1. Siting, and Cost Effectiveness Analysis
City-Wide Green Stormwater Infrastructure Sizing,
Siting, and Cost Effectiveness Analysis
Mike Blackhurst, PhD, PE (TX) Research Scientist Heinz Endowments University of Pittsburgh
28-FEB-17

2. I -, ---,, wall _ Cnapel BaroJ i-ima Tcrw1;3* aciraugh
a• • ..—.7711•411V _
Cnapel BaroJ
i-ima Tcrw1;3*
"YSS'49";
aciraugh
wall
lillefirrO ID::16141
'arr ' I
Pcnn Hills T. waship
Rain gardens k . IN ,
RNN GARDENS D,,, ilk . r
.__
__ . 1
dlo 1.1 i - IM-.,',
r' ,alitiou
-, ---,,
)..._ f
+ VilllicirlSbUfg Oprough .r._ j r • I
1 .., Chiptriiii 5
.g•L-i,

3. Hydrologic and hydraulic modeling
Integrating sewershed and GI modeling contexts involved interdisciplinarity.
Hydrologic and hydraulic modeling
Sizing and Engineering
+ siting + economic +
analysis analysis
Policy analysis
Achieved by Green Infrastructure
Overflow Reductions
Implementation opportunity
Current Deployments
Technically Realistic Cost
Feasible Potential Optimal
Policy Enabled
Context for our project

4. Gray and green model results can be integrated using total cost curves.
1. Cost of compliance with gray when green = 0 ($3B-$5B)
Total minimum cost*
TOTAL COST
INFLOWS REDUCED
2. Cost of compliance less than total minimum technology cost. Significant cost efficiencies realized by green infrastructure.
3. Cost of compliance exceeds total minimum technology. Moderate cost efficiencies realized by green infrastructure.
4. Compliance met with all gray solution because cost of gray + green exceeds cost of gray when green = 0

5. Our approach is
Estimate the cost and inflow performance of select GI for each parcel in Pittsburgh, PA
Prepare marginal and total cost curves for GI
Develop extensible methods to accommodate future changes
Publish the results in an open and extensible format
Network results and future work with others

6. A summary of methods
(1) Characterize land use by parcel using best available data
(2) Apply sizing and siting criteria to identify all feasible installations of
Rain gardens
Downspout disconnects
Green roofs
Pervious pavement
(3) Run hydrologic models for each feasible installations
(4) Estimate cost effectiveness of each installation
(5) (Publish results and hope for more!)

7. Step 1. Land use. Harmonize land use layers.

8. Step 1. Land use. Harmonize land use layers.

9. Step 2. Divide surface by parcel and building buffer.

10. Step 3. Land use. Associated proximity to right-of-way

11. Step 4. Attribute each subdivided land with topographical information.

12. See example retrofits on project website

13. Process Flow Preparation of Geospatial Data (ArcMAP) Not
currently extensible
Land use shapefile
Apply sizing and siting criteria to Identify GI locations
Tabular data for SWMM
Preparation and simulation of SWMM
(Python + SWMM)
Extensible, run-time 30 days
Table of SWMM hydrologic results
Cost estimation
Publish to map
(R)
Extensible, run-time 1 hr
Extensible, run-time hrs

14. Mil gal overflows reduced
Summary statistics of results
Collection Area
ALCOSAN
Priority Sewersheds
Mil gal inflow reduced
Mil gal overflows reduced
million sq
for 2003 precop
Net Present Value ($M)
for 2003 precip
CE in $ / gal Overflow GI ft
count
mean (range)
mean (min + 2 sd)
Disconnect
11.6
11,600
35 ( )
3.5 ( )
6 (3-12)
0.9 ( )
0.2 ( )
Building to rain garden
14.9
22,200
100 ( )
113 ( )
32 ( )
44 ( )
1 ( )
Surface to rain garden
18.5
23,100
65 ( )
130 ( )
20 (11-33)
54 (31-86)
2.5 (0.1 -5)
Permeable pavement
96.8
12,100
920 ( )
1,100 ( ,280)
220 ( )
350 ( )
1.6 ( )
Green roof
13.3
3,100
61 (55-80)
2,110 (1, ,930)
10 (8 - 12)
410 ( )
35 ( )
totals
215
139,000
1,200 ( ,500)
3500 (2, ,600)
290 ( )
860 ( ,150) -
An overall 5.5% (4%-1%) reduction in inflows for year 2003 design storm

15. Exemplary Product: Marginal GI Cost Curves

16. Published in an open, extensible manner
Explore resources on project website.

17. Gray and green model results can be integrated using total cost curves.
1. Cost of compliance with gray when green = 0
Total minimum cost*
TOTAL COST
INFLOWS REDUCED
2. Cost of compliance less than total minimum technology cost. Significant cost efficiencies realized by green infrastructure.
3. Cost of compliance exceeds total minimum technology. Moderate cost efficiencies realized by green infrastructure.
4. Compliance met with all gray solution because cost of gray + green exceeds cost of gray when green = 0

18. Acknowledgements Sponsored by
Mascaro Center for Sustainable Innovation at University of Pittsburgh
Heinz Endowments