September 16, 2009 Lora Hollingsworth, FDOT September 16, 2009 Lora Hollingsworth, FDOT Integrating Project Complexity and Risk Stormwater Management System Design Task Force

September 16, 2009 Lora Hollingsworth, FDOT Foundational Concepts  Greater Public Risks? Increased certainty of professional competence needed Increased certainty of professional competence needed  Greater Project Complex? Increased professional proficiency needed Increased professional proficiency needed

September 16, 2009 Lora Hollingsworth, FDOT Levels of Risk Level of ImpactHuman Safety OFW / Impaired Waters Property Damage MinimalNoneNoNone LowNoneNoMinor ModerateUnlikelyYesModerate SignificantPossibleSevere ExtremeClearly yes

September 16, 2009 Lora Hollingsworth, FDOT 1988 Agreement MinimalModerateLowExtremeSignificant Low Medium High Complexity Risk RLA: PE:

September 16, 2009 Lora Hollingsworth, FDOT Combined Risk and Complexity MinimalModerateLowExtremeSignificant Low Medium High Complexity Risk Minimal: Intermediate: Advanced: Competency -

September 16, 2009 Lora Hollingsworth, FDOT Levels of Complexity - Low  Single Basin Routing w/ Single Control Structure  No Infiltration Modeling  Small, Manmade Basin Hydrology  Multiple Pipes in Series (Small Storm Drain System)

September 16, 2009 Lora Hollingsworth, FDOT  Medium Size Basin Hydrology  Multiple Basins in Series with Multiple Control Structures  Small Interconnected Basins With Parallel Connections and Multiple Outfalls  Multiple Pipes in Series (Major Storm Drain System) Levels of Complexity - Medium

September 16, 2009 Lora Hollingsworth, FDOT  Recovery of Infiltration Basins with Simple Boundary Conditions  Exfiltration Trench Systems  Closed Regional Basin Levels of Complexity – Medium (Con’t)

September 16, 2009 Lora Hollingsworth, FDOT  Regional Hydrology  Infiltration Basins with Complex Boundary Conditions  Large Interconnected Basins with Parallel Connections and Multiple Outfalls  Soils Amendments Levels of Complexity - High

September 16, 2009 Lora Hollingsworth, FDOT Combined Risk and Complexity MinimalModerateLowExtremeSignificant Low Medium High Complexity Risk Minimal: Intermediate: Advanced: Competency -

September 16, 2009 Lora Hollingsworth, FDOT Minimal Risk / Low Complexity  Burger King with Wet Pond Draining to a Drainage Ditch ” – 18” pipes draining to the pond ” – 18” pipes draining to the pond Not an impaired waterway or OFW Not an impaired waterway or OFW

September 16, 2009 Lora Hollingsworth, FDOT Minimal Risk / Medium Complexity  Burger King with Wet Pond Draining to a Drainage Ditch Upstream retention Upstream retention Closed Basin Closed Basin  Mall Draining to a WMD Canal Trunk line 18” – 42” pipes draining to the pond Trunk line 18” – 42” pipes draining to the pond Exfiltration Trench Exfiltration Trench

September 16, 2009 Lora Hollingsworth, FDOT Minimal Risk / High Complexity  Burger King with Wet Pond Draining to a Drainage Ditch Upstream retention with Karst topography Upstream retention with Karst topography Soil amendments Soil amendments  Business Draining to WMD Canal Parallel interconnected ditches with control structures Parallel interconnected ditches with control structures Large regional flow through ditch within site Large regional flow through ditch within site

September 16, 2009 Lora Hollingsworth, FDOT Low Risk / Low Complexity  Small Residential Development with Wet Pond Draining to a Drainage Ditch ” – 18” pipes draining to the pond ” – 18” pipes draining to the pond Not an impaired waterway Not an impaired waterway

September 16, 2009 Lora Hollingsworth, FDOT Low Risk / Medium Complexity  Small Residential Development with Wet Pond Draining to a Drainage Ditch Upstream retention Upstream retention Closed Basin Closed Basin  Mall Draining to a WMD Canal Trunk line 18” – 42” pipes draining to the pond Trunk line 18” – 42” pipes draining to the pond Exfiltration Trench Exfiltration Trench

September 16, 2009 Lora Hollingsworth, FDOT Low Risk / High Complexity  Small Residential Development with Wet Pond Draining to a Drainage Ditch Upstream retention with Karst topography Upstream retention with Karst topography Soil amendments Soil amendments  Mall Draining to WMD Canal Parallel interconnected ditches with control structures Parallel interconnected ditches with control structures Piping large regional flow through ditch within site Piping large regional flow through ditch within site

September 16, 2009 Lora Hollingsworth, FDOT Moderate Risk / Low Complexity  Medium Sized Residential Development with Wet Pond Ditch drainage flowing to single pond Ditch drainage flowing to single pond Neighborhood streets (low speed) Neighborhood streets (low speed) Swale percolation ignored in design Swale percolation ignored in design Drains to an Impaired Waterway Drains to an Impaired Waterway Piping regional flow through 48” pipe within subdivision Piping regional flow through 48” pipe within subdivision

September 16, 2009 Lora Hollingsworth, FDOT Moderate Risk / Medium Complexity  Medium Sized Residential Development Upstream retention Upstream retention Closed Basin Closed Basin  Large Mall Draining to an Impaired Waterway Trunk line 18” – 42” pipes draining to the pond Trunk line 18” – 42” pipes draining to the pond Exfiltration Trench Exfiltration Trench

September 16, 2009 Lora Hollingsworth, FDOT Moderate Risk / High Complexity  Medium Sized Residential Development with Wet Pond Upstream retention with Karst topography Upstream retention with Karst topography Soil amendments Soil amendments  Large Mall Draining to WMD Canal Parallel interconnected ditches with control structures Parallel interconnected ditches with control structures Hardpan issues with perched water table Hardpan issues with perched water table

September 16, 2009 Lora Hollingsworth, FDOT Significant Risk / Low Complexity  Burger King with Wet Pond Drains to a DOT roadside ditch with pond downstream Drains to a DOT roadside ditch with pond downstream ” – 18” pipes draining to the pond ” – 18” pipes draining to the pond  Hospital with Wet Pond ” – 18” pipes draining to the pond ” – 18” pipes draining to the pond Swale percolation ignored in design Swale percolation ignored in design No exfiltration trench No exfiltration trench

September 16, 2009 Lora Hollingsworth, FDOT Significant Risk / Medium Complexity  Medium Sized Residential Development Draining to a DOT Roadside Ditch Upstream retention Upstream retention Closed Basin Closed Basin  Hospital Draining to a WMD Canal Trunk line 18” – 42” pipes draining to the pond Trunk line 18” – 42” pipes draining to the pond Exfiltration Trench Exfiltration Trench

September 16, 2009 Lora Hollingsworth, FDOT Significant Risk / High Complexity  Large Residential Development Upstream retention with Karst topography Upstream retention with Karst topography Soil amendments Soil amendments  Emergency Management Facility Draining to WMD Canal Parallel interconnected ditches with control structures Parallel interconnected ditches with control structures Quantify large regional flow through ditch within site Quantify large regional flow through ditch within site Piping large regional flow through 72” pipe within development Piping large regional flow through 72” pipe within development

September 16, 2009 Lora Hollingsworth, FDOT Extreme Risk / Low Complexity  Burger King with Wet Pond Draining to FDOT Curbed Highway ” – 18” pipes draining to the pond ” – 18” pipes draining to the pond No exfiltration trench No exfiltration trench Posted speed = 40 mph Posted speed = 40 mph

September 16, 2009 Lora Hollingsworth, FDOT Extreme Risk / Medium Complexity  Residential Development Draining to FDOT Curbed Highway Upstream retention Upstream retention Inflow pattern changed from sheet flow to point flow Inflow pattern changed from sheet flow to point flow Trunk line 18” – 42” pipes draining to the pond Trunk line 18” – 42” pipes draining to the pond Complex, interconnected upstream storage Complex, interconnected upstream storage

September 16, 2009 Lora Hollingsworth, FDOT Extreme Risk / High Complexity  Large Mall Draining to FDOT Curbed Highway Upstream retention with Karst topography Upstream retention with Karst topography Soil amendments Soil amendments Parallel interconnected ditches with control structures Parallel interconnected ditches with control structures Exfiltration trenches used for flood protection Exfiltration trenches used for flood protection

September 16, 2009 Lora Hollingsworth, FDOT DOT Perspective MinimalModerateLowExtremeSignificant Low Medium High Complexity Risk Minimal: Intermediate: Advanced: Competency -

September 16, 2009 Lora Hollingsworth, FDOT Questions / Discussion?