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Planning for the Future & Higher Standards Stewart Creek Watershed Management
Frisco Watersheds
STEWART CREEK
20 SQ MI45 LINEAR MILES
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Google Aerial 1995
Google Aerial 2001
Google Aerial 2007
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Google Aerial 2015
Google Aerial 2017
2011 Watershed Study: Ultimate Conditions Results
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2011: Identified Hazards
Crossing Hazards
#* Medium #* Low Erosion Hazardskj#* High
City Reviews
Developer Revises Models
City Provides H&H Model(s) and Data
Locatedin the Floodplain? Adding Impervious area?
Developer has a plan
Prompt for Updated Models:
• ~ 90 Developments in Stewart Creek Watershed since 2008
• Incorporate Pond Data
• New Topography
• Land Use Changes
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2011 Existing Land Use2007 Existing Land Use
2015 Existing Land Use
2015 Ultimate Land Use
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2015 Watershed Study Results
Crossing Hazards
#* Medium #* Low Erosion Hazardskj#* High
2015: Identified Hazards
2015: 2-Year Velocity Summary
Velocity > 5 fps
Velocity < 5 fps
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Compare 2015 to 2011: Identified Hazards
#* 2015 Hazard #* 2011 Hazard Erosion Hazardskj
#* 2015 Hazard #* 2011 Hazard Erosion Hazardskj
Compare 2015 to 2011: Identified Hazards
#* 2015 Hazard #* 2011 Hazard Erosion Hazardskj
Compare 2015 to 2011: Identified Hazards
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• Overall Reduction in Q (12% at downstream end)
• Changes mostly due to more detail not development
• Overall reduction in area delineations
• Inclusion of detention facilities
2015 Ultimate Floodplain
2011 Ultimate Floodplain
2015 Ultimate Floodplain
2011 Ultimate Floodplain
2011 Drainage Areas
2015 Drainage Areas
Frisco Multi-Use Facilities
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2015 Ultimate Floodplain
2011 Ultimate Floodplain
2015 Ultimate Floodplain
2011 Ultimate Floodplain
• No Rise in 100-YR Ult • No Rise in Floodway
• Velocity Restrictions • No Velocity Restrictions
• FFE 2' Above 100-YR Ult
• FFE above FEMA 100-YR• Erosion Hazard Setback
• Crossings - 1ft Freeboard 100-YR Ult
Frisco Criteria above NFIP Requirements
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• Criteria for Smaller Storms • 100-YR control only
• No FP development allowed w/o Study
• Some FP development allowed
• Valley Storage• No Valley Storage
Regulation
Frisco Criteria above NFIP Requirements
• Benefits of Models
• City watersheds almost studied completely
• Next Steps
Matt Dubois, PE, CFM
City of Frisco
Katie Hogan, PE, CFM
Freese & Nichols, Inc.
