US Army Corps of Engineers
Great Lakes and Ohio River Division

Huntington District

Navigation System Models

Navigation system models are the primary tools for evaluation of investment actions. These models estimate investment benefits, project delays and other key navigation impacts used in formulation decisions. The Center is responsible for maintaining and upgrading several computer models that are essential to the LRD inland navigation planning program. The major ones include the Waterway Analysis Model (WAM) and the Ohio River Navigation Investment Model (ORNIM). The shallow-draft WAM measures lock capacity and delay using a simulation-based approach. While the deep-draft WAM essentially performs the same functions as the shallow-draft version, it also computes vessel costs.

The ORNIM and its pre- and post- processing programs are used to measure equilibrium and optimum traffic levels for an inland waterway system (e.g. the ORS), lock tonnage and transit costs, calculate the corresponding benefits for navigation improvements and to prioritize investments. The Center will continue to refine and develop models critical to the success of the Division’s navigation mission. Future model refinements include modifications to incorporate estimation of environmental suitability indices and to increase the consideration of risk and uncertainty.

Normal Maintenance - Normal maintenance activities entail storage of models and associated data files in rented computer space, as well as fees for the use of specialized software routines and computer libraries.

  • Model Upgrades - In addition to maintaining the models in a ready-to-use state, the ORNIM, WAM and other models must be upgraded periodically to maintain their validity.
  • Model Development - In addition to maintaining and upgrading the models, there is a continuous need to modify and expand the models to capture newer economic methodology, increased quantification of risk and uncertainty, environmental effects and to accommodate increased input information.
    • ORNIM - Version 3.4 of the ORNIM has been completed as part of the Ohio River Mainstem System Study and replaced the TCM-EQ models in FY 03. ORNIM needs further expandsion to optimize congestion fees and calculate environmental suitability indices. Additional documentation and ITR is needed and additional development of this tool will focus on making it more readily adaptable to answering questions beyond the Ohio River, making it easier to use, and making the output graphically oriented.