CPWG engaged to update St. Pete Beach’s Stormwater Master Plan.
CPWG Focus for this Stormwater Master Plan
- Update GIS Stormwater Database
- Prepare Recommendations for Improvements
- Prepare a Budget for Recommended Improvement
CPWG Performed Field Reconnaissance To Identify
- Detention Ponds
- Control Weirs
- Outfall Pipes
CPWG recommended Improvements Included
- Public Information Process
- Removal of Marine Growth in the Outfall Pipes
- Backflow Prevention Devices a the Outfalls
- Stormwater Pump Station
Stormwater Master Plan for St Pete Beach, FL
St Pete Beach, FL
Cribb Philbeck Weaver Group, Inc. (CPWG) prepared an update to the City of St. Pete Beach’s 1993 Stormwater Drainage Plan. The primary focus of this Stormwater Master Plan was to update the City’s 1993 Plan, update the City’s GIS stormwater database, prepare recommendations for improvements to reduce flooding in certain drainage basins within the City, and prepare a budget for recommended improvement projects for the City to use for long range planning. During this master planning process, an in-depth look at the hydrology and hydraulics of 25 drainage basins within the City was performed identifying areas with extensive flooding problems and the causes of those problems. Additionally, water quality issues associated with NPDES and TMDL regulations were reviewed.
CPWG began the process by collecting and reviewing data from a number of sources to develop a comprehensive Stormwater Master Plan for the City. Data collection was focused on identifying and quantifying hydraulic elements within 25 primary drainage basins. Existing reports and plans were obtained, reviewed, and categorized.
The CPWG stormwater team performed field reconnaissance for each drainage basin to verify existing conditions. Field notes were taken to document the location, type, size, length and, number of structures (culverts, detention ponds, control weirs, inlets, manholes, and ditches, etc.). Photographs were taken of each drainage structure to document the condition of the structure at the time of the field investigation.
CPWG Stormwater experts used the data the collected to create a computer model to simulate flooding events for certain storm events. The 25-year, 24-hour storm event (9-inches of rain within 24-hours) was chosen to identify the flooding risk within the 25 drainage basins. The model allowed our team to track the quantity and quality of runoff created within each sub-basin. The resulting model allowed our Engineers and Planners to accurately represent any combination of stormwater controls within the study area to determine their effectiveness in managing stormwater, tide water, and sewer overflows.
Stormwater improvements were identified within each of the 25 priority drainage basins to reduce flooding and provide some measure of water quality improvement when possible. The improvements focused on the following areas:
Community Support. CPWG recommended a well-planned public information process to inform and gain the active support of the community for the proposed projects. A phased approach was recommended with public education occurring first followed by construction of one major high profile project.
Removal of marine growth that occurs in each of the City’s outfall points into the bay. Remove oysters growing in the open outfall pipes to the point where sunlight is not able to penetrate into the pipe,
Backflow prevention devices at the outfalls to reduce inundation from the bay during high tides and storm surge events. These devices function as a check valve to allow flow in only one direction and prevent backflow during high tides or storm surge events.
To complete the plan CPWG recommended Stormwater Pump Stations with back-up generator at the outfall pipes for flooding reduction during major storm events, especially during high tides. A pump station would be required to reduce flooding when the tide water is higher than the roadway inlet rims.