The System Wide Model

The Metropolitan Sewer District of Greater Cincinnati (MSDGC) completed a three-year project to develop a hydraulic model of the sewer system in 2003. One of the largest models of its kind ever constructed at the time, the System Wide Model provides the District with an extraordinary tool to evaluate existing and projected conditions within the sewer collection system.

What is a Model?

A hydraulic model is a computer-generated replication of the sewer system that can simulate the movement of flow through a piped network. The image to the left is an example of the output from the flow simulation. Within the District's service area, sanitary sewers 12" and larger, and combined sewers, 18" and larger are included in the System Wide Model.

What are the benefits?

Overloaded pipes can create a myriad of problems. Sewer backups and overflows present some of the more severe problems attributed to overloaded pipes. The causes are oftentimes extremely complex in nature and therefore difficult to both understand and resolve. A system model provides the means to view flow levels and velocities, and surcharge conditions in many areas of the sewer network all at the same time. By making changes to the computerized model, dquo&l;what if” scenarios are developed to simulate proposed system modifications prior to construction . In addition to determing the impact to the immediate area, these simulations allow for the evaluation of downstream impacts to determine the best holistic design solution.

The benefits of the Model do not stop there. As development continues at a rapid pace throughout many parts of Hamilton County, the need increases to extend the sewer system. Well-informed decisions can be made when determining the impact of the added flow to the downstream system and to the receiving treatment plants.