Ghent Neighborhood League Briefing Living at Sea Level & Flooding Risks Tuesday, August 11, 2015: Chrysler Museum Presentation by: Tom 757-761-0676 tom@mcneilan.com
The Virginia Tidewater For 400+ years, water has been our best friend. It defines our: area and landscape, its environment, and its economy. Over the years, we have modified the physical landscape to our advantage. But, we now face increased conflicts between the natural environment and the built environment. And our friend becomes increasingly more threatening.
Early Maps of Area Early maps show abundant bays, wetlands and swamps 10% of Norfolk is filled land 1880
Land Form & Topography The Hague & South Ghent Pre-development Landform Today s Topography 1894 Former Creek Drainages Locations of Surface Drainage Pathways and Low-lying Areas Today Storm water & run-off drain to the Hague System typical 60+ years old
Subsurface Conditions Elizabeth River Midtown Tunnel (between Norfolk & Portsmouth) Location Map Site Map Pre-Development Morphology Slide #5 +10 0 Soft, compressible CLAY +10 0-50 -50 Elevation, feet -100 Top of Yorktown Formation -100 Elevation, feet -150-170 Stiff Hard CLAY Dense SAND Dense SILT -150-170
Hague Area Topography
Storm Water System Performance Typical flood extent - depth map for Existing Condition 1) Increases area of rainfall flooding 2) Increases depth of rainfall flooding 3) Holds water upstream longer and increases duration of flooding Verify 10 YR Condition Increasing Flood Depth Tidal surge: Rainfall Controlled Analyses results for coincident 10 year Rainfall and 10 year Tidal Surge Event Ghent Neighborhood League Briefing Tidal Controlled June 11, 2015
Nuisance Flooding In many areas, nuisance flooding is increasing and Routinely occurs during astronomical high tides, and during minor storms Hours per year when water overtopped bank of the Hague Data from Ezer & Atkinson, 2014 The Hague in Norfolk Year Eastern end of the Hague with Chrysler Museum in background April 23, 2013 @1900 hours. Tide is ~El +4.5 ft (re: MLLW) and ~1 to 1.5 ft above MHHW Implication Over Location the last Map nine decades there has been >10-fold increase in the hours tides in the Hague have flooded the adjacent streets. Nuisance flooding averages 2-6 hours per week.
Dutch Perspective Dutch Landscape - A delta landscape, penetrated by rivers, subject to sea and river flooding with highdensity urban areas and abundant agricultural lands Land Use Water is where the environment meets the economy Flood Prone Landscape
Dutch Water Management Perspective Evolution of Dutch Water Management Perspective - Transition from Fighting the Seas to Living with Water Historical: Storms and reclamation of land from the sea The Dutchman with his finger in the dyke 1953 North Sea Storm (comparable : to Katrina) Bigger, higher and stronger dykes and flood walls A 30+ years of capital infrastructure projects 1990s Recognition of changing river flows, environment, and sea level leading to. New Paradigm a Holistic perspective of Living with Water and Room for the River Responses have evolved from grey (hard) infrastructure to mixed grey (hard) and green (soft) responses 1421
Dutch Water Management Perspective Transformation from Fighting the Seas to Living with Water recognized that Additional protection will be required, BUT such protection shall be created within a context of an integrated water management approach i.e. green solutions Include multiple lines of defense and adaptation: Regional-scale protection Neighborhood District-scale actions Block- and parcel-scale efforts National funding for water management is ~1% of NL GDP
Dutch Water Management Perspective New Orleans (post Katrina) Water Management Plan Courtesy of Greater New Orleans Regional Economic Development Inc. Waggoner & Ball Bosch Slabbers Pre-Katrina System Technocratic pump and drain system designed to move water as fast as possible Proposed Approach Slow Store & Use Drain Excess
Dutch Dialogue Virginia: Life at Sea Level What is a Dutch Dialogue? Multi-disciplinary, multi-cultural, multi-generational Dutch, US, local & regional: experts, government, academics, citizens & stakeholders Multi-day design studio look at: 1) regional and 2) proto-typical local landscape and water management challenges Guiding Principals for a Dutch Dialogue Urban Designers Civil Engineers Work from a large Lawyers Economists perspective in both scale & time Be Architects careful with water Planners Hydrologists retain, store and drain to slow runoff Landscape Architects Regulatory Specialists Work with the system not against it Use Local drawings Focus to Areas share perspectives among different disciplines & stakeholders This speeds the Norfolk process Tidewater and focuses Dr. the District discussion Dare Hampton be innovative NN Market think Creek big Dare to think outside the box Don t accept solutions that only work Strive for solutions that both work and add value
Dutch Dialogue Virginia: Life at Sea Level Regional Perspective of the Tidewater History and physical landscape Economy and infrastructure Classify the landscape Understand the challenges Evaluate the opportunities Elevation and Urban Density Infrastructure & Federal facilities Land - Water Boundary
Dutch Dialogue Virginia: Life at Sea Level Norfolk s Tidewater Drive District Focus Area History physical landscape urban & infrastructure fabric Land use, density and neighborhood fabric Economy, challenges, identified goals & vision, and opportunities 1895 NS RR Bridges
Dutch Dialogue Virginia: Life at Sea Level Tidewater Dr. District Historical Development 1944 1965 1980 Ghent Neighborhood League Briefing June 11, 2015
Dutch Dialogue Virginia: Life at Sea Level Tidewater Dr. District Neighborhoods St Paul s Quadrant Harbor Park South of Brambleton Chesterfield Heights Dutch Dialogue Premises: Inter-neighborhood Connectivity increases mobility, reduces fragility, increases resilience, and improves economic potential. Inter-neighborhood Gateways increase sense of place and, neighborhood identity, and attract opportunity. Targeted Neighborhood Outcomes: Chesterfield Heights: Neighborhood re-vitalization, increased resilience & mobility. South of Brambleton North of I-264: Redevelopment, connection between NSU & Downtown, on site water storage. South of Brambleton South of I-264: Off-site water storage for St Pauls Quadrant (and significant reduction in that factors risk to re-development), connection between NSU & Downtown. St. Pauls Quadrant: Regional redevelopment opportunity, add to economic base in an environmentally friendly manner, expand core housing, reconnect to Downtown & Harbor Park Harbor Park: Expand river-frontage of Downtown, add regional attractions, promote regional multimodal connectivity.
Dutch Dialogue Virginia: Life at Sea Level Tidewater Dr. District Watersheds & Drainage Colors show Current Topography Current Tidewater Dr. District Watersheds Historical Shorelines & Creeks: Pre-development Circa 1880
Dutch Dialogue Virginia: Life at Sea Level Tidewater Dr. District Shoreline Conditions
Dutch Dialogue Virginia: Life at Sea Level Tidewater Dr. District Layering the Considerations Water & Water Storage Connectivity
Dutch Dialogue Virginia: Life at Sea Level Tidewater Dr. District
Topography EVMS CHKD Sentara Harrison Opera House Chrysler Glass Studio Chrysler Museum