Project Background and Purpose:

• Under contract with the Orange County Department of Public Works, SAI prepared a comprehensive stormwater master plan.

• The objectives of the project included the following:

1. Update the original master plan based on new information and evaluate the effectiveness of the previously implemented capital improvements (SAI prepared the original master plan 15 years earlier), and

2. Provide the County with a tool for planning future capital improvements with respect to flood protection.

 

Project Design / Implementation:

• 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 structures and roads was conducted.

• The model input data, predicted flood stages, and survey data were all incorporated into a graphical information system (GIS) to evaluate flood conditions under a number of scenarios and manage the data.

• Capital improvement recommendations included numerous culvert replacements and channel improvements.

• Detailed cost evaluations were prepared for each of the recommended alternatives.

• An implementation plan for sequencing proposed improvements was prepared.

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

• Pre-application meetings were conducted with the SJRWMD to present and discuss the proposed improvements.

 

Stormwater Modeling / Investigation:

• The project area is characterized by a high groundwater table with very little topographic relief and frequented with shallow depressions.

• An extensive inventory of the drainage infrastructure was conducted. A user-friendly graphically oriented database was developed for the management of this information.

• Comprehensive stormwater modeling of the 7.1 square mile 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.

• In order to address historically reported flooding concerns, the model was refined to include some secondary drainage systems.