Innovative Strategies & Adaptive Restoration Approaches ... · Innovative Strategies & Adaptive Restoration Approaches for Tidal and Nontidal Areas Given Changing Coastal Conditions
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Innovative Strategies & Adaptive Restoration Approaches
for Tidal and Nontidal Areas Given Changing Coastal Conditions
reduce vulnerability, rethink management, resilient approaches
Darcy Turner & Joe Berg Biohabitats, Inc.
jberg@Biohabitats.com
Envision a world where the earth’s complex living systems are intricately linked and delicately balanced with their surroundings. Where your actions conserve critical habitat; where your project restores ecological processes; or where your footprint regenerates natural systems.
Ecological Restoration Regenerative Design Conservation Planning
Core practice areas
SCIENCES aquatic ecologists terrestrial ecologists restoration ecologists conservation biologists geologists hydrogeologists fluvial geomorphologists foresters soil scientists
Biohabitats’ team
ENGINEERING ecological engineers civil engineers water resource engineers Chemical engineers
DESIGN landscape architects natural resource planners
SUPPORT GIS Technicians CAD Technicians construction inspectors
Biohabitats’ whereabouts
reduce vulnerability, rethink management, resilient approaches
Context: Anne Arundel County, Maryland
Chesapeake Bay Watershed
530 miles of shoreline
Eastern Continental Shelf
(subsidence, post glacial readjustment)
reduce vulnerability
Vulnerability Assessment: (Sea Level Rise Strategic Plan Anne Arundel County, 2011)
vulnerability = susceptibility to flooding (storm surges) and inundation from sea level rise
adverse impact = increased groundwater elevations (sewers, storm drains, wells and septic systems
Scenario 1 0-2 ft inundation
2,193 acres vulnerable 62% are woodlands and wetlands
water lines 26,684 feet sewer lines 89, 092 feet
storm drain pipes 22,880 feet septic systems 5,206
private wells 4,718
Scenario 2 0-5 ft inundation
6,905 acres vulnerable 56% are woodlands and wetlands
water lines 53,729 feet sewer lines 306,865 feet
storm drain pipes 66,212 feet septic systems 7,238
private wells 7,633
reduce vulnerability
Relevant Key Issues:
(Sea Level Rise Strategic Plan Anne Arundel County, 2011)
Loss of Ecologically Significant Land Shoreline Erosion
Impaired Public Infrastructure Private Well and Septic
Scenario 1 0-2 ft inundation
1,600 acres of loss of ecologically significant land
Result: increase in shoreline erosion
loss of protection against storm surges increased coastal flooding
Scenario 2 0-5 ft inundation
4,500 acres of loss of ecologically significant land
Result: increase in shoreline erosion
loss of protection against storm surges increased coastal flooding
reduce vulnerability
Development Potential of Vulnerable Areas:
(Sea Level Rise Strategic Plan Anne Arundel County, 2011)
Chesapeake Bay Critical Area Regulations FEMA Regulations
49,450 acres in Critical Area
Scenario 1 0-2 ft inundation
2,079 acres of 2.193 acres in critical area 4% of total critical area is vulnerable 94% of inundation acreage is within
FEMA AE Zone (tidal and non-tidal 100-year floodzone)
Scenario 2 0-5 ft inundation
6,585 acres of 6,905 acres in critical area 13% of total critical area is vulnerable
94% of inundation acreage is within FEMA AE Zone
(tidal and non-tidal 100-year floodzone)
reduce vulnerability
Protection of Coastal Ecosystems: (Sea Level Rise Strategic Plan Anne Arundel County, 2011)
Protection and restoration of high priority shoreline
Acquire lands with program open space or other preservation funds
Target areas for wetland forest mitigation projects
(off-site mitigation for private developers)
Promote conservation easements (resource protection through tax incentives)
rethink management
Reduce Sea Level Rise Impacts:
(Sea Level Rise Strategic Plan Anne Arundel County, 2011)
Revise regulation to discourage the granting of variances and modifications to stream and wetland impacts
Revise the County’s development regulations to increase
stream and wetland setbacks (State Critical Area Commission Regulations)
Evaluate regulatory and non-regulatory recommendations that
could be incorporated into development plan review and approval
rethink management
Living Shoreline Act 2008
CWA MS4 Credits
Annual Shoreline Management Credits* Runoff Reduction Practice Credits**
Regenerative Stormwater Conveyance**
*(MS4 load reductions, MDE approved, under consideration by CBP) **(MS4 load reduction and impervious area treatment credits, adopted by CBP)
resilient approaches (“Adaptive” restoration techniques)
Green Infrastructure - Regenerative Stormwater Conveyance
(stormwater collection and conveyance – ephemeral conditions)
Regenerative Design - Regenerative Gully & Stream Restoration
Living Shorelines
Ecological Engineering
Biomimicry
Provisioning services
Regulating services
Supporting services
Cultural services
ecosystem services water
food (seafood and game), crops, wild foods, and spices energy (hydropower, biomass fuels)
carbon sequestration and climate regulation waste decomposition and detoxification
purification of water and air flood attenuation
crop pollination pest and disease control
nutrient dispersal and cycling seed dispersal
primary production cultural, intellectual and spiritual inspiration
recreational experiences (including ecotourism) Resilient Approaches
Green Infrastructure uses vegetation, soils, and natural processes to manage water and create healthier urban
environments. USEPA
Nature can be harnessed to provide critical services for communities, protecting them against flooding or excessive heat,
or helping to improve air and water quality, which underpin human and environmental health. When nature is harnessed by
people and used as an infrastructural system it's called “green infrastructure.” ASLA
Resilient Approaches
Regenerative Stormwater Conveyance Road-side ‘losing streams’ instead of pipes
Resilient Approaches
Green Infrastructure
Green Infrastructure
Holladay Park Anne Arundel County, Maryland Jabez Branch (receiving stream)
From piped drainage to conveyance that treats and reduces runoff
STORMWATER MANAGEMENT SUMMARY TABLE PHASE 1
Criteria
Volume Required
(cubic-feet)
Volume Provided
(cubic-feet)
Net Difference (cubic-feet)
Water Quality Volume (WQv) 8053 31032 22979
Reccharge Volume (Rev) 2336 24673 22337
Channel Protection Storage Volume (Cpv) 18295 47652 29357
Resilient Approaches
Green Infrastructure Regenerative Stormwater Conveyance
Holladay Park (RSC instead of piped drainage) Jabez Branch (receiving stream)
From piped drainage to runoff treatment and reduction
0
10
20
30
40
50
60
70
10 11 12 13 14 15 16 17 18 19 20
Dis
char
ge (c
fs)
Time (hours)
Existing Runoff versus RSC Outflow during 100-year Event
Existing
RSC Outflow
RSC Outflow minus Exfiltration
Event Existing RSC Outflow RSC Outflow Minus Exfiltration
(cfs) (cfs) (cfs) 1-yr 0.81 0 0.35 5-yr 10.1 1.87 6.06 10-yr 18.35 8.73 13.94 25-yr 33.4 22.86 29.85 100-yr 66.14 55.14 64.24
Resilient Approaches
Green Infrastructure Regenerative Stormwater Conveyance
From piped drainage to runoff treatment and reduction
P has e 1-Orig inal Des ig n C urrent C os ts
P ipe L F G rading/E xcess $248,750.0015" 1453 S WM P ond $80,131.0018" 408 P ipe $23,194.0021" 48 R isers/s tructures/headwalls $30,000.0024" 517 24" P ipe $8,420.0027" 470 S andstone Weirs $14,360.0030" 52312" x14" 50 T otal $404,855.00Total L F 3469
C os tsS WM P ond 216,710.00$ R C P 592,158.75$ S WM Ac c es s R d 8,900.00$ F enc es for S WM P ond 10,700.00$
T otal 828,468.75$
L ayout $44,934.00S ediment C ontrols $21,971.00
Holladay P ark- C os t C omparis on
Resilient Approaches
Green Infrastructure Regenerative Stormwater Conveyance
Holladay Park (RSC instead of piped drainage) Jabez Branch (receiving stream)
Reduced costs
Green Infrastructure
Resilient Approaches
Regenerative Stormwater Conveyance
Holladay Park (RSC instead of piped drainage) Jabez Branch (receiving stream)
Benefits to receiving streams – reduction of flashy flows, improved water quality and improved baseflow
Regenerative Design – Moving Beyond Sustainability
Design approach based on the value of living within the limits of available renewable resources without environmental degradation. John Lyle
In a sustainable system, lost ecological systems are not returned to existence. In a regenerative system, those lost systems can ultimately
begin "regenerating" back into existence. Not attributed
A design paradigm where human activities are deeply integrated with living systems, continuously building biological diversity, resilience
and community spirit. Not attributed
Resilient Approaches
Carriage Hills Pre-restoration Anne Arundel County, Maryland
Resilient Approaches
Green Infrastructure & Regenerative Design Regenerative Stormwater Conveyance
Piped Drainage & Ephemeral Gully Restoration
Watershed: Severn River Physiographic Province: Coastal Plain
Drainage Area: 11 acres
Land Use: Suburban land use, public
easement and HOA property
Project Area: 11 acres, 425 linear feet of stream (intermittent along downstream)
Slope: 10 -15%, with 22-ft incised, having an adverse effect on shallow groundwater and downstream flows
Resilient Approaches
Regenerative Stormwater Conveyance
Carriage Hills Pre-restoration Stormdrain Removal & Ephemeral Gully Restoration
Piped drainage & gully to wetland complex
Green Infrastructure & Regenerative Design
Resilient Approaches
Regenerative Stormwater Conveyance
Carriage Hills Pre-restoration Stormdrain Removal & Ephemeral Gully Restoration
Sand bed overlain with riffles and pools Green Infrastructure & Regenerative Design
Resilient Approaches
Sand seepage bedding used as haul road Regenerative Stormwater Conveyance
Green Infrastructure & Regenerative Design
Carriage Hills During Construction Stormdrain Removal & Ephemeral Gully Restoration
Riffle Grade Controls
Resilient Approaches
Regenerative Stormwater Conveyance During Construction - built downstream up
Green Infrastructure & Regenerative Design
Carriage Hills During Construction Stormdrain Removal & Ephemeral Gully Restoration
Resilient Approaches
Carriage Hills Post-restoration Stormdrain Removal & Ephemeral Gully Restoration
Regenerative Stormwater Conveyance Post Restoration
Stormwater is now conveyed in a non-erosive fashion into a series of broad and flat (in cross section) and vertically undulating (in profile) riffles and pools, and converted to
groundwater through natural percolation through soils and converted into groundwater
Green Infrastructure & Regenerative Design
Source: Solange Filoso, University of Maryland
Resilient Approaches
Runoff Reduction Regenerative Stormwater Conveyance
Carriage Hills Pre-restoration Stormdrain Removal & Ephemeral Gully Restoration
Green Infrastructure & Regenerative Design
Progression of Stream Restoration From Conveyance to Integrated Stream and Floodplain Techniques
Time
Func
tiona
l Val
ue
Pipe – Bury Headwater Streams
Conveyance/Concrete Channels
Integrated Stream and Floodplain Techniques
Next ?
Natural Channel Design
Rip-Rap, Gabion, Bank and Bed Treatments
Regenerative Design
Conveyance of Flows
Stream Restoration for Bay TMDLs/NPDES Credits
Next ?
Protection/Promotion of Built Environment
Aquatic Habitat Enhancement
Water Quality Improvements
Improved Channel Form
Func
tiona
l Val
ue
Time
Regenerative Design Drivers of Stream Restoration From Conveyance to Integrated Stream and Floodplain Techniques
incised groundwater
Floodplain Reconnection Approach Integrated Stream and Floodplain Techniques
Regenerative Design
Floodplain Elevation
Incised Channel Bottom
Riffle Grade Control
Regenerative Design Floodplain Reconnection Approach
Towson Run Tributary Watershed: Jones Falls, Patapsco River
Physiographic Province: Northern Piedmont Plateau
Drainage Area: 444 acres Project Area: 15 acres, 4,000 linear feet of stream
Description
Area (acres)
Percentage
Institutional 117.3 26% Low Density Residential 3.9 1%
Medium Density Residential 53.4 12% High Density Residential 171.3 39%
Commercial 50.1 11% Woods 48.4 11%
TOTAL AREA 444.4 100%
Floodplain Reconnection Approach Regenerative Design
Pre-restoration
Floodplain Reconnection Approach Regenerative Design
Desired Outcomes & Goals Outcomes
Increase Canopy Recharge Groundwater Extend Base Flows Slow Flow/Velocity Wetland Hydrology
Increase Contact with Benthos Increase and Retain Carbon Inputs
Towson Run Tributary Baltimore County, Maryland
Goals establish long-term, stable
channel geometry reduce sediment yield improve water quality
capitalize on opportunities for aquatic and riparian habitat
enhancement
Effects on Downstream Hydrology & Channel Hydraulics
reduce peak discharges across a range of smaller storms
reduce depth increase roughness wetted perimeter
shear stress and velocities
Peak Discharges 10-year - 671 cfs (HydroCAD) 2-year - 330 cfs (HydroCAD) Discharge -3.6 inch runoff
event - 44 and 74 cfs
Floodplain Reconnection Approach Regenerative Design
Desired Outcomes & Goals
Hydraulics – transport of water in the channel, on the floodplain and through sediments
reduce peak discharges across a range of storms reduce depth increase roughness increase wetted perimeter hydraulic radius reduce ear stress and velocities
Biology – biodiversity and the life histories of aquatic and riparian life
Velocity/depth diversity – 89% slow and shallow 11% fast and shallow, and slow and deep
Velocity/depth diversity – 67% slow and shallow 29% slow and deep 2% fast and shallow 1% fast and deep
MBSS Stream Habitat Assessment
Existing Conditions Towson Run, Baltimore County, MD
Proposed Conditions Towson Run, Baltimore County, MD
MBSS Stream Habitat Assessment
increased groundwater elevations maintenance of baseflow velocity/depth diversity
Reduce Vulnerability
Rethink Management
Resilient Approaches
What are your lessons learned and thoughts on ways forward?
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