Lawson-Fisher Associates was selected by the City of Mishawaka to study the Woomer Ditch Watershed. The project started with a study to evaluate the existing storm sewer system and develop recommendations for drainage improvements. The study identified the need for a large diameter trunk storm sewer as well as an extensive storm sewer collection system within the Normain Heights area.
The design included a 120-inch diameter trunk storm sewer extending from the St. Joseph River north over 6,300 LF. Tunneling was chosen as the most cost-effective method for installation of the large diameter sewer and also provided the advantage of limited impacts and minimal surface restoration to those residents and businesses along the route. The tunnel included a double track crossing of the CANAC US Railroad. Lawson-Fisher Associates provided early coordination with the railroad to facilitate permitting of the crossing. The contractor experienced difficulties with the sandy (non-cohesive) soil conditions throughout the project and particularly at the railroad crossing. The railroad became undermined and the project was stopped. Lawson-Fisher Associates worked with the contractor and the railroad to finalize a plan to allow the contractor to proceed.