamic analysis using water levels, river flow data, and lagoon bathymetry to complete an estuary analysis for currents and water mixing within the Santa Margarita River Estuary using the Surface-Water Modeling System (SMS). This modeling simulation was conducted in support of a feasibility study for a constructed wastewater treatment wetland to assess the potential impacts of any discharge of treated water on the estuarine water quality. Fieldwork consisting of orthophotgraphy and topographic mapping, and bathymetric surveys was conducted to formulate the model's base map for numerical simulations. The tidal-induced estuarine hydrodynamics including water level and currents were modeled with the consideration of the wetting and drying processes within the estuary boundary. The model calibration was performed using the water level data at the USGS gage located in the estuary. In addition, coastal processes within the shoreline segment of the estuary region were also assessed. The modeled results are to be used to determine potential accumulation of secondary contaminants from the wastewater discharge during times of no direct connection to the ocean.


Yosemite Canal Wetlands Restoration, San Francisco, CA.

The Yosemite Canal Wetlands Restoration is currently an on-going project. Yosemite Canal is part of the Candlestick Point State Park Recreational Area. The purpose of the project is to expand wetlands in the area, provide public access, and improve wildlife habitats. A previous phase of the project involved developing alternatives, estimating construction costs, and preparing a feasibility report. NCI is responsible for hydrodynamic analysis, surveying, preparing grading plans, designing public paths, preparing construction cost estimates, and preparing contract documents.

Our design will consider, and dispose of as necessary, contaminated sediments in the area. The modeling study was part of the wetland restoration project and includes both the hydrodynamic simulation and sediment transport simulation for the Yosemite Canal and South Basin. The RMA2 model within the Surfacewater Modeling System (SMS) was used for the hydrodynamic simulation and the SED2D model was applied for the sediment transport simulation.

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Hurricane Katrina Flooding Evaluation, New Orleans, LA.

NCI was contracted by WTHF to review the Interagency Performance Evaluation Team (IPET) reports that were prepared by several independent investigation teams to understand “what happened” in the New Orleans areas during Hurricane Katrina.  After a site inspection and a comprehensive report review, NCI was further requested to perform hydraulic & hydrodynamic numerical modeling analyses in order to determine the vertical elevations and their time histories of water levels, wave runup and water overtopping of the levee systems for specific areas of interest within the New Orleans region.  Various hydraulic and hydrodynamic model simulations including HEC-GeoRas, HEC-Ras, RMA2 and ADCIRC were required to characterize local hydrodynamics, internal drainage and flooding as well as levee performance.  An extensive data collection and analysis was conducted to identify additional data needs to be collected for the engineering analysis.

 

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