Additional Features

EFDC+ has been enhanced far beyond the original EPA EFDC code.  In addition to the enhancements mentioned in other sections, DSI has made further improvements to meet user and project needs including the following.

Dynamic Memory Allocation

While other versions of EFDC require recompiling of source code for each new model, EFDC+’s dynamic memory allocation allows you to use the same executable between modeling applications without recompiling. This helps prevent inadvertent array-overwrite errors and provides more traceability for the source code. More details on dynamic memory allocation can be found here.


For the installation and operation of turbines and wave energy converters in rivers, tidal channels, ocean currents, and other waterbodies, EFDC+ fully incorporates the Marine-Hydrokinetic (MHK) module to simulate their placement and potential effects. Based on Sandia National Laboratory’s modified EFDC code, this EFDC+ module has been extended to work with the new Sigma-Zed vertical layering scheme.

MHK device being moved into location for hydrokinetic power generation.

NetCDF Formatted Output

EFDC+ has been upgraded to allow export of model results formatted according to netCDF-CF (netCDF- Climate and Forecast) conventions. This upgrade makes it possible for  EFDC+ output to be directly read and displayed on web servers, supporting real-time models.

Connection of Sub-domains

EFDC+ can now use grids with two or more disconnected sub-domains in the IJ space.  Thus, EFDC+ can connect sub-domains along the E-W faces on cells as well the N-S faces. This enables the development of intricate grid configurations to address the requirements of complex physical domains.

Bi-Directional Boundary Flows

EFDC+ can now handle bi-directional flows with the Withdrawal-Return and Hydraulic Structures boundary conditions.