the lakes, princess anne plaza, and windsor woods combined ... · windsor lake trashmore northgate...
TRANSCRIPT
The Lakes, Princess Anne Plaza, and Windsor Woods
Combined Drainage Project
November 2018
PROGRAM OVERVIEW
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▪Elevations in the area are low
▪Frequency and severity of storms increasing
▪ Infrastructure is 50 years old +/-
• Princess Anne Plaza: 1961
• The Lakes (East of Plaza Park): 1964
• Windsor Woods: 1966
• The Lakes (West of Plaza Park): 1976
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Background
Background
▪Rainfall from Hurricane Matthew (October 2016) resulted in extreme flooding
▪Records indicate approximately 800 residences in the Project area had various levels of damage during Matthew (modeling approximates 1,400)
▪Many streets were impassable
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Issues
▪ Low Elevations
▪ Intense Storm Events
▪Tidal Impacts
▪ Inadequate Stormwater Pipe Capacity
▪ Lack of Stormwater Storage
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PROJECT AREA
Natural Drainage Patterns
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Tidal Influence
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Tidal Impacts
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0 to 2 Feet NAVD 88Tidal Impacts
Inundation AreasBetween Elevations:
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0 to 4 Feet NAVD 88Tidal Impacts
Inundation AreasBetween Elevations:
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0 to 6 Feet NAVD 88Tidal Impacts
Inundation AreasBetween Elevations:
120 to 8 Feet NAVD 88Tidal Impacts
Inundation AreasBetween Elevations:
Project Goals
▪ 10-Year Design Storm
▪No more than 3-inches of water over the road crown▪5.6 inches of rainfall in 24-hours▪10% chance of being exceeded in any given year
▪ 100-Year Design Storm
▪No flooding of structures ▪9.5 inches of rainfall in 24-hours▪1% chance of being exceeded in any given year
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Solutions
▪ Construction of Gates to Block Incoming Tides
▪ Construction of Stormwater Pumping Stations
▪ Additional Lake Storage Capacity
▪ Additional Retention/Storage Lakes
▪ Construction of Barriers
▪ Construction of Stormwater Drains
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Preliminary Concept Plan
Lynnhaven P
kw
y
Lake
Windsor
Lake
Trashmore
Northgate Plaza
Ball Fields
POTENTIAL SOUTH
TIDE GATE &
CHANNELS
LOCATION
POTENTIAL NORTH
PUMP STATION AND
TIDE GATE LOCATION
WINDSOR WOODS PUMP
STATION AND TIDE GATE
LOCATION
POTENTIAL
STORMWATER
RETENTION PONDS
NEW STORM
DRAINS WILL BE
INSTALLED IN
THE PROJECT
AREA