The Most Advanced Environmental Fluid Dynamics Code

Based on the Environmental Fluid Dynamics Code (EFDC) originally developed in the late 1980s by Dr. John M. Hamrick, DSI’s EFDC+ has become the gold standard for water systems modeling.

According to U.S. Environmental Protection Agency:

“The Environmental Fluid Dynamics Code (EFDC) is a multifunctional surface water modeling system, which includes hydrodynamic, sediment-contaminant, and eutrophication components. EFDC has been applied to over 100 water bodies including rivers, lakes, reservoirs, wetlands, estuaries, and coastal ocean regions in support of environmental assessment and management and regulatory requirements.

EFDC is a state-of-the-art hydrodynamic model that can be used to simulate aquatic systems in one, two, and three dimensions. It has evolved over the past two decades to become one of the most widely used and technically defensible hydrodynamic models in the world.”

US Environmental Protection Agency

DSI created EFDC+ by taking the original version of EFDC and vastly improving its speed, stability, and accuracy.  EFDC+ now far surpasses the features and performance of the legacy code. EFDC+ is also full open-source and available online.




MPI/OMP Hybrid

EFDC+ now uses a hybrid MPI/OMP domain decomposition approach for vastly improved model run times. Using cluster systems, this approach can be scaled up to run as much as 25 times faster than other approaches. MPI enables you to run models faster than ever before to meet tight project deadlines while maintaining performance.

Numerical Solutions

Develop robust and defensible numerical solutions for complex hydrodynamic and water quality problems with this leading-edge computational model.

Sigma-Zed Sub-Model

Accurately simulate systems with steep changes in bed elevation using the robust Sigma-Zed vertical layering approach, which reduces pressure gradient errors.

Fully Coupled Model

Save time and avoid mistakes with a fully coupled model. No external linkages are required between the hydrodynamic model and other sub-models. Sediments, toxics, or water quality sub-models are all natively linked for improved speed and performance. 

Supported & Open Source

Unlike many versions of the EFDC code, EFDC+ is centrally maintained and supported. This means that you have one go-to source for code improvements and reporting any bugs you think might be in the code. We fix them and release updated executable on our website and the full source code on Github.

SEDflume Sediment Model

As part of EFDC+, you can use Sandia National Laboratory’s state-of-the-art SEDZLJ sediment transport sub-model, which incorporates site-specific erosion rate (SEDflume) and shear stress data, while maintaining a physically consistent, unified treatment of bedload and suspended load. The model has now been further enhanced to support toxics.