Phase 4 Drainage - Drainage Masterplan

Work Complete to Date:

• Full inventory and assessment of existing drainage infrastructure for phase 4 study area.
• Water level monitoring stations installed near Ocean Boulevard, county park, and marina.
• Rainfall monitoring station installed at county park.
• Provided short-term maintenance recommendations based on field assessments for phase 4 study area.
• Completed existing conditions hydrologic and hydraulic assessments of phase 4 infrastructure for both extreme and typical storm events. This includes high intensity rain bombs as well as elevated tides from sea level rise.
• Developed preliminary solutions for high-priority areas within the phase 4 study area as identified through the existing conditions assessment and confirmed by city staff. High-priority areas are classified as those that experience more than 6 inches of flooding for more than 30 minutes.
• Identified preliminary solutions for low-priority areas within phase 4 study area.
• Reviewed island-wide ditch/channel maintenance program.

Next Steps:

• Develop cost estimates for preliminary solutions for high-priority areas.
• Continue evaluating alternatives for high-priority areas to fiend the most efficient and economical long-term solution.
• Continue evaluating options to solve flooding in low-priority areas.
• Identify funding options for all alternatives.
• Set up meeting and work with residential property owners to evaluate development standards in terms of stormwater management.
• Identify and consult with specialty contracts (e.g., stream restoration contractors) to develop long-term solution for island-wide canal/ditch/channel systems.

• Inventory and conditions report is complete and presented in easily understood Google Earth format (see attached screenshot example)
• Modeling to identify problems is complete
• Staff met with Davis & Floyd on April 24th to verify issues identified and modeling match conditions found in the field
• Davis & Floyd is working to develop conceptual solutions to issues identified
• Davis & Floyd is scheduled to discuss their progress and possible solutions with Public Works Committee at their May 4th meeting
• Davis & Floyd will soon begin reviewing City’s development standards to address shortcomings.

• Project is progressing well and on schedule
• 625 watersheds delineated
• Inventory of current conditions is complete
• 2D and 3D modeling is underway
• Monitoring has not measured any significant rain events yet
• Potential projects are being identify now
• On track for project completion by the end of the year

• Project is progressing well and on schedule.
• 625 watersheds delineated
• Inventory of current conditions should be completed this week
• 2D and 3D modeling begins week of February 14
• Monitoring has not measured any significant rain events yet
• Davis & Floyd, City staff visited Eadie’s work this week to visualize problems
• Assessment and evaluation of collected data is underway
• On track for project completion by the end of the year

• Project is progressing well and on schedule.
• Field work is complete
• Rainfall and water level monitors are installed and operational
• Assessment and evaluation of collected data is underway
• On track for project completion by the end of the year