DSI

Global Experts in Surface Water Modeling

Environmental Engineering

Proven Environmental Management and Planning

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Water Resources

Real-time water management decisions

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Coastal Engineering

Impact analytics of
human activities on coastal systems

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Hydropower Engineering

Engineering and field support services for
hydropower projects

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Contaminated Sediments

Specialized studies of toxics fate and transport

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Community Support

Using professional expertise to
serve the community

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"DSI’s mission is to help our clients minimize and sustainably manage their environmental impacts through sound science. We do this by providing expert professional services and software solutions for Water Management and Planning worldwide, while maintaining a positive impact on employees, clients and other stakeholders."

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Consulting Services

DSI has over 30 years of experience in providing water resources planning, flooding analysis and control, reservoir systems, groundwater flow, toxics transport, and water quality consulting services. DSI offers considerable expertise on a worldwide basis in water resources and environmental projects.
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Engineering Software

DSI develops and maintains the EE Modeling System (EEMS), a compete modeling package for hydrodynamics, sediment transport, toxics transport, and eutrophication. DSI also develops custom software for clients to solve specific engineering problems.
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Real-time Modeling Systems

DSI has created real-time models for multiple clients to simulate hydrodynamics, temperature, and salinity. These models provide visualizations within 24-48 hours.
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Recent Projects

Client

USACE Jacksonville District

Project

From 2017 – To 2019

DSI submitted the final modeland report for use in manage-ment scenario analysis.

Services

Key Staff

Thomas Mathis

[email protected]

Szu-ting Lee

[email protected]

Nghiem Tien Lam, Ph.D.

[email protected]

Introduction

The St. Johns River (SJR) flows north, from its headwaters in the marshes of Indian River County, to the Atlantic Ocean near Jacksonville. The lower St. Johns River (LSJR) is defined as the portion of the river that extends from the confluence of the St. Johns and Ocklawaha rivers near Welaka north to the mouth of the SJR at Mayport in Jacksonville; the LSJR is about 120 miles in length. Tidal marshes surround the lower part of the estuary, where the river is mostly channelized due to urban development around Jacksonville, Florida (riverine segment). The LSJR estuary is dominated by wetlands (greater than 50 percent of the floodplain area), which host a diverse range of ecological communities. Both the composition and structure of these wetlands exhibit a strong geographical pattern corresponding to gradients in tidal amplitude, salinity, and soil texture and composition.

Project Goal

The purpose of this study was to evaluate potential impacts on the aquatic habitat of salinity intrusion into the estuary, and create a basis for evaluating multiple management scenarios to support decision-making.

Lower St. Johns Estuary

Application

The EFDC+ hydrodynamic and salinity model was used to model the LSJR estuary. Five separate simulation periods were used for model calibration and validation. Data collected by USACE, NOAA, USGS, and the SJR Water Management District were used to calibrate the EFDC+ model for water surface elevation and salinity. Following model calibration, an 8.5-year Production Run (PRP) from January 2008 to June 2016 was run to evaluate the long-term trends in salinity intrusion and analyze the long-term behavior of the estuary in relation to salinity stress on locations in the estuary with submerged aquatic vegetation beds (SAV) and wetlands.

A habitat analysis of submerged aquatic vegetation and wetlands was performed, which serves as a baseline for comparison with alternative management and future change scenarios for the basin.

The final model and the modeling report were submitted to the client to be used in developing and evaluating additional management scenarios.

Visualizing Salinity Change in Lower St Johns River.

Client

Confidential

Project

From 2018 – Ongoing

The final modeling report was submitted to the clients to support remedial design.

Services

Key Staff

Paul Craig, P.E.

[email protected]

Thomas Mathis

[email protected]

Jeffrey Y. Jung, PhD

[email protected]

Bui Minh Hoa

[email protected]

Introduction

The Willamette River originates in the Cascade Mountain Range, flowing through northwestern Oregon for 187 miles to its confluence with the Columbia River. The final 26.5-mile stretch of river downstream of Willamette Falls before the Columbia River confluence is considered the Lower Willamette River. It is a slow-moving, tidally influenced segment that experiences intermittent reverse flow at high tide during the low flow season (usually summer and early fall). Portland Harbor is defined as the 9.9-mile dredged reach of the Lower Willamette River between River Miles 1.9 and 11.8. The harbor is surrounded by light and heavy industry and mixed commercial and residential development around the City of Portland. A variety of industrial activities historically occurred and continue to take place around the harbor, including marine shipping terminals, bulk fuel facilities, manufacturing, and other commercial operations. In 2000, USEPA placed the Portland Harbor Superfund site on a National Priorities list (NPL).

Project Goal

Develop a scientifically defensible model to simulate the hydrodynamic and sediment erosion and transport processes in Portland Harbor to support contaminate source identification and cleanup cost allocation.

Lower Willamette River and the Portland Harbor Project Area.

Application

DSI developed a hydrologic model of City of Portland private and public drainages, loosely coupled with multi-scale hydrodynamic and sediment transport models of the Lower Willamette and Columbia Rivers. The multi-scale hydrodynamic models included a large-scale, coarse grid model for the entire domain and nested, fine grid, high-resolution models for individual sediment management areas (SMAs). This modeling system coupled the simulation of the large-scale hydrodynamic and sediment transport processes of the site with the ability to provide model predictions on the scale of individual SMAs. The system included fully coupled morphologic feedback of hydrodynamics and sediment bed elevation changes between the models to address existing conditions and future mitigation exports. 

DSI submitted the final model and the modeling report to the model sponsors to support remedial design, recovery monitoring, and the cleanup cost allocation process.

Client

Alberta Environment and Parks, Canada

Project

2016 – 2017

Model, report, and training delivered for use in management scenario evaluation.

Services

Key Staff

Paul Craig, P.E.

[email protected]

Nghiem Tien Lam, Ph.D.

[email protected]

Bui Minh Hoa

[email protected]

Introduction

Alberta Environment and Parks (AEP) has developed a South Saskatchewan Region Plan (SSRP) to flexibly and proactively manage the cumulative effects of human activity on surface water quality within the South Saskatchewan Region. Scientific models used to evaluate the effectiveness of various management and engineering environmental options have been a key component of the management approach. As part of SSRP, AEP commissioned an in-stream water quality model for the Little Bow River.

The Little Bow River watershed is located in the headwaters of the Oldman River Basin in the southern region of the Province of Alberta. As a major tributary of the Oldman River, the Little Bow River receives diverted flows from the Highwood River, direct precipitation, local runoff, and municipal/industrial discharges. The Upper Little Bow River Basin occupies an area of approximately 3,491 km$^2$, and supports a wide variety of natural resources, including forests, minerals, wildlife, and agricultural lands.

Project Goal

The project goal was to develop a hydrodynamic and water quality model of the Little Bow River as an assessment tool to support flood mitigation work related to the Highwood-Little Bow diversion system and Little Bow River.

Little Bow River Watershed

Application

Using Environmental Fluid Dynamics Code Plus (EFDC+), DSI developed a two-dimensional (2D) and three-dimensional (3D) model of the Little Bow River, which extended about 165 km and included an in-stream reservoir (Twin Valley), and a 55 km tributary (Mosquito Creek). The reaches were represented by 2D grids and the reservoir was represented using 3D grids. The model boundary condition inputs were provided using monitoring data and a watershed model developed using Soil and Water Assessment Tool (SWAT).
The model simulated hydrodynamics, temperature, ice, dissolved oxygen, nutrients, macrophytes, algae, and the processes involved in the complete nutrient cycle. Following the calibration of the model for all physical, chemical, and biological parameters, DSI used the calibrated model of the complete system to evaluate multiple management scenarios, including flow diversion at Highwood, reservoir operations, and Waste Water Treatment Plant (WWTP) effluent water quality control.

DSI submitted the complete model and the final report to AEP and provided training to agency staff. AEP uses the model for management scenario evaluation.

This video demonstrates how the Little Bow River WQ simulation helps better understand and manage water resources.

The major services provided by DSI include

Water Resources

DSI provides an integrated understanding and approach to addressing the ever increasing stresses on our planet’s water resources. DSI provides engineering services and hydrologic, hydraulic and hydrodynamic modeling support to assist the Client in providing solutions that help optimize competing demands.
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Environmental Engineering

DSI provides solutions to support Environmental Management and Planning. DSI has experience in over 100 engineering and analysis projects covering a wide range of conditions and client needs.
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Hydropower

DSI provides comprehensive hydrologic, hydraulic, sediment transport, environmental and engineering services to meet our Client’s requirements. DSI engineers have experience in dozens of hydroelectric power projects in North America and Asia.
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Coastal Engineering

DSI provides hydrodynamic and engineering services for coastal and harbor circulation, plume and industrial plant outfall/diffuser mixing and plume studies, shoreline protection, and navigation, DSI has demonstrated real-time hydrodynamic model development experience to assist in harbor and environmental management.
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Morphological Studies

DSI provides for the study and analysis of morphology and sediment transport for a diverse range of projects. These include hydropower dams, coastal studies for port and harbor authorities, and complex river and delta system studies of both clean and contaminated sediment transport.
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Contaminated Sediments

DSI has extensive experience in the study and analysis of contaminated sediment fate and transport. Our expertise ranges from collection and analysis of field data, to data processing, the modeling of hydrodynamic systems for movement of PCBs, dioxins, herbicides and pesticides.
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Groundwater

DSI provides modeling and analysis of groundwater for a diverse range of projects. These include groundwater control and water supply for open pit and long-wall mining operations, nuclear and thermal power plants, and dams as well as groundwater contaminated with organic compounds, radionuclides and/or metals.
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Field Data Collection & Management

In order to provide a complete solution for our clients DSI has developed extensive experience in the field of data collection, processing, and analysis for data supporting hydrodynamic and water quality modeling studies. Our experience indicates that client decision making and model development are critically dependent on reliable and accurate data.
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Community Support

DSI takes seriously its responsibility to make a positive contribution to the larger community in which DSI operates. In Vietnam, DSI is undertaking a number of Community Support projects as well as offering technical expertise to the NGO community in water and public health related areas.
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