Porter County and the Twin Creeks Conservancy District retained DLZ to study, perform detailed design services, and provide construction observation services for the rehabilitation of the existing storm sewer and mitigation of flooding throughout the one square mile subdivision. Outlet by Squirrel Creek, the subdivision contains aged infrastructure and experiences frequent flooding throughout the development, making roadways impassible during recurring storm events and flood structures, reducing the quality of life for the residents.
Public stakeholder meetings and public interaction are essential in this tight-knit community, and the projects involved numerous meetings with the public. Study of the system included the video inspection for over 5 miles of existing storm sewer, XP-SWMM hydrologic/hydraulic modeling of Squirrel Creek, culverts, storm sewer, and interconnected detention basins. The initial study performed by DLZ recommended $20 million in improvements ranging from sewer lining in areas where homes were too close to the sewer for excavation to the relocation of storm sewers. DLZ also recommended the replacement of storm sewers, enlargement of storm sewers, enhancements and expansion of existing detention facilities, creek conveyance improvements, and water quality enhancements.
DLZ was further selected to perform the survey, design, permitting, and construction observation for several phases outlined in the initial study. To date, the total value of construction of those facilities is approximately $5 million.
Construction projects implemented during these initial phases included the construction of new storm sewer up to 54-inches in diameter and CIPP lining of existing storm sewer with diameters up to 60-inches in diameter. New storm sewer outlets, roadway reconstruction, and relocation of storm sewers previously located under residential structures to areas where the storm sewer is more accessible for maintenance were also implemented.