Project Background and Purpose:

• Under contract with the City of Tallahassee, SAI prepared a comprehensive stormwater master plan.

• The objectives of the project included the following:

1. Identify the extent and causes of flooding,

2. Develop and analyze solutions to address flooding, and

3. Evaluate recommended options under future land-use conditions.

 

Project Design:

• Severe yard, street, and first floor structure flooding of several areas within the watershed was predicted or historically observed.

• In order to effectively characterize flooding and develop improvements to address the flooding problems, an extensive survey of residential and commercial structures and roads was conducted.

• Capital improvement recommendations included expansion of an existing pond (Boone Blvd.) and the replacement of over 4,400 feet of severely eroded ditches with box culverts and circular pipe (Tupelo Terrace).

• Recommendations also included innovative oversized inlets to reduce reconstruction costs of the existing collection system.

• An implementation plan for sequencing proposed improvements was prepared.

• Permitting through the FDEP and public presentation were conducted.

• The flood plain boundaries and floodways were revised and submitted to FEMA for amendment of the Flood Insurance Rate Map and Flood Insurance Study documents.

• A detailed engineering report was prepared summarizing the existing conditions results and evaluated design alternatives.

 

Stormwater Modeling / Investigation:

• The project area is a highly urbanized portion of the City of Tallahassee, Florida.

• Comprehensive stormwater modeling of the 750 acre watershed was conducted using the FEMA approved ICPR model.

• An existing conditions model was developed through extensive site reconnaissance as well as the review of numerous reports, previous studies, permits, construction plan sets, aerials, and topographic maps.

• The model was calibrated/validated based on one storm event and the location of two high water marks.

• The rainfall distribution for the model verification storm was developed based on information from a nearby rain gage.

• A critical storm evaluation was conducted.