BUI Final Presentation

8/10/2019 BUI Final Presentation

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Outlines

1. Introduction

2. Literature Review

3. Factors affecting BMP Selection

4. Common BMPs used in Green Buildings

5. Data & Procedure for Planning Stormwater Design

6. Case Project Studies

7. Difficulties & Solutions

8. Conclusions

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Research Process

1. Review literature

2. Analyze factors

affecting BMP selection

3. Survey studies to define

common BMPs used in

green buildings

4. Find data and equations

for LEED & Greenroads

5. Compare LEED &

Greenroads in

stormwater design

6. Establish aprocedure for

planning in

stormwater

design

7. Use two casestudies to

examine the

established

procedure

8. Propose difficulties and

solutions for

stormwater design

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2.1 Best Management Practices (BMPs)

Structural BMPs refer to physical

structures designed to remove

pollutants from stormwater runoff,

reduce downstream erosion,

provide flood control, and

promote groundwater recharge.

They typically require engineering

design.

Non-structural BMPs include a

range of pollution prevention,

education, management and

development practices designed to

limit the conversion of rainfall into

runoff.

They normally do not have

technical or engineering designs

BMPs

Structural BMPs Non-structural BMPs


2.1 Best Management Practices (BMPs)

1. Dry extended-detention pond2. Wet ponds

3. Infiltration basins

4. Infiltration trenchs

5. Permeable pavements

6. Bioretention

7. Sand & organic media filters

8. Constructed wetlands

9. Grassed swales10. Vegetated filter strips

11. Catch basins/Catch basins inserts

12. Rain barrels and cisterns

13. Manufactured products for stormwater inlet

14. Greenroofs

15. Rain gardens

16. Dry wells

17. Alum injection18. Buffer zones

19. Open space design

20. Urban forestry

21. Conservation easements

22. Infrastructure planning

23. Narrower residential streets

24. Curb cuts

25. Green parking26. Alternative turnarounds

27. Alternative pavers

28. BMP inspection & maintenance

29. Ordinances for post-construction runoff

30. Zoning

31. Modular treatment system

32. Dynamic vortex separators

BMPs

Structural BMPs Non-structural BMPs

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Stormwater

Wetlands

Bioretention

Greenroof

Permeable

Pavement

Grassed swale

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2.2 Low Impact Development (LID)

LID is developed from BMPs. This is a stormwater management strategy

and emphasizes on design to mimic the natural hydrology for the site

LID

Practices

Designstrategy

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2.3 Stormwater Design Credits in LEED

26 pts

10 pts

35 pts

14 pts 15 pts

6 pts 4 pts

SS WE EA MR IEQ ID RP

Allocation of points in 7 categories of LEED

Objectives1. SS 6.1- Stormwater design: Quantity control

(1 point)

2. SS 6.2- Stormwater design: Quality control

(1 point)

StormwaterDesign

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EW - 2 Runoff flow control

ROW

The goal of this credit is to mimic predevelopment hydrological conditions in

the right of way (ROW) and minimize offsite stormwater control.

EW - 3 Runoff quality

The goal of this credit is to improve water quality (80% volume treated with 3

treatment levels) of stormwater runoff leaving the roadway ROW.

2.5 Stormwater Design Credits in Greenroads

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3. Factors affecting BMP selection

3.1 Sources to define factors

America Europe Australia

East Asia

DID, MAS

3.1 Factors for BMP selection

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No.


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4. Common BMPs usedin Green Buildings

1. USEPA 2. LEEDprojects

1. USEPA

BMPs Used (%)

1. Grassed swales 62

2. Bioretention (including rain garden) 52

3. Permeable pavement 47

4. Rain barrels and cisterns 45

5. Curb cuts 38

6. Greenroofs 17

- 32BMPs (including structural and non-structural BMPs) were proposed in 2003.

- 6common BMPs used according to a report of ASLA in 2011.

479case

studies

from

43states

6

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2. LEED projects

LEED version

Projectv2.0 v2.1 v2.2 v3 Total

Available 289 1,202 3,038 0 4,529

With case study only 65 47 15 0 127

Number of reviewed LEED projects

11 projects are removed due to missing information. 116

%

30 %

41 %

51 %

96 %

0

10

20

30

40

50

60

70

80

90

100

Certified Silver Gold Platinum

Percentage of projects earning

SS 6.1 & SS 6.2

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Common BMPs used in Green Buildings

1

2

2

3

514

14

16

19

2034

38

42

42

76

15. Infiltration trench

14. Restored Riparian buffer

13. Catch basin

12. Infiltration basin

11. Open space design

10. Constructed Wetland

9. Sand/Vegetated filter

8. Wet Pond

7. Extended Detention pond

6. Curb cuts

5. Greenroof

4. Rain Barrel & Cistern

3. Bioretention/Rain garden

2. Bio/Grassed Swales

1. Permeable Pavement

BMPs LEED Projects

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5.1 Equations and Data needs for LEED

1. Runoff coefficients for different surface types and for the site.

[C] = (Ci Ai) Ai

2. Runoff volume is often calculated by the NRCS method (1986).

Runoff volume[] = 0.2

+ 0.8

The value of Sis related to the soil and surface characteristics of the drainage

area by the following equation:

=1000

10

CNis the curve number, unitless. It has a range from 30 to 100. The low number

indicates the area has low runoff potential while large number means high

runoff potential.


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3. Peak flow rate for the site.Peak Flow Rate[Q]= C I A

Website provides rainfall data: www.cwb.gov.tw (Taiwan)

www.nws.noaa.gov (U.S.)
http://www.nws.noaa.gov/http://www.cwb.gov.tw/http://www.nws.noaa.gov/http://www.nws.noaa.gov/http://www.cwb.gov.tw/


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5.1 Equations and Data needs for LEED

Climate zone Annual Precipitation (in) Estimated 90% of annual rainfall (in)

Humid >40 1 over total site

Semiarid 20-40 0.75 over total site

Arid


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5.2 Comparisons between LEED & Greenroads

SimilaritiesDifferences

Requirements, Equations and Data needs

LEED requirements and equations are simpler than Greenroads in both credits

(stormwater quantity and quality). Especially in stormwater quality credit, Greenroadsis more complicated with three treatment levels (basic, enhanced & oil)

Advantages

LEED has a large database with many certified projects because it was developed for a

longer time, there are more examples to follow to obtain LEED certification.

Greenroads needs time to accumulate certified projects to form a stronger database.

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5.3 Establish Procedure

1. Collect

data

2. Select

suitableBMPs

3. Develop

SWMconcept plan

4. Evaluate

performance

ImplementSWM plan

Execution

Planning

Procedure for planning stormwater design

Modify concept

planNO

YES

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Step 1 Collect data


o Guidelines of stormwater management from governments or regulations,

such as manuals of BMPs.

o Location, climate zone of the project, such as being located in the humid,

arid or semiarid place.

o Square area including total area and imperviousness area, total segment

length and total width of cross section.

o Surface type on site, runoff coefficients for surface types.

o Drainage area characteristics and the curve number.

o Precipitation/weather data, including rainfall depth, storm duration in 1-

year, 2-year 24-hour, rainfall per 24 hours, and 90% of annual rainfall.


Step 2 Select suitable BMPs


Site suitabilityparameter

Cost &

community concern

BMP selection process

List of commonBMPs

Phase 1 Phase 2Input

List of the best

BMPs for a project

Output

BMP selection process

Site Suitability Cost & Community concern

1. Land use

2. Space required

3. Size of drainage are4. Drained soil and Steep slope

5. Quantity control

6. Water quality

7. High % impervious area

1. Construction cost

2. Maintenance cost

3. Community acceptance4. Conservation habitat

5. Safety concern

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Step 3 Develop SWM concept plan

Items should be included in a concept plan

o Land use planning, by indicating positions of building, landscape area, road.

o All the suitable BMPs attained and their location.

o Directions of runoff flow from each practice and linkage to sewer system.

Step 4 Evaluate performance of selected BMPs

This step uses equations and dataproposed to assess whether a project is

able to earn credits in the LEED or not.

o

If the project can meet credit requirements, it will move to implement theSWM plan.

o If not, the project team has to define what the problems are, what is not

reasonable in design and which parameters should be considered by going

back to step 3 to modify the concept design.

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1. Bioretention

2. Grassed swales

3. Permeable

pavement4. Curb cuts

Selected BMPS

Baseline case

Design case

Quantity volume reduction of the renovation office

Quality control in the renovation office

TSS = 60 + 85(60 x 85)/100 = 94% removal (> 80%)

WQVH= (0.083 ft) A = 0.083 ft 3.5 acres = 0.29arce-ft

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Case 2 Fisher Pavilion at Seattle Center, WA, U.S.

This building was rebuilt in November 2002, and got certified by LEED

v2/v2.1 with 29 points in total, but did not achieve stormwater credits of

LEED. It provides 52% of pervious area.

The site includes an exhibition hall, upper plaza, lower plaza, and civic green.

Project location

Section

S= 2.6 acres

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1. Grassed swales

2. Bioretention

3. Permeable

pavement

Selected BMPS

Baseline case

Design case

SWM concept plan

Quantity volume and peak flow rate reduction of Fisher Pavilion

Quality control in Fisher Pavilion

TSS = 60 + 85(60 x 85)/100 = 94% removal (> 80%)

WQVS= (0.063 ft) x 2.6 acres = 0.16acre-ft

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7. Difficulties & Solutions

7.1 Difficulties encountered in implementation7.2 Solutions

1. Solutions to low data availability

The government should take the lead role to launch the

research about stormwater management in many locations.

This work will help define and collect data which relate to

weather, rainfall event, conditions and characteristics.

2. Solutions to lack of knowledge in design

Education is the best solution to improve awareness of

project participants in stormwater management. Land use

planning, technical capacities of BMPs or LID design, etc.

should be educated.

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8. Conclusions

8.1 Achievements

1. The research defines twelve factors affecting BMP selection and ten BMPs

commonly usedin green buildings based on guidelines and LEEDs projects.

2. This research presents how to achieve effective stormwater design throughthe use of figures, tables, equations, data, and regulations which contain

necessary information and stormwater design parameters for the site.

3. The established procedure helps designers have a better understanding of

how to design a good SWM plan.

4. Two main difficultiesin low data availability and lack of knowledge in

design with proposed solution will help the procedure better in the future.

8.2 Limitations

1. Non-structural BMPs are not mentioned deeply in the research because

they are related to principles and require sufficient understanding from

communities and designers before implementation.

2. Limited data availability, so only some projects in the U.S. are discussed

3. Limited knowledge, only existing equations and regulations from LEED

and Greenroads are explained, but the background knowledge of these

equations and regulations is not discussed.

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Thank you for your attention !

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BUI Final Presentation

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