Project Background and Purpose:

• Joint projects between the City of Tallahassee (COT) and Florida State University.

• The performance objective of the project was to model the watershed and maximize the stormwater attenuation and treatment capacities of the RSF to account for future development by the two parties.

 

 

Project Design / Implementation:

• SAI conducted final engineering design including permit coordination with FDEP and FDOT, preparation of construction plans and specifications, cost opinions, limited bidding assistance and limited construction administration services.

• The final design included a 28-acre (+/-) offline wet detention treatment and attenuation facility to serve future expansion of the FSU campus and downtown Tallahassee areas.

• Ancillary components of this facility include a diversion berm to prevent short-circuiting, a littoral zone, 225 feet of 12’ X 10’ box culvert under a major 4-lane State roadway, an intake structure with an inline floating skimmer and trash trap along the main channel, an outfall structure, channel improvements and relocation of a 36-inch sanitary sewer aerial crossing.

• Approximately 2,500 cubic yards of petroleum contaminated soil was identified at the north end of the RSF. The project was designed and implemented in two phases to allow for the remediation of the contaminated soil.

• SAI was responsible for all aspects of this project including securing and managing geotechnical, environmental, surveying and structural subcontracts. The project was fast-tracked using creative construction and permit phasing due to flooding problems along the Central Drainage Ditch. Construction of this regional offline treatment facility is almost complete. The only remaining tasks to be completed include submittal of the FEMA amendment and a few ancillary permit issues.

 

Stormwater Modeling / Investigation:

• SAI was contracted by the City of Tallahassee to assist its Stormwater Management Division and the Florida State University with the development of a 28-acre (+/-) Regional Stormwater Facility (RSF).

• Comprehensive stormwater modeling using the ICPR model for a 5.5 square mile watershed was conducted including model calibration/verification with 4 historical storm events, 5 rainfall gages and 4 continuous recorder stream gages.

• A detailed engineering report was prepared describing all findings of the study phase of the investigation.