Flatford Swamp Hydrologic Restoration Feasibility Study (H089)

•How much excess water?•How to remove it from the swamp?•What to do with it once the flow is removed?

To MosaicTo Manatee County

To Mosaic

•Supply Timing and Delivery•Storage Options•Water Quality and Treatment Options

Site B

Site A

Flatford Swamp

•Simplified Reservoir Routing Model

•Daily Inflows, Rainfall and PEToProvided by Interflow, LLC, 2011oExisting Landuse ConditionsoUsed Extended Period of Record (16 years)

•Model Currently Includes All Parameters Except Seepage

oMay Include It Later with Refined Siting Information

•Outputs are Daily, Monthly and Annual

•Variability of Inflows and Delivery Limits•Water Quality and Treatment Requirements •Storage Type and Design Criteria •Operational Considerations

•Alternative 1: No Storage

•Alternative 2: Excavated Storage

•Alternative 3: Elevated Storage

•All Accomplish Flatford Swamp Diversion Objectives per MRWI Conceptual Plan

•All Evaluations Use 20 cfs Limit on Flows Delivered to Mosaic

Water Quality and Treatment

• Surface Water Sources• Coker Creek• Ogleby Creek• Maple Creek• Myakka River

• Period of Record (1990s to 2011)• Recent SWFWMD Data (2009 to 2011)

• Samples collected quarterly

• Seasonal Variability Evaluation (2008, FDEP Data)• Tributaries to Myakka River• Samples collected monthly

• Myakka River Has Better Overall Water Quality Than Tributaries

• 2008 FDEP Water Quality Data• Sulfates, conductivity readings– higher in dry season• TOC concentration – lower in dry season

• May Develop Water Quality Indicator Based on USGS Conductivity Values

• Treatment Technology Exists to Accommodate Seasonal Water Quality Variability

• Phosphate Beneficiation Process is Affected by Elevated Levels of Calcium and Magnesium

• Alternative Refinements and Costs• Regulatory Review• Final Report Due December 2012