Page 1

Big Trees in the City: Suspended Pavement Urban Trees Trees, Urban Soils Soils, Stormwater Management September 30, 2010

I. Ecological challenges in the urban environment II. Rethinking utilities III. How do we grow big trees? IV. Silva Cell case studies V. Integrating trees, soil & stormwater VI. Next steps

AN INTEGRATED BLUE+GREEN FUTURE FOR OUR CITIES

“Where is the water going Dad?”


L. Peter MacDonagh, ASLA, ISA, RHS, LEED AP Director of Science & Design

Kestrel Design Group, Inc. Adj Faculty Arch Adj. Arch. & Land. Land Arch Arch.

Univ. of Minnesota

Natural Areas

Agriculture

Suburban

City

Science + Design

Primarily Recharge Not Discharge Prairies often grade imperceptibly into savannas, oak woodlands, and/or wetlands (From: Packard and Mutel, Eds, 1997)

TTypical i lC Cross-Section S ti off W Wetland, tl d P Prairie, ii Savanna (Ingels, 1989)


Green Infrastructure “Avoided Avoided Gray Infrastructure Costs Costs”:: Mayor RT Rybak Green Infrastructure to Reduce Gray Stressors and Improve Blue Quality 1st inch of Rain = 90% Water Quality Solution

GREEN Infrastructure

GRAY Infrastructure

RUN OFF the Landscape

BLUE Infrastructure

RECHARGE the Landscape

How can we RECHARGE our landscape?

Wet the Uplands……

Does Green Infrastructure Work? Recharge v. Discharge

Source: Patrick Graham, Marian Kim. Evaluating the Stormwater Management Benefits of Green Roofs Through Water Balance Modeling, 2003.


Urban At-Source Stormwater Control

Green Walls/Living Walls

N t l Analog Natural A l G Green Roof R f Large Urban Trees Cisterns

Pervious Paving MORE & BIGGER CONCRETE PIPES

Where Can Ecological Services Happen? EVT Cooling? Habitat? Hydrologic Balance?

50’200’

30’50’


Rethinking g Utilities Large deciduous trees as “Green Infrastructure”

“A 30 inch DBH tree provides 70 times the ecological services of a 3” DBH tree.” Dave Nowak USDA Forest Service Co-Author of i-Tree

(Urban, 2008, Up By Roots)

Stormwater Benefits of Trees The amazing baobab [wiki] (Adansonia) or monkey bread tree can grow up to nearly 100 feet (30 m) tall and 35 feet (11 m) wide. Their defining characteristic: their swollen trunk are actually for water storage – the baobab tree can store as much as 31,700 gallon (120,000 l) of water to endure harsh drought conditions (http://www neatorama com/2007/03/ (http://www.neatorama.com/2007/03/ 21/10-most-magnificent-trees-in-theCombination Tree & Cistern! world/).

Teapot baobab, Madagascar (Image credit: Gilles Croissant)


Stormwater & Urban Trees • How Can Trees Handle the Water? Rate? Volume? Quality? • 1) Static Storage within the Media Volume • 2) Water Droplet Interception by Canopy • 3) EVT of Media borne Water p Soil • 4)) Infiltration of Water into Deep

Static Storage Within the Media • • • •

Abundant Mature Research Accepted Volumetric Quantities R li bl M Reliable Modelling d lli C Criteria it i Numerous Modelling Choices: Structural Soil (Muddy Rock), Amsterdam Soil (Dirty Sand), Raingarden Mixes, Loams (Garden Soil), Compacted (Dirt)


Soils: For Stormwater Storage g & Tree Growth 50:25:25 Saturation Point

Field Capacity

Micro-pores

Wilt Point

Macro-pores

Water movement is highly dependent on soil structure and soil ped retention (Urban, 2008, Up By Roots)

Stormwater Storage in Structural Soil

40% stormwater storage >24� per hour drainage rate

Stormwater Storage in Amsterdam Soil

30% stormwater storage >16� per hour drainage rate


Stormwater Storage in Compacted Soils…….. Soils

5% stormwater storage 0.1” per hour drainage rate

Stormwater Storage in Loam Soils…………. Soils

20% stormwater storage >4” per hour drainage rate

How Do We Grow Big g Trees & Manage g Stormwater? Provide adequate usable soil volumes in the built environment


Canopy y Interception • • • •

Significant & Developing Research Reliable Modelling Criteria Li it d M Limited Modelling d lli Ch Choices i Limited Number of Tree Species Modelled: Planes, Hackberries, Crabapples, Red Oak


Estimated Value of Tree Canopy py Interception p Minneapolis Streetscape Study, 2003-2005 16” DBH Hackberry

12” DBH Red Oak

8” DBH Crab Apple

Annual Interception: - 8,543 street trees are Elms >30” DBH, representing 4.46% of the total Minneapolis street tree population. -These These 8,543 8 543 trees provide pro ide 30 30.75% 75% of the annual stormwater interception of the entire street tree population – 2,058,500 cubic feet/47.26 acre feet, or 241 cubic feet p per tree p per yyear. (McPherson et al 2005) Co-Author of i-Tree

Estimated Value of Stormwater Interception Benefits of Large Trees Stormwater Interception by Hackberries versus Age of Tree

Gal of s stormwater interception per ye ear

Gallons of Interception/Year

Tree Age

Source: McPherson et al 2006


Stormwater Interception Volumes 2” Caliper Jacaranda versus 22” DBH Plane Tree

Source: Based on data from McPherson et al 2003

Estimated Economic Value to Stormwater Of Benefits of Large Street Trees American Elms Tree size DBH (cm) 38 114

Stormwater Interception cubic DBH meters/ Gal/tree/ (inches) tree/yr yr cf/tree/yr 15 5.4 1,427 191 45 63 16,640 2,225

-American Elms: 9 9.9% 9% of total street trees -3142 total elms >36” DBH -Elms >36” DBH = 2.6% of total street tree population (total street tree population = 120,676 trees) -Elms >36” >36 DBH provide 30 30.75% 75% of total street tree stormwater benefits (total tree stormwater benefits = 447,500 Ccf)

Source: Minneapolis Municipal Tree Resource Analysis, McPherson et al, 2005, and personal communication


Large Trees – How Large? The Quinault Lake red cedar (left) is the largest g known western red cedar in the world with a wood volume of 500 cubic meters. It is located near the northwest shore of Lake Quinault north of Aberdeen Aberdeen, Washington.(http://purpleslinky.com/triv ia/science/worlds-tallest-and-largesttrees)

Tree EvapoTranspiration • Very Limited Limited, Early Research on Trees • Most Complete Research Confined to EVT of Crops • Few Accepted Tree Studies • Limited Reliable Modelling Data p • Numerous Data Gaps


Infiltration of Water to Deep Soil • Well Accepted Mature Research • Technical & Financial Difficulties Hinder Reliability in Urban Hardscapes

Soil Filtering Bioretention Soil Mix: 65% sand, 20% compost, 15% clay silt Cumulative percent removal by depth L b t /fi ld summary Laboratory/field Soil Depth

Cu Copper

Pb Lead

Zn Zinc

P Phosphorous

TKN Keldahl nitrogen

12”

90

93

87

0

37

24”

93

99

98

73

60

36”

93

99

99

81

68

Data on bioretention removal rates of pollutants such as ammonium and total nitrogen is variable, so has not been included here. Adapted from Prince George’s County Bioretention Manual


Urban Design g Options p for Stormwater Treatment 1st Gallon Costs Rate, Water Quality and Water Quantity Design Goals 1. Increase volume & time that water is held at the site using tree soil volumes 2. Increase canopy size & reduce water volume falling to ground plane 3 Reduce 3. R d pollutant ll t t lload d & water t ttemperature t using i soilil as a filt filter & a cooler l 4. Infiltrate & use tree evapo-transpiration to reduce surface runoff volume & cool air temperatures $2.00 to $2.50

Central Library Minneapolis, MN

$28 to $35

Central Library Minneapolis, MN

$6 to $8

The Queensway Toronto, ON

Suspended Pavement Research Study: Trees & Stormwater Toronto, ON (Cooperative between Ryerson University & University of Minnesota)


Suspended Pavement Research Study: Trees & Stormwater Toronto ON (Cooperative between Ryerson University & University of Minnesota) Toronto,

Perforated distribution pipe is installed to bring water from the catch basin through the Structural Cell system

Case Study: y Trees & Stormwater Olympic Village Bike & Pedestrian Link, Vancouver, BC

Aggregate d paving i and

Silva Cell decks and geotextile Silva Cells frames and soil Setting on Compacted SubBase


Case Study: Trees & Stormwater Olympic Village Bike & Pedestrian Link, Vancouver, BC

Silva Cells provide the required soil volume to grow large shade trees adjacent a seawall and promenade. Stormwater runoff (1�/72 hour) to Vancouver Bay volume is reduced & quality is improved.

Case Study: y Trees and stormwater Marquette & 2nd Avenue, Minneapolis, MN

5.5 5 5 acres of Impervious Surface Capacity for 1�/24 1 /24 hour storm -Small storm impact to Mississippi River reduced


Washington State Department of Ecology Silva Cell Received General Use Designation for Western Washington State in September 2009: Functional Equivalent of a Raingarden under Pavement

Tree Roots: How Deep?

The Tree of Ténéré or L’Abre du Ténéré was the world’s most isolated tree – the solitary acacia, which grew in the Sahara desert in Niger, Africa, and was the only tree within more than 250 miles (400 km) around. This tree was the last surviving member of a group of acacias that grew when the desert wasn’t as dry. When scientists dug a hole near the tree, they found its roots went down as deep as 120 feet (36 m) below to the water table!

The Tree of Ténéré in the 1970s (Image credit: Peter Krohn)


Tree Roots & Soil Macropores p Oxygen-rich soil volumes support root growth

Saturation Point

Field Capacity

Wilt Point

Tree Roots in Mollisols….

Tree Roots in Entisols…..


Tree Roots and Pipes Number of Intrusions

Intrusion Number

Feet

Courtesy of Stahl

Typical yp US Street Tree Unable to make environmental contributions; but able to cause damage in search for adequate soil

Moll: 13 years - Poor drainage - Short lifespan - High replacement costs - Root heaving of sidewalks - Root intrusions into Utilities - Limited ecological function

Moll 1997; Urban, 2001; Stahl, 2003


How Can We Grow Big Trees? St t l SSoil? Structural il?

Here’s the Answer: 1994

Rock

(Urban, 2008, Up By Roots)

Tree pit soil 115 cf

Structural Soil 200 cf

Structural Soil 1994-1998 What Happened?

Trees in open soil trench

(Urban, 2008, Up By Roots)

Trees in Structural Soil


Structural Soil 1994 – 2006 What Happened?

Year 12

Year 12

Structural soil - 350 cubic feet / tree Provides: 70 cubic feet / tree actual soil Plus 55 cf soil in tree pit Total soil 125 cf / tree

Soil - 275 cubic feet / tree in open planter (Urban, 2008, Up By Roots)

How Can We Grow Big Trees? Value of the soil in structural soil Large (4.87) structural soil and Small (1.00) l loam soilil are equall amounts t off soil. il

Large structural soil: 1 9 c.f. 1.9 cf (0.054 c.m.)

Small Loam Soil: 0 39 c.f. 0.39 cf (0.011c.m.)

Large Loam Soil: 1.9 c.f. (0 054 c.m.) (0.054 cm)

Conclusion: Structural Soil provides 21% of the Value of Loam Per Cubic Unit OR Needs a 4.87 Multiplier To Equal the Same Per Cubic Unit Measure

Source: Growth response of Ficus benjamina to limited soil volumes and soil dilution in a skeletal soil container study. Loh, Grabowsky, and Bassuk. Urban Forest, Urban Green, 2 (2003)


How Can We Grow Big Trees? Value of the soil in structural soil Large (4.87) structural soil and small (1.00) loam soil are equal amounts of soil. 1 72 Times 1.72 Ti Height H i ht Diff Difference

PLANT HEIGHT VS. DAYS OF STUDY

Days of Study

3 0 Times Leaf Count 3.0

LEAF COUNT VS. DAYS OF STUDY

Days of Study

Is s Loam oa Always ays tthe e Best est C Choice? o ce ……..There are Exceptions: J k Pi Jack Pines; Bristlecone B i tl Pi Pine; Limber Pines; Colorado Blue Spruce OFTEN Grow Best in Rock Scree & Sand Rock, However, None of These Trees Are Street Trees OR Even Urban Trees


Bartlett Tree Lab – Urban Plaza Study y Urban Plaza at 14 Months

E. Thomas Smiley et al 2009, 2010; Bartlett Tree Laboratory

Bartlett Tree Lab – Urban Plaza Study y Urban Plaza at 2.5 Years

E. Thomas Smiley et al 2009, 2010; Bartlett Tree Laboratory


Bartlett Tree Lab – Urban Plaza Study y Urban Plaza at 3.5 Years

E. Thomas Smiley et al 2009, 2010; Bartlett Tree Laboratory

Bartlett Tree Lab – Urban Plaza Study y Urban Plaza at 4+ Years

E. Thomas Smiley et al 2009, 2010; Bartlett Tree Laboratory


Bartlett Tree Lab – Urban Plaza Study y Urban Plaza at 5.5 Years

E. Thomas Smiley et al 2009, 2010; Bartlett Tree Laboratory

Bartlett Tree Lab – Urban Plaza Study Urban Plaza at 6.5 6 5 Years


Supporting pp g Tree Function with Large g Soil Volumes Soil volumes for root growth

“Id l” C “Ideal” Conditions diti

Grabosky, Trowbridge and Bassuk (2002)

How Large g the Soil Volume? How Large g the trees? Provide large soil (Sandy Loam; <4”/hour) volumes to Manage Stormwater Runoff Volume & Quality

240 cf rain water 4250 sf. drainage area (.75” rain) 160 cf rain water 2850 sf. drainage area (.75” rain)

80 cf rain water 1420 sf. drainage area (.75” rain)

(Urban, MacDonagh et al, 2008)


Case Study: Large Trees Under Suspended Pavement Charlotte, NC Charlotte Over 170 Trees Planted in 1985 in Suspended Pavement System

E. Thomas Smiley et al 2009, 2010; Bartlett Tree Laboratory

Case Study: Large Trees Under Suspended Pavement Charlotte, NC: Trees are flourishing 25 years after planting Willow Oak (Quercos phellos): Per Tree Averages: -Average height: 44 feet -Average DBH: 16â&#x20AC;? -Average soil volume: 700 ft3 (not counting soil sharing) -167 of 170 Trees Survived to be Included in Study - Low Standard of Care: 5 Year Pruning g Intervals NO Supplemental Water, Mulching High Limbing 15â&#x20AC;&#x2122;+


Case Study: Large Trees Under Suspended Pavement Bethesda, MD: Trees are flourishing 25 years after planting

Plane (Platanus x “Bloodgood”); Bloodgood ); Poor Mans Tree (Zelkova serrata); American Elm Various CV (Ulmus CV) : Per Tree Averages: -Average height: 40 to 44 feet -Average DBH: 14” to 20” -Average soil volume: 400 ft3 (not counting soil sharing) Very High Standard of Care: 1 Year Pruning Intervals Supplemental Water, Mulching

Cost Decisions Consider both cost and value

Trees and T d lilights ht h have equall costt – but b t a tree t increases in value as it grows.


$500 $450 $400 $350 $300 $250 $200 $150 $100 $50 $0

Total Benefits

Stormwater Interception

End of 40 0 Year Lifecycle Cosst SStudy Period

Value of Averrage Annual Benefitts in $

Tree Without Silva Cells: Benefits vs. Year

Energy Savings

VALUE OF URBAN TREE BENEFITS VS. TIME:

Property Value

Air Quality

Carbon Dioxide Net Storage

0

20

40

Total Benefits over 60 years: $1,563.45 Total Benefits over 40 years: $1,084.78 Net Lifecycle Cost over 40 years: $2,901.43

Tree In Compacted Soil Estimated Lifespan Of 13 Years

60

Year

Vs.

$500 $450 $400 $350 $ $300 $250 $200 $150 $100 $50 $0

Total Benefits Stormwater Interception

End of 40 Year Lifecycle Cost E Study Pe eriod

Value of Average Ann nual Benefits in $

Tree With Silva Cells for Stormwater: Benefits fi vs. Year

0

20

40 Year

Tree With Silva Cells + Bioretention Soil – Estimated Lifespan Of 60 Years

Energy Savings Property Value Air Quality Carbon Dioxide Net Storage Bioretention

60

Stormwater Utility Credit

Total Benefits over 60 years: $19,197.60 Total Benefits over 40 years: $10,733.65 Net Lifecycle Cost over 40 years: $-1,331.74

Brugge, Belgium

Urban Trees That We Want……………….


What Do People Living in Cities Want? Big Trees

Li Lincoln l C Center t (2 year S Suspended d dP Pavementt IInstall) t ll)

What Do Public Officials Want? Happy Constituents & Strong Tax Base

Bethesda, MD (25 year Suspended Pavement Install)


What Do Landscape Architects Want? Draw Pictures & Grow Large Trees - to Hug

DEPTH 23â&#x20AC;&#x2122; Photo Credit: Orjan Stahl

What Do Civil Engineers Want? Stormwater Infrastructure that Will Last Beyond Their Retirement


Urban Trees That Landscape Architects Draw Draw………………… Mister/Ms Client………Imagine if You Will…………….

Urban Trees That We Get • In Structural Soil……….

Staten Island, 16 years after installation

Urban Trees That We Get • In Amsterdam Soil…….

Rose Kennedy Greenway, North End Parks, 2 years after installation


Urban Trees That We Get: In Compacted Soils………….

Trees are 8 years old

“If the Trees Die, Landscape Architecture is NOT Art……………..” JAMES URBAN, FASLA, PRESIDENTIAL MEDAL AWARDEE

“Nor Can It Manage…………… Stormwater”


Urban Trees That We Get in Loams Under Suspended S Pavement…………… Lincoln Center Center, NY 2 Years Old: 6” Caliper 30+” twig growth in 2010, no significant transplant shock

Urban Trees We Get in Loam Under Suspended Pavement Pavement………….. Downtown Bethesda, MD 25 Years Old Success Rate Not Tabulated


Urban Trees That We Get in Loams Under Suspended Pavement…………… Downtown Charlotte, NC 25 Years Old 98% Success Rate

Next Steps p for Municipalities p Soil volume targets and stormwater treatment goals Emeryville California (2008) Emeryville, Designated Small Sized Species Trees: 400 cubic feet per tree Designated Medium Sized Species Trees: 600 cubic feet per tree Designated Large Sized Species Trees: 1,200 cubic feet per tree

Charlotte North Carolina Charlotte, All Trees: 1,000 cubic feet of loam per tree

Toronto, Canada (2009) Individual Tree Pits: 1100 cubic feet of loam per tree Multiple Trees Tree Pits: 550 cubic feet of loam per tree Stormwater: Sites must retain all runoff from "small design" rainfall events (typically .19," or 5 mm) through rainwater reuse, on-site infiltration, and evapotranspiration.


Green Infrastructure at Scale Let’s Make Livable Cities: Waterfront Toronto: 2100 Acres On Lake Ontario; Largest Waterfront Project in the World

Trees / Rain Water and Silva Cells Urban Streets

-16 trees per acre capture 1”/24 hour storm in: Soil -16 trees @ 16” DBH capture 2”/24 hour storm in: soil, EVT, & Interception

Evapotranspiration

Pervious surface

Phase 1 Installed: 1,300 trees All Phases: 16,800 trees Imperviou i s surface

Structural Cells and Water Storage

Infiltration

LR

Thank you! y Audience questions & comments

“Top p 10 Green Building g Product of 2009,” , Architectural Record

“Top 10 Green Building Product of 2009,” Building Green

“Top 15 Green Building Product of 2009,” Environmental Design + Construction

“New & Noteworthy Product,” Architectural Products

Upcoming p g Speaking p g events: ASCE ((October 29 in Las Vegas, g NV), ) GreenBuild (November 17-19 in Chicago, IL), & CSLA (August 19-21 in Edmonton, AB)


Contact: L. Peter MacDonagh Kestrel Design Group Group, Inc Inc. pmacdonagh@tkdg.net pmacdonagh@tkdg net peter@deeproot.com (952) 928-9600 Cell (612) 730 730-4381 4381 “Dad. We Need Big Trees”

Green Infrastructure at Scale • Largest extensive vegetative roof installed on an existing sports building. • First extensive vegetative roof on an arena. • Fifth-largest g extensive vegetative roof in North America. • Tenth-largest g extensive vegetative roof in the world


Green Infrastructure at Scale Letâ&#x20AC;&#x2122;s Make Livable Cities: Minneapolis, MN

Target Center Arena Green Roof -115,000 sf/1 million gallons per year captured

How Will We Meet Our Storm Water Management Regulations? G Green Infrastructure I f t t

U f d dF Unfunded Federal d lM Mandates: d t -Stormwater Utility Fees (there are over 1,400 existing stormwater utilities in the U it d St United States, t and d more b being i proposed d every week). - Soil volume targets: 600 cff lloam per ttree iin C Connected t d ttrenches h 1200 cf loam per tree in Individual Pits - Healthy, viable, long-living trees in the built b ilt environment i t


EPA Green Grants City of Utica, NY

The New York State Environmental Facilities Corporation administered an EPA grant for $700,000 for street tree planting. Approximately 20% new trees will use Silva Cells. Silva Cells were installed June 2010.


Where Do We Go From Here? EPA Section 438, and beyond

“Any development or re-development project involving a Federal facility with a footprint that exceeds 5,000 square feet shall… maintain or restore, to the maximum extent technically feasible, the predevelopment hydrology of the property with regard to the temperature, rate, volume and duration of flow.”

Soil S il volume l targets t t will ill prioritize i iti the th critical iti l water-retaining t t i i and d evapotranspirating functions of soil and trees in the built environment.

Silva Cells: Proven Technology gy 2006 – Present: Over 130 installations


95th Percentile Rainfall Event for Select U.S. Cities Green infrastructure managing small, daily rainfall events

City

95th Percentile Event R i f ll Total Rainfall T l (in) (i )

City

95th Percentile Event R i f ll Total Rainfall T l (in) (i )

Atlanta, GA

1.8

Kansas City, MO

1.7

Baltimore, MD

1.6

Knoxville, TN

1.5

Boston, MA

1.5

Louisville, KY

1.5

Buffalo, NY

1.1

Minneapolis, MN

1.4

Burlington, VT

1.1

New York, NY

1.7

Charleston, WV

1.2

Salt Lake City, UT

0.8

Coeur Dâ&#x20AC;&#x2122; Alene Alene, ID

07 0.7

Phoenix AZ Phoenix,

10 1.0

Cincinnati, OH

1.5

Portland, OR

1.0

Columbus, OH

1.3

Seattle, WA

1.6

Concord, NH

1.3

Washington, DC

1.7

Denver, CO

1.1

Hirschman, David and John Kosco. 2008. Managing Stormwater in Your Community: A Guide for Building an Effective Post-Construction Program, Center for Watershed Protection, www.cwp.org/postconstruction.


URBAN TREE LIFECYCLE COSTS FOR A 40 YEAR STUDY PERIOD, BASED ON TYPICAL COSTS AND BENEFITS FOR MINNEAPOLIS, MN Lifecycle Costs and B Benefits fit over 40 years

Installation Costs

Tree Without Sil Cells: Silva C ll Estimated Lifespan 13 years $3,000

Total Benefits

$1,084.78

Total Maintenance Costs

$586.21

Removal Costs

$400

Net Lifecycle Cost

$2,901.43

Notes for Tree Without Sil Cells Silva C ll

Tree with Sil Cells: Silva C ll Estimated Lifespan 60 Years $8,000

Estimated at $1,000 per tree, i t ll d 3 ti installed times over a 40 year study period Includes savings from $10,733.65 reduced building energy costs, stormwater interception increased interception, property values, and the net value of carbon sequestration in the tree.1 Includes estimated costs for $1,401.91 pruning pest and disease pruning, control, infrastructure repair, irrigation, cleanup, liability and legal costs, and administration costs.2 Estimated at $200 per tree, tree 2 $0 times over a 40 year study period $-1,331.74

Notes for Tree With Silva Cells

Estimated at $8,000 per tree, i t ll d 1 ti installed time over a 40 year study t d period Includes savings from reduced building energy costs, stormwater interception, increased property values the net value of carbon values, sequestration in the tree,1 bioretention3, and stormwater utility fee credit4. Includes estimated costs for pruning, pest and disease control control, infrastructure repair, irrigation, cleanup, liability and legal costs, administration costs,2 and bioretention maintenance. No removal necessary because estimated tree life span is longer than study period

1

Values are based on values documented by i-tree, a peer-reviewed street tree management and analysis software tool for urban forest managers that uses tree inventory data to quantify the dollar value of annual environmental and aesthetic benefits of trees, produced by the i-Tree Cooperative (“the Cooperative”), consisting of the USDA Forest Service, Davey Tree Expert Co., National Arbor Day Foundation, Society of Municipal Arborists and International Society of Arboriculture. 2 Values are based on values documented by McPherson, E.G., J.R. Simpson, P.J. Peper, S.E. Maco, S.L. Gardner, S.K. Cozad, and Q. Xiao.. 2006. Midwest Community Tree Guide: Benefits, Costs and Strategic Planting PSW-GTR-199. USDA Forest Service, Pacific Southwest Research Station, Albany, CA 3 Bioretention storage for 1 tree with 80 cells, capturing 1” rain event in Minneapolis (approximately 15” per year on 630 s.f. = 4905 GAL per year) based on value of $0.027/GAL of storage per McPherson et al, 2005: 4905 GAL/year x $0.027/ GAL /year = $132/year. 4 Stormwater utility credits for 1 tree capturing runoff from 630 s.f of impervious surface = $26.60 per year

Why is it so Hard to Believe that Urban Trees Grow Best in Loam? Why are Almost ALL of our State Champion Trees Growing Best in Loams?


Stormwater Interception 8” DBH Declining Elm 8

4” DBH Declining Oak 4

Champion Savanna Tree Growing in Loam… Loam • Burr Oak, Funks Grove, IL

Champion Forest Tree Growing in Loam…. Loam • Sugar Maple, Funks Grove, IL


About Us & Our Team Stormwater experts, designers, engineers, academics

The DeepRoot Mission To restore ecosystem y services to the built environment by integrating trees, soil and stormwater. Our Partners The Kestrel Design Group James Urban, FASLA Engineering Partners International, LLC Stantec Innova Engineering With significant contributions by: E. Thomas Smiley, PhD Bartlett Tree Research Laboratory

“Where is the water going Dad?”

Ecological g Challenges g How can green utilities play a role?

“Stormwater Control Measures that harvest, infiltrate, and evapotranspirate stormwater are critical to reducing the volume and pollutant loading of small storms.”1 “Nearly all of the associated problems result from one underlying cause: loss of the water-retaining and evapotranspirating functions of the soil and vegetation in the urban landscape.” 2 “The undervaluing of soils is one of the singular failings of the conventional development approach.”3 1. EPA commissioned report – Urban Stormwater Management in the United States 2008 2. Ibid. 3 Sustainable 3. S t i bl Sit Sites IInitiative iti ti – Guidelines G id li and dP Performance f B Benchmark h kD Draft ft 2008 (ASLA (ASLA, 2008)


An Upside p Down World Associated problems with ultra-urban development

- Urban heat island effect - Non point-source pollution - Flooding - Failing urban canopy - Compromised air and water quality - Reduced home and business values - Psychological stress

Images from Fairfax County Park Authority, Fairfax VA

An Upside Down World Th Cl The Clean W Water t A Actt & NPDES NPDES: Ph Phase 1 1, 2 2, 3 (2012) (2012); TMDL mitigation iti ti complete l t 13 years after ft TMDL Identification

HARD PART Non--Point Source Pollution Non

EASY PART Point Source Pollution

Cuyahoga River Fire, 1969 Resulted in the Clean Water Act StarTribune NASA, Goddard Space Center; 2001


Impervious p Surfaces Quality and rate problems

Predevelopment p Postdevelopment

Streams and Rainstorms Higher and more rapid peak discharge Small storm

Streamflo ow rate

More runoff volume Lower and loss rapid peak Gradual recession

Higher base flow

Time

Adapted From: Protecting Water Quality in Urban Areas. Best management Practices for Dealing with Storm Water Runoff from Urban and Suburban Developing Areas of Minnesota. MPCA 2000.

Gray y & Green Infrastructure Conflicts Root constriction

Where do the roots go? Wherever there are macropores.


Pipes p After 11 Years Roots will interfere with pipes if they have no other options

Stahl et al.; 2003

Dismantling g PVC Pipeâ&#x20AC;&#x2122;s p Elastometric Joints Roots will interfere with pipes if they have no other options

Stahl et al.; 2001

Stahl et al al.;; 2003


A Tree Root Tip p can Develop p a Pressure of 15 bars Elastometric seal on a pipe resists pressure of 3-5 bars

Acorns g growing g on Geo-textile Press on Steel Plate 15 bars Nutrient Rich Solution

Stahl et al.; 2003

Tree Roots and Pipes Repair Impacts


Tree Roots and Pipes Repair Impacts

Courtesy of Stahl

23â&#x20AC;&#x2122; deep repaired PVC

Bring g The Functionality y of the Forest to the City y The Silva Cell

Basic Applications: Parking lots; parking lay-bys; plazas and promenades; green walls; green roofs & break-out zones

Image courtesy of Sharp & Diamond Landscape Architects


Water Harvesting g in Urban Spaces p Multiple options for getting stormwater in to the Silva Cell system

Pervious pavers

Trench drains

Catch basins Grate with catch basin and distribution pipe

Case Study: y Marquette q & 2nd Avenue Cost savings

Rather than spending $3.5M to enlarge the storm sewer system capacity, the City of Minneapolis spent $1.5M on Silva Cells to meet their stormwater treatment goals.

Street trees in loam with suspended pavement  

“Where is the water going Dad?” UrbanTrees UrbanSoils StormwaterManagement Urban Trees, Urban Soils, Stormwater Management I. Ecological cha...

Read more
Read more
Similar to
Popular now
Just for you