VolumeVolume--Based Design and Based Design and G fG f

VolumeVolume--Based Design and Based Design and G fG fGreen InfrastructureGreen Infrastructure

Andy ReeseAndy ReeseGreen InfrastructureGreen Infrastructure

Andy ReeseAndy ReeseAndy Reese Andy Reese PE, LEEDPE, LEED--APAP

AMEC Earth & Environmental, Inc.AMEC Earth & Environmental, Inc.

Andy Reese Andy Reese PE, LEEDPE, LEED--APAP

AMEC Earth & Environmental, Inc.AMEC Earth & Environmental, Inc.

http://www stormh2o com/september 2009/volume based hydrology aspxhttp://www.stormh2o.com/september-2009/volume-based-hydrology.aspx

Google it !!Google it !!

Urban Stormwater Paradigm ShiftsUrban Stormwater Paradigm ShiftsUrban Stormwater Paradigm ShiftsUrban Stormwater Paradigm Shifts6. “Oh… and don’t

pollute either”1. “Run it in ditches” 6. “Oh… and don’t

pollute either”1. “Run it in ditches”

7. “It’s the ecology stupid!”

2. “Run it pipes”7. “It’s the ecology

stupid!”

2. “Run it pipes”

stupid!

8. “Water is water is

3. “Run it in stormwater pipes”

stupid!

8. “Water is water is

3. “Run it in stormwater pipes”

8. W e s w e swater...shed”

9 “G & b it”

4. “Keep it from stormwater pipes”

8. W e s w e swater...shed”

9 “G & b it”

4. “Keep it from stormwater pipes”

9. “Green & bear it”p p

5. “Just don’t cause a flood”

9. “Green & bear it”

10 “Back to the Future”

p p

5. “Just don’t cause a flood”flood” 10. Back to the Futureflood”

Various ApproachesVarious ApproachesVarious ApproachesVarious Approaches Low Impact

Development Sustainable

Developmentp Multi-objective

Corridors

p Smart Growth Eco-Friendly Design

Integrated Site Design Better Site Design

Zero Discharge Smart Site Development

Green Infrastructure Conservation Design

New Urbanism LEED designs

Green Infrastructure

Green Building Green Technology

i i d i

Water sensitive urban design

Context sensitive design

New EPA Direction New EPA Direction –– Numeric Numeric d dd d

New EPA Direction New EPA Direction –– Numeric Numeric d dd dStandardStandardStandardStandard

Retain all runoff up to a specified percentile Retain all runoff up to a specified percentile rainfall eventrainfall event 85% to 95%85% to 95%rainfall event rainfall event –– 85% to 95%85% to 95%

OnOn--site practices must either infiltrate, site practices must either infiltrate, evapotranspire or reuse required volume ofevapotranspire or reuse required volume ofevapotranspire, or reuse required volume of evapotranspire, or reuse required volume of stormwaterstormwater

MightMight require impervious area treatmentrequire impervious area treatment MightMight require impervious area treatment require impervious area treatment numbersnumbers

Currently being implemented through:Currently being implemented through: Currently being implemented through:Currently being implemented through:•• Section 438 of EISA, Washington DC MS4 permit, Section 438 of EISA, Washington DC MS4 permit,

Chesapeake Guidance documentChesapeake Guidance documentChesapeake Guidance documentChesapeake Guidance document

A rational framework for understanding…A rational framework for understanding…

biggest flows biggest flows to considerto consider

Floodplain Mgmt.Floodplain Mgmt.

Bankfull

to considerto consider

most most destructivedestructive

flowsflows

Flooding ProtectionFlooding ProtectionBankfull

most most erosiveerosiveflowsflows

Erosion ControlErosion Control

Q criticalmost most

pollutedpollutedflowsflows

Water QualityWater Qualityflowsflows

RetainedRetainedflowsflows RetentionRetention

ExtremeFlood Protection

FloodplainManagement

Overbank FloodProtection

Overbank FloodProtectionThis looks like the use of Green InfrastructureThis looks like the use of Green Infrastructure

Channel ProtectionChannel ProtectionChannel Protection

Water QualityWater Quality

Water QualityRetentionRetention

For the regulator community and thusFor the regulator community and thusFor the regulator community and thusFor the regulator community and thusFor the regulator community, and thus For the regulator community, and thus for us, this sort of boils down to:for us, this sort of boils down to:

For the regulator community, and thus For the regulator community, and thus for us, this sort of boils down to:for us, this sort of boils down to:

“For“For our programour program thethe“For“For our programour program thetheFor For our programour program the the

right volumeright volume must bemust be retainedretained

For For our programour program the the

right volumeright volume must bemust be retainedretained

right volumeright volume must be must be retainedretained

on site”on site”

right volumeright volume must be must be retainedretained

on site”on site”on site on site on site on site

Or treated… ok, or on another site… ok, or pay upOr treated… ok, or on another site… ok, or pay up

Why should I Retain ?Why should I Retain ?Why should I Retain ?Why should I Retain ?yyyy

“…our program…”“…our program…”

What is your primary What is your primary What is your primary What is your primary driver to retain water?driver to retain water?driver to retain water?driver to retain water?

CSO reduction – as much as feasible given cost/benefit Reuse - Depends on water/alternative pricing for reuse CSO reduction – as much as feasible given cost/benefit Reuse - Depends on water/alternative pricing for reuse Water Supply – little or much depending on water

source and fate of infiltrated water Water Supply – little or much depending on water

source and fate of infiltrated water Groundwater Replenishment – mimic “nature”, replace

withdrawal, control water tableP ll i l h ll i

Groundwater Replenishment – mimic “nature”, replace withdrawal, control water tableP ll i l h ll i Pollution removal – enough to meet pollution targets

Regulatory mandate – what they tell you to do (of )

Pollution removal – enough to meet pollution targets Regulatory mandate – what they tell you to do (of

)course)course)

Why should I retain ?Why should I retain ?How much should I retain ?How much should I retain ?Why should I retain ?Why should I retain ?How much should I retain ?How much should I retain ?How much should I retain ?How much should I retain ?How much should I retain ?How much should I retain ?

“ the right volume ”“ the right volume ”…the right volume……the right volume…

What kind of volumes are we What kind of volumes are we lki blki b

What kind of volumes are we What kind of volumes are we lki blki btalking about? talking about? talking about? talking about?

1.1. Federal Facilities & Ches. Bay Federal Facilities & Ches. Bay –– 95% storm95% storm22 Washington DCWashington DC –– 90% storm90% storm2.2. Washington DC Washington DC 90% storm90% storm3.3. W. Virginia W. Virginia –– 85% storm (85% storm (≈≈1”)1”)

h i h h f fi fl h fi “ ”h i h h f fi fl h fi “ ”4.4. Then a mishmash of first flush, first “X” Then a mishmash of first flush, first “X” from DCIA, flow duration, etc.from DCIA, flow duration, etc.

95% Storm Event95% Storm Event95% Storm Event95% Storm Event

City 

95th Percentile Event Rainfall 

Total (in)  City 

95th PercentileEventRainfall Total (in) 

Atlanta GA 1 8 Kansas City MO 1 7City 

95th Percentile Event Rainfall 

Total (in)  City 

95th PercentileEventRainfall Total (in) 

Atlanta GA 1 8 Kansas City MO 1 7Atlanta, GA  1.8 Kansas City, MO  1.7Baltimore, MD  1.6 Knoxville, TN  1.5Boston, MA  1.5 Louisville, KY  1.5

Buffalo NY 1 1 Minneapolis MN 1 4

Atlanta, GA  1.8 Kansas City, MO  1.7Baltimore, MD  1.6 Knoxville, TN  1.5Boston, MA  1.5 Louisville, KY  1.5

Buffalo NY 1 1 Minneapolis MN 1 4Buffalo, NY  1.1 Minneapolis, MN  1.4Burlington, VT  1.1 New York, NY  1.7

Charleston, WV  1.2 Salt Lake City, UT  0.8

C D’Al ID 0 7 Ph i AZ 1 0

Buffalo, NY  1.1 Minneapolis, MN  1.4Burlington, VT  1.1 New York, NY  1.7

Charleston, WV  1.2 Salt Lake City, UT  0.8

C D’Al ID 0 7 Ph i AZ 1 0Coeur D’Alene, ID  0.7 Phoenix, AZ  1.0Cincinnati, OH  1.5 Portland, OR  1.0Columbus, OH  1.3 Seattle, WA  1.6Concord, NH 1.3 Washington, DC 1.7

Coeur D’Alene, ID  0.7 Phoenix, AZ  1.0Cincinnati, OH  1.5 Portland, OR  1.0Columbus, OH  1.3 Seattle, WA  1.6Concord, NH 1.3 Washington, DC 1.7Concord, NH  1.3 Washington, DC  1.7Denver, CO  1.1Concord, NH  1.3 Washington, DC  1.7Denver, CO  1.1

Example: Nashville, TNExample: Nashville, TN95% Storm 1 74”95% Storm 1 74”

Example: Nashville, TNExample: Nashville, TN95% Storm 1 74”95% Storm 1 74”95% Storm = 1.74”95% Storm = 1.74”95% Storm = 1.74”95% Storm = 1.74”

So is that theSo is that theSo is that theSo is that theSo… is that the So… is that the So… is that the So… is that the

“right volume”?“right volume”?“right volume”?“right volume”?

Nature (we think)Nature (we think)Nature (we think)Nature (we think)159 storms 1.74” ± 20%

(95% storm)

For example for B soil:For example for B soil:87% of storms no runoff87% of storms no runoff10% had 110% had 1--10% volume runoff10% volume runoff2.5% had 102.5% had 10--20% runoff20% runoff0 5% had 200 5% had 20--30% runoff30% runoff

ShiftShift

0.5% had 200.5% had 20 30% runoff30% runoff

The goal can be stated asThe goal can be stated asThe goal can be stated asThe goal can be stated ashydrologic mimicryhydrologic mimicryy g yy g y

H h i f ll didH h i f ll didHow much rainfall did nature How much rainfall did nature keep from running off?keep from running off?keep from running off?keep from running off?

OK, do that. OK, do that.

Alternative Criterion: Mimic Annual CaptureAlternative Criterion: Mimic Annual CaptureAlternative Criterion: Mimic Annual CaptureAlternative Criterion: Mimic Annual Capture50% Tree Canopy Annual Volume Capture Requirement

87% capturevs. 58% capture

Nature + ManNature + Man

Big ShiftBig Shift

Why should I Retain ?Why should I Retain ?How much should I retain ?How much should I retain ?Why should I Retain ?Why should I Retain ?How much should I retain ?How much should I retain ?What does “retain” mean and how do I do it?What does “retain” mean and how do I do it?What does “retain” mean and how do I do it?What does “retain” mean and how do I do it?

“…must retain …”

Steps to “retain” water?Steps to “retain” water?Steps to “retain” water?Steps to “retain” water?

1. The very best way is to develop in such a way that little water runs off – “Better Site Design”

99% capturevs. 66% capture

66% t66% capturevs. 96% capture

Steps to “retain” water?Steps to “retain” water?Steps to “retain” water?Steps to “retain” water?

1. The very best way is to develop in such a way that little water runs off – “Better Site Design”

2. After that has been done (or if it is too late) then look to other kinds of Green )Infrastructure controls…

3 If not possible then look for (1) flow3. If not possible then look for (1) flow through treatment, (2) off site mitigation, or (3) payment in lieu of controlsor (3) payment in lieu of controls

“retain”“retain” means… means…

Evapotranspiration (“up”)Evapotranspiration (“up”)

Alternate UseAlternate Use(“out”)(“out”)

Infiltration (“down”)Infiltration (“down”)

Steps to “Mimic Nature”Steps to “Mimic Nature”Steps to “Mimic Nature”Steps to “Mimic Nature”

0.42” vs. 1.2” Green Infrastructure capture0.42” vs. 1.2” Green Infrastructure capture

This means you getThis means you getThis means you get This means you get better mimicry at better mimicry at 35% of the G.I. 35% of the G.I.

llvolumevolume

Real World AnalysisReal World AnalysisReal World AnalysisReal World AnalysisReal World AnalysisReal World AnalysisReal World AnalysisReal World Analysis

“good science sound“good science soundgood science, sound good science, sound testing, effective criteria, testing, effective criteria,

proper constructionproper constructionproper construction, proper construction, periodic maintenance”periodic maintenance”

Generic Green InfrastructureGeneric Green InfrastructureGeneric Green InfrastructureGeneric Green Infrastructure

1. Infiltration-based BMPs• Bioretention• Porous Surfaces

2. Rainwater Harvesting and Use

Ci

InitialInitialStorageStorageVolumeVolume

• Cisterns• Rain Barrels

3 Evapotranspiration

Reduction RateReduction Rate

3. Evapotranspiration• Trees• Green roofsGreen roofs

InfiltrationInfiltration--Based BMPsBased BMPsInfiltrationInfiltration--Based BMPsBased BMPsInfiltrationInfiltration--Based BMPsBased BMPsInfiltrationInfiltration--Based BMPsBased BMPs

It can change the way we look at stormwater controls…It can change the way we look at stormwater controls…

TreatmentTreatmentBMPTreatmentBMPTreatmentTreatmentTreatment

VolumeVolume

100 mg/l100 mg/l

Treatment

40 mg/l60% removal

Treatment

40 mg/l60% removal

Infiltration

0 mg/l

Infiltration

0 mg/l

½ @ 0mg/l + ½ @ 40mg/l = 20 mg/l½ @ 0mg/l + ½ @ 40mg/l = 20 mg/l½ @ 0mg/l + ½ @ 40mg/l = 20 mg/l= “80% removal”

½ @ 0mg/l + ½ @ 40mg/l = 20 mg/l= “80% removal”

It can change our local design criteria…It can change our local design criteria…

Nashville, TN Bioinfiltration

Combination with Flow Through

Rainwater Harvesting and UseRainwater Harvesting and UseRainwater Harvesting and UseRainwater Harvesting and UseRainwater Harvesting and UseRainwater Harvesting and UseRainwater Harvesting and UseRainwater Harvesting and Use

Capture and Use (reCapture and Use (re--use)use)Capture and Use (reCapture and Use (re--use)use)p (p ( ))p (p ( ))

Key factors for success of capture and use:Key factors for success of capture and use:y py p•• Having a use for the waterHaving a use for the water

•• Being able to use the water fast enoughBeing able to use the water fast enough•• Being able to use the water…fast enoughBeing able to use the water…fast enough

•• Understanding how important not having enough Understanding how important not having enough ater isater is and ma be designing for dr ears orand ma be designing for dr ears orwater is water is –– and maybe designing for dry years or and maybe designing for dry years or

having an alternative sourcehaving an alternative source

A 1,000 sf roof will A 1,000 sf roof will deliverdeliver 65.5 65.5 l/dl/d

A 1,000 sf roof will A 1,000 sf roof will deliverdeliver 65.5 65.5 l/dl/dgal/day on averagegal/day on averagegal/day on averagegal/day on average

Farmer’s Market NashvilleFarmer’s Market NashvilleFarmer’s Market NashvilleFarmer’s Market NashvilleFarmer s Market NashvilleFarmer s Market NashvilleFarmer s Market NashvilleFarmer s Market Nashville 58,400 or 74,674 sf roof 58,400 or 74,674 sf roof

area could supply 145,000 area could supply 145,000 pp ypp ygal/mo based on rulegal/mo based on rule--ofof--thumbthumb

190,000 g/mo 190,000 g/mo medianmediandemand for irrigation demand for irrigation ––but irregularbut irregular

Supplemented by potable Supplemented by potable waterwater

Do Rain Barrels Work?Do Rain Barrels Work?Do Rain Barrels Work?Do Rain Barrels Work?

EvapotranspirationEvapotranspirationEvapotranspirationEvapotranspirationEvapotranspirationEvapotranspirationEvapotranspirationEvapotranspiration

CSS Area of NashvilleCSS Area of NashvilleCSS Area of NashvilleCSS Area of Nashville Can hold about 1.4” Can hold about 1.4”

starting drystarting dry 4” media4” media 59% annual capture 59% annual capture 25 1” C t d25 1” C t d 25.1” Captured or 25.1” Captured or

15,700 gal/yr/1,000sf15,700 gal/yr/1,000sf 112 million gallons/year 112 million gallons/year g yg y

removedremoved

Tree CanopyTree CanopyTree CanopyTree CanopyTree CanopyTree CanopyTree CanopyTree Canopy

Nashville Green Infrastructure Tree Canopy Assessment

Tree Canopy Classification

Current Tree Canopy Potential Tree Canopy

Statistics on Tree CanopyStatistics on Tree CanopyStatistics on Tree CanopyStatistics on Tree CanopyStatistics on Tree CanopyStatistics on Tree CanopyStatistics on Tree CanopyStatistics on Tree Canopy Trees intercept or evapotranspire about

60% of annual rainfall Existing tree canopy = 1,535 acres Potential tree canopy = 51,773 new

trees, 811 acres Potential volume removal 13,000

gallons per tree or 660 MG total

But in a drought… (!)

In closing:In closing:In closing:In closing:

1. There is a rapid change in thinking toward capt re of storm ater & Greencapture of stormwater & Green Infrastructure

l i i2. Regulations are written3. Should blanket regulations be used for

“simplicity” or is there a simple way to attain simplicity at less “technical cost?”

“continuous simulation is now non“continuous simulation is now non--optionaloptionalcontinuous simulation is now noncontinuous simulation is now non--optional optional BUT you can get its power without everyone doing it for every site.”BUT you can get its power without everyone doing it for every site.”

Actually right now Nashville couldActually right now Nashville couldActually right now Nashville could Actually right now Nashville could care less about Green Infrastructurecare less about Green Infrastructure