Green Infrastructure Implementation Planning for Multiple ...
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Imagine the result Hazem Gheith , ARCADIS September 10, 2014 Green Infrastructure Implementation – Planning for Multiple Objectives
Transcript of Green Infrastructure Implementation Planning for Multiple ...
Imagine the result
Hazem Gheith , ARCADIS
September 10, 2014
Green Infrastructure Implementation – Planning for Multiple Objectives
Integrated Plan for Stormwater Control
• Integrated Plan Objective
• Sanitary Modeling and Overflow Mitigation
Plan
• Stormwater Modeling and Flooding Mitigation
Plan
Integrated Plan Objective
Protect Public Health
• Sanitary System:
• Mitigate sewage overflowing to receiving waters or backing
up into basements by reducing excessive rain driven inflow
and infiltration (RDII)
• Stormwater System:
• Reduce pollution to the receiving waters and mitigate
backups and street flooding
• Control cost by coordinating one solution to both
Workflow Diagram
Mitigate SSOs,
CSOs and WIB
Additional Flow
between the
Systems
Construct House
Level Resolution
Storm Model
Investigate Runoff
and Pollutant
Loading (GIS)
Quantify Inflow
Sources and
Deficiencies
Mitigate Pollution
(TMDL) and Street
Flooding
Define Suite of
Effective GI
Technologies
Construct House-
Level Resolution
H/H Model
Investigate RDII
Sources
(GIS)
Define Suite of
Effective RDII
Reductions Plans
Sanitary Mitigation Planning Stormwater Mitigation Planning
Understand
Existing LOS
Quantify Inflow
Sources and
Deficiencies
Alternatives
Planning
One Integrated
Plan Solution
Cost Benefit Analysis
Balance RDII
Reduction and
Storm Water
Controls to Make
Certain One
System is not
Improved at the
Expense of the
Other!
Define and
Understand the
Problem
Prepare the
Planning Tool
Blueprint Columbus
City wide Integrated Plan to be
presented to OEPA by September
2015
• Pilot project – Park of Roses
Sub-basin:
• Mitigate an active SSO at
the Park
• Reduce stormwater street
flooding
• Improve TMDL into the
Ravine
POR
sub-basin
• Sanitary Overflow Mitigation Plan
• Detailed Sanitary Modeling
• Quantify RDII sources
• Select mitigation plan
RDII Process and Potential Solutions
Leaks through
sanitary system
defects as RDII
Precipitation
Evapotranspiration
Surface runoff
Routing through
Storm System
Storm water
arrives at vicinity
of sanitary system
Receiving waters
Infiltration to
Groundwater
Mitigation 1:
Divert runoff
away from
sanitary system
Mitigation 2:
Rehab pipes and
MHs defects in
sanitary system
Increase flow
into storm
system
Increase flow
into storm
system
Potential RDII Inflow Points
(1) Direct Downspout Connection
(2) Foundation Drain
(3) & (4) Private and Public Lateral
Service
(5) & (6) Manhole Lids and
Manholes Castings
(7) & (8) Manhole Structures and
Sewer Mains under pervious or
cracked impervious surface
(9) Sewer Mains in trenches parallel
to colocated storm pipe trenches
1
2 3
4
5 6
7
8 9
(1) Direct Downspout Connection
• Contributing area = roof top
• Remediation: Redirect roof
drainage to the street
1
2 3
4
5 6
7
8 9
(2) Foundation Drains
• Contributing area = roof top + buffer
area around the house
• Remediation: Redirect roof drainage
to the street (partial) or install
stormwater sump pump
1
2 3
4
5 6
7
8 9
(3) & (4) Private and Public Laterals
• Contributing area = buffer
area around the lateral pipe
• Remediation: Line the lateral
pipes
1
2 3
4
5 6
7
8 9
(5) & (6) Manhole Lids and Castings
• Contributing area = ponding
around and above the MH
• Remediation: Rehab MHs cover
and casting
1
2 3
4
5 6
7
8 9
(7) & (8) MH Structure and Sewer Main
• Contributing area is a buffer
around the main pipe
• Remediation: Line the main pipe
and rehab the MHs structure
1
2 3
4
5 6
7
8 9
(9) Sewers Colocated with Storm pipes
• Contributing leaks from
pressured storm pipes to
sanitary pipe trenches
• Remediation: Line sanitary
and/or storm pipes 1
2 3
4
5 6
7
8 9
Roof
Drainage
Splashing
Roof
Drainage
Directly
Connected
Roof
Drainage
To Street
Street/
Driveway
Buffer1
(Splash
houses)
Buffer2
(Rest of
houses)
Lawn
Area Garages
Main
Sewers
Area
Lateral
Pipes
Area
Storm Inlet Sanitary System
Subareas and Connectivity
Split the area into its RDII sources (GIS)
Upstream
Strom
System
Colocated
Main
Trench
Impervious surface
Areas with aquifers
Surface flow
Subsurface flow
Computed RDII Sources Percentage
Sources A22A A26A 0163 0226 0257 0283
Foundation Drain Private 34.4% 36.3% 31.9% 34.5% 30.5% 43.6%
Private Lateral Private 25.8% 18.2% 22.3% 22.7% 15.1% 15.7% Co-located Mainline/Storm
Pipes Public
26.9% 13.3% 26.4% 16.8% 20.4% 16.2% Mainline and Manhole
Structures Public
10.1% 16% 17.6% 33.2% 29.1% 22.4%
RDII Mitigation Plan “Blueprint Columbus”
House
Splashing
House
Directly
Connected
House
To Street
Remaining
Impervious
Area
Buffer1
Buffer2
Remaining
Pervious
Area Garages
Main
Sewers
Area
Lateral
Pipes
Area
Storm System Sanitary System
Quantifying RDII Mitigation
Sump Pump Lining
Redirection
Redirection
Evaluate and mitigate
negative impact on the
storm system
Upstream
Strom
System
Colocated
Main
Trench
Lining
• Stormwater Flooding Mitigation Plan
• Detailed runoff modeling
• GI footprint to mitigate roofs rerouting
• GI footprint to improve water quality
• Additional plans to increase stormwater LOS
Stormwater Planning Objectives
Objective 1:
Mitigate the impact of RDII reduction on the stormwater flow using
green infrastructures.
Objective 2:
Using GI, how much water quality improvement could be achieved?
Objective 3:
How much stormwater LOS could be achieved by adding more GI
footprints and/or gray structures (upsized pipes)?
Objective 1: Mitigate the impact of
RDII reduction on the stormwater
Evaluation Process:
• Calculate stormwater LOS before and after RDII
mitigation
• 16 years of spatially-distributed historical storm data
• Calculate required GI footprint to mitigate the impact
• Calculate GI construction cost
Pilot Area: Chatham Rd
Existing Flooding LOS is ~1.6 years
Detailed Modeling
Area: 30 acres
15 storm inlet sub-catchments with average slope 2.6%
!."
!.!.
!.!.
!.!.
!.!.
"
"
""
""
"
""
"
"
"
!.
"
" ACTON RD
BLENHEIM RD
RICHARDS RD
CHATHAM RD
NORTHRIDGE RD
N H
IGH
ST
FO
ST
ER
ST
SH
AR
ON
AV
GRANDEN R
D
CHATHAM RD
Model Enhancements
• A house-scale model is needed to prepare for an educated GI
alternative analysis
Lawns
Driveways
/ Streets
House
Roofs
(discon.)
Storm Pipe
Storm
Inlet
House
Roofs
(to street)
Commerc
ial Roof Parking
Outfall
Alleys
House Perimeter
Split
Garages
Detailed Runoff Model
• Split inlet catchments into
detailed surface features
Garages – 1.5 acres
Roofs draining to Lawn
Roofs draining to Street
Lawn area around the house (high
infiltration rate below top soil)
Lawn area away from the house (low
infiltration rate below top soil)
Streets – 6.3 acres
House Perimeter
Driveway
/ Streets
Splash
Roofs
Strom Pipe
Storm
Inlet
Roofs
to Street
Roofs to
Sanitary
Outfall
Lawns Garages
to Lawn
3.9
acres
17.6
acres
Sanitary
Pipe
Existing Condition
• No roofs directly connect to
sanitary pipes
House Perimeter
Driveway
/ Streets
Roofs to
Lawn
Storm Pipe
Storm
Inlet
Roofs
to Street
Roofs to
Sanitary
Outfall
Lawns Garages
to Lawn
• 50% of roof drainage splashes around the house
• Route all roof drainage to street (to minimizing RDII in
sanitary system)
Base Scenarios
Buffer
Lawns
Driveway
/ Streets
Roofs to
Lawn
Manhole
Storm
Inlet
Roofs
to Street
Roofs to
Sanitary
Outfall
Lawns Garages
to Lawn
Existing versus Base Conditions Flood
Recurrence
• Track flooded volume
from all manholes in
pilot area
• Existing LOS: ~1.6 yrs
• Base condition LOS:
~1.2 yrs
Event
Rank
Recurrence
(Years)
Existing Base
Date OF Vol.
(MG) Date
OF Vol.
(MG)
1 27.0 6/26/08 0.31 6/26/08 0.40
2 10.1 8/4/03 0.24 8/4/03 0.28
3 6.2 7/27/97 0.23 7/27/97 0.27
4 4.5 5/19/05 0.15 8/30/03 0.24
5 3.5 6/29/98 0.12 6/29/98 0.20
6 2.9 8/30/03 0.08 5/19/05 0.17
7 2.5 7/11/11 0.06 5/28/02 0.09
8 2.1 5/28/02 0.05 7/11/11 0.09
9 1.9 9/23/00 0.04 7/18/96 0.06
10 1.7 7/24/11 0.02 9/23/00 0.06
11 1.5 7/22/04 0.03
12 1.4 7/22/06 0.03
13 1.3 7/24/11 0.02
14 1.2
15 1.1
16 1.0
Existing versus Base Conditions
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0 5 10 15 20 25 30
Tota
l MH
Ove
rflo
w V
olu
me
(M
G)
Recurrence (years)
MH Flooding Recurrence Curve
Existing
Base
• Calculate rain gardens footprint required to bring
system back to existing condition
• Apply rain gardens footprint
Mitigation Scenarios
Buffer
Lawns
Driveway
/ Streets
Roofs to
Lawn
Storm Pipe
Storm
Inlet
Roofs
to Street
Outfall
Lawns Garages
to Lawn
Rain
Garden
Assume rain gardens with 4 feet depth (3 feet of storage material with 33%
available voids plus 1 ft of freeboard)
Assume installation and O&M cost of $70 per SF
Rain Gardens Footprint Required to Offset
Additional Flooding from Rerouting Roof
Drainage to Street
LOS
(years)
Existing
Flooding
Volume (MG)
Additional
Flooding
Volume
(MG)
Required
Rain Garden
Footprint
(SF)
Cost per
acre
10 0.24 0.08 5,164 $12,369
5 0.15 0.06 3,725 $8,922
2 0.05 0.04 2,232 $5,346
1 0 0 0 $0
Chatham Rd: Existing vs. Base Conditions
Objective 2: How much water quality
improvement could be achieved?
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
90.0%
100.0%
$- $200,000 $400,000 $600,000 $800,000 $1,000,000 $1,200,000
To
tal S
usp
en
ded
So
lid
s R
em
ova
l %
Cost/10Acres
Performance Curve for Rain gardens TSS Removal vs. Cost per 10 Acres
Medium Density Residential, 0.01 Soil Infiltration Rate, 80% Runoff Capture into the RG
Knee of the curve is at about
58% TSS removal
(~$15,000/acre)
* Prepared by EMH&T for the City of Columbus
Base versus WQ RGs
Ran
k
Recurrence
(Years)
Base Condition
Date OF
(MG)
1 27.0 6/26/08 0.40
2 10.1 8/4/03 0.28
3 6.2 7/27/97 0.27
4 4.5 8/30/03 0.24
5 3.5 6/29/98 0.20
6 2.9 5/19/05 0.17
7 2.5 5/28/02 0.09
8 2.1 7/11/11 0.09
9 1.9 7/18/96 0.06
10 1.7 9/23/00 0.06
11 1.5 7/22/04 0.03
12 1.4 7/22/06 0.03
13 1.3 7/24/11 0.02
14 1.2
15 1.1
16 1.0
Ran
k
Recurrence
(Years)
WQ Rain Gardens
Date OF
(MG)
1 27.0 6/26/08 0.35
2 10.1 7/27/97 0.26
3 6.2 8/4/03 0.18
4 4.5 6/29/98 0.17
5 3.5 5/19/05 0.16
6 2.9 8/30/03 0.09
7 2.5 7/11/11 0.01
8 2.1
9 1.9
10 1.7
11 1.5
12 1.4
13 1.3
14 1.2
15 1.1
16 1.0
• WQ RGs increases LOS from 1.2 years to 2.4 years
• 11,700 sf of water quality rain gardens for the 30 acres
Objective 3: Increase LOS by adding
More GI per Site Availability
ACTON RD
BLENHEIM RD
RICHARDS RD
CHATHAM RD
NORTHRIDGE RD
N H
IGH
ST
FO
ST
ER
ST
SH
AR
ON
AV
FALLIS RD
GRANDEN
RD
AMAZON PL
CHATHAM RD
ACTON RD
FO
ST
ER
ST
Three Scenarios:
• Max RG on tree lawn
• Max RG on tree lawn and street
• Max RG and pervious pavement
at intersections (18” gravel)
LOS versus Cost Comparison
0
0.5
1
1.5
2
2.5
3
3.5
$0 $20,000 $40,000 $60,000 $80,000 $100,000 $120,000
LO
S, Y
ea
rs
Construction Cost (per acre)
Existing
Base
RG WQ
Max RG
Tree Lawn
Max RG
Tree Lawn +
Bump Out
RG + PP
Flow LOS (yrs) versus Construction Cost (per acre)
Gray Improvement Level 1
Pipe Size
Required for
LOS (ft)
WQ RG
Condition
(LOS 2.1
Years)
Level 1 Gray
(LOS 4.5 years)
Pipe 1 18” 24”
Pipe 2 18” 21”
Pipe 3 18” 21”
Pipe 4 18” 21”
Pipe 1 2 3 4
Rank Recurrence
(Years)
WQ Rain Gardens Gray Level 1
Date MH OF Vol
(MG) Date
MH OF
(MG)
1 27.0 6/26/08 0.35 5/19/05 0.05
2 10.1 7/27/97 0.26 7/27/97 0.03
3 6.2 8/4/03 0.18 6/26/08 0.02
4 4.5 6/29/98 0.17
5 3.5 5/19/05 0.16
6 2.9 8/30/03 0.09
7 2.5 7/11/11 0.01
8 2.1
9 1.9
10 1.7
11 1.5
12 1.4
13 1.3
14 1.2
• Start with WQ rain
gardens footprint, upsize
deficient pipes to reach a
5 years LOS
Gray Improvement Level 2
Pipe Size
Required
for LOS (ft)
WQ RG
Condition
(LOS 2.1
Years)
Level 2 Gray
Pipe 1 18” 24”
Pipe 2 18” 24”
Pipe 3 18” 21”
Pipe 4 18” 21”
Pipe 5 12” 21”
Pipe 1 2 3 4
Rank Recurrence
(Years)
WQ Rain Gardens Gray Level 2
Date OF (MG) Date OF
(MG)
1 27.0 6/26/08 0.35 7/27/97 0.03
2 10.1 7/27/97 0.26 5/19/05 0.03
3 6.2 8/4/03 0.18
4 4.5 6/29/98 0.17
5 3.5 5/19/05 0.16
6 2.9 8/30/03 0.09
7 2.5 7/11/11 0.01
8 2.1
9 1.9
10 1.7
11 1.5
12 1.4
13 1.3
14 1.2
5
• Upsize deficient pipes to
reach a 10 years LOS
LOS versus Cost Comparison with Gray
Flow LOS (yrs) versus Construction Cost (per ac)
0
1
2
3
4
5
6
7
$0 $20,000 $40,000 $60,000 $80,000 $100,000 $120,000
LO
S, Y
ea
rs
Construction Cost (per acre)
Existing
Base
RGWQ RGTL
RGTL+BO RG & PP
Green Only
Level 1 gray
Level 2 gray
Pilot Area 2: Weisheimer Rd
MH Flooding LOS: ~5 months
Chatham vs. Weisheimer
Flow LOS (yrs) versus Construction Cost (per ac)
0
0.5
1
1.5
2
2.5
3
3.5
$0 $20,000 $40,000 $60,000 $80,000 $100,000 $120,000 $140,000 $160,000
LO
S, Y
ea
rs
Construction Cost (per acre)
Chatham
Weisheimer
Existing
Base
RG WQ
RG TL
RG TL + BO
RG + PP
Existing
Base
RG WQ
RG TL RG TL + BO
RG + PP
0
1
2
3
4
5
6
7
$0 $20,000 $40,000 $60,000 $80,000 $100,000 $120,000 $140,000 $160,000
LO
S, Y
ea
rs
Existing Base RGWQ
RGTL
RGTL + BO RG & PP
Weisheimer Rd (cost per acre )
0
1
2
3
4
5
6
7
$0 $20,000 $40,000 $60,000 $80,000 $100,000 $120,000
LO
S, Y
ea
rs
Chatham Rd (cost per acre )
Existing Base RGWQ RGTL
RGTL+
BO RG & PP
Conclusions
• RDII:
• Detailed modeling approach for RDII sources allowed for an
educated understanding and quantifying RDII flows.
• This in turn allowed for a more effective RDII reduction plan.
• Stormwater:
• Detailed modeling approach allowed for an improved
quantification of additional runoff due to reduction in RDII.
• It also improved evaluating the GI units to increase stormwater
flooding protection level.
• Coordinating between both systems allowed for one integrated plan to:
• Reduce RDII,
• Improve water quality,
• Reduce flooding.
