PANTHER HOLLOW:
INTERVENTIONS FOR WATERSHED RESTORATION MAY 23, 2011
PROJECT GOALS • Understand Panther Hollow hydrodynamics. – Natural and Existing
• Develop attainable surface water goals. – Return baseflow to Phipps Run and Panther Hollow Stream. – Mitigate the “flashiness” of runoff during heavy storm events.
• Identify range of possible interventions & priority locations for pilot projects. • Identify opportunities in the 4 Mile Run Watershed • Create a watershed restoration plan for Panther Hollow • Design and construct three pilot projects in the watershed.
REVISED PANTHER HOLLOW WATERSHED BOUNDARY
ORIGINAL AREA = 780 AC
REVISED AREA = 384 AC
PRE-COLUMBIAN SUBBASINS PHIPPS RUN = 67 AC
PANTHER HOLLOW LAKE = 13 AC
PANTHER HOLLOW STREAM = 300 AC
DIRECT DRAINAGE TO PANTHER HOLLOW PHIPPS RUN = 67 AC
PANTHER HOLLOW LAKE = 13 AC
PANTHER HOLLOW STREAM = 97 AC
LAND COVER Visitor’s Center Phipps First Tee Golf Course
• Fair to Good: average urban forest condition • Poor to Fair (hydric areas): less than 50% canopy coverage with invasive species within a probable wetland area • Poor to Fair: less than 50% canopy coverage with invasive species
LAND COVER Fair-Good Woodland and Forest
Poor-Fair Woodland and Turf
Poor-Fair Hydric Woodlands and Emergent Marsh
LAND COVER
WHAT’S HAPPENING NOW? Water from these areas typically makes its way into the CSO.
Crowned street
Clogged inlets
Steep slopes and low curbs could allow for runoff to reach the watershed during heavy storms.
WHERE IS THE RUNOFF COMING FROM? Land Cover
Runoff Volume by Land Cover
POTENTIAL STRUCTURAL INTERVENTIONS • Reduce Impervious Cover – Street Edge Measures
• Rain Gardens/ Bioretention and Vegetated Swales • Pervious Pavement
• Infiltration Basins, Beds, Dry Wells, Trenches, Continuous Tree Trenches
• Forest Restoration
POTENTIAL NON-STRUCTURAL INTERVENTIONS • Protect/Utilize Natural Flow Pathways to Slow Down
Stormwater and Reduce its Volume • Landscape Restoration
• Landcover Conversion • Stop Mowing or Less Mowing
• Sustainable Landscape Management Practices • Golf Course Management
• Right-of-Way Management • Meadow and Forest Management
PHIPPS RUN BASIN • Watershed with historic stream. • Road was constructed over the stream.
PHIPPS RUN BASIN
PHIPPS RUN BASIN • Where is runoff coming from?
• What are the constraints? - Road bisects - Golf course
PHIPPS RUN BASIN | INFILTRATION TRENCH • Walk through potential interventions - Swale behind trees - Pedestrian walking down street
MAP OF PHIPPS (MED – AA to revise)
Reduce Impervious – Street Edge Measures
PHIPPS RUN BASIN | POROUS PAVEMENT • Walk through potential interventions - Swale behind trees - Pedestrian walking down street
MAP OF PHIPPS (MED – AA to revise)
Pervious Pavements
PHIPPS RUN BASIN | RAIN GARDENS AND VEGETATED SWALES
Reduce Impervious – Street Edge Measures
Reduce Impervious – Street Edge Measures
Rain Gardens and Vegetated Swales
Rain Gardens and Vegetated Swales
PHIPPS RUN BASIN | WET MEADOW
WET MEADOW
PHIPPS RUN BASIN | LANDCOVER CONVERSION
LANDCOVER CONVERSION | turf to meadow, turf- woodland
LANDCOVER CONVERSION | turf to meadow, turf- woodland
PHIPPS RUN BASIN | FOREST ENHANCEMENT
PHIPPS RUN BASIN | FOREST ENHANCEMENT AND EROSION CONTROL
PANTHER HOLLOW BASIN • Watershed with historic stream. Stream was beheaded by neighborhood development.
PANTHER HOLLOW BASIN
PANTHER HOLLOW BASIN • Where is runoff coming from?
• What are the constraints? - Pros: - Cons: Steep slopes, eroded soils
PANTHER HOLLOW BASIN | STORAGE & SLOW RELEASE
PANTHER HOLLOW BASIN | STORAGE AND SLOW RELEASE
PANTHER HOLLOW BASIN | STORAGE AND SLOW RELEASE
PANTHER HOLLOW BASIN | STORAGE AND SLOW RELEASE
PANTHER HOLLOW BASIN | LANDCOVER CONVERSION
PANTHER HOLLOW BASIN | LANDCOVER CONVERSION
PANTHER HOLLOW BASIN | LANDCOVER CONVERSION