Porter County and the Twin Creeks Conservancy District retained DLZ for stormwater rehabilitation and flood mitigation throughout Old South Haven. They wanted DLZ to study, perform detailed design services, and provide construction observation services. Our team was responsible for the replacement of the existing storm sewer system and mitigation of flooding throughout the square mile subdivision.
Public stakeholder meetings and interaction are essential in this tight-knit community, and the projects involved numerous meetings with the public. The study of the system included
- Video inspection for over 5 miles of existing storm sewer
- XP-SWMM hydrologic/hydraulic modeling of Squirrel Creek
- Storm sewer
- Interconnected detention basins
The initial study performed by DLZ recommended $20mn in improvements ranging from sewer lining to the relocation of storm sewers. The sewer lining was performed in areas where homes were too close to the sewer for excavation. DLZ also recommended enlargement of storm sewers, enhancements, and expansion of detention facilities, creek conveyance improvements, and water quality enhancements.
Furthermore, DLZ performed 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 a new storm sewer up to 54-inches in diameter and CIPP lining of the 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.