charleston presentation final

Austin Balser, Daniel Chewning,

Kelly Creswell, Tyler DuBose

Problem Recognition:

Urban and suburban developments lead to high runoff rates and low infiltration rates which reduce the quality of ground and surface water

Definition:

Construction of Sea Aire residential community will create an increase in impervious surface leading to the potential of increased stormwater runoff

http://www.modelstoglobe.com/ESW/Images/Earth_Globe.png

Goal Design a stormwater management plan for Sea Aire

subdivision that: Meets state and local regulations by ensuring the peak

flow during a 2 and 25 year storm event doesn’t exceed pre-development levels 2 year storm: 2.31 cfs

25 year storm: 7.07 cfs

Ensures the post-development runoff volume doesn’t exceed pre-development levels 2 year storm: 29,555 ft3

25 year storm: 47,353 ft3

Robinson Design Engineers: Site Plan

Constraints & Considerations Ecological: Must work with existing soil, water table,

vegetation, and waterways. Existing wildlife and plant species must also be considered.

Sustainability: Consider long term ecological and social impacts

Ultimate use: Residential living and recreational space.

Safety: Consider pets and small children that could enter LID areas.

Skills: Software modeling

Cost: Budget of $1200 for design process. Must account for travel expenses, software, and testing services

Questions of User, Client and Designer User- Residents of Sea Aire

What is a rain garden?

Why are there plants in the ditch?

What do I have to do?

Client- New Leaf Builders through Robinson Design Engineers Will this meet regulations?

Will it cost more?

Effectiveness compared to conventional?

Designer- The design team and RDE Will this be long lived?

Can this be an amenity?

How are state regulations met?

Literature Review Governing Equations

Conventional and LID comparison

Data Collection

Governing Equations Energy Balance

Mass Balance

Curve Number Method

Manning’s Equation

Stormwater Management Methods Conventional Methods versus LID methods

Conventional methods provide solutions at the bottom of the site (ponds, basins, ect.)

Low impact development methods encourage infiltration from all locations on site in an effort to mimic the more natural process

Conventional vs. LID Conventional

Detention basins

Drains

Concrete ditches

Culverts

http://precisionsetup.com/wp-content/uploads/2013/03/v-ditch-4.jpg

LID

Green roofs

Rain water collection

Constructed wetlands

Bioretention/rain garden

Permeable pavement

http://www.ecy.wa.gov/programs/wq/stormwater/municipal/LID/TRAINING/LIDswale.jpg

Conventional vs. LID Cost and Efficiency

Case Study: Sommerset Community in Prince George’s County, MD

Residential subdivision constructed half with LID methods and half with conventional methods

LID methods: rain gardens and bioretention

Saved $4,000 per lot using LID methods

20% less runoff volume using LID

http://search.proquest.com.libproxy.clemson.edu/docview/897143027?pq-origsite=summon

Data Collection: Lab and Field Testing Sieve Test

Soil particle size and classification

Infiltrometer Test

Infiltration rate of soil on site

Sieve Test Placed soil sample in oven for 48 hours to dry

Sifted soil through sieves

Weighed the soil collected on each sieve

Analyzed data to determine soil composition

http://www.aimsizer.com/sieves-screeners-separators-images-and-pictures/aimsizer-test-sieves.gif

Sieve Test Results Sieve #

Opening Size (mm)

Mass (w/ tin) (g)

Mass of soil retained (g)

% of soil retained Classification of soil

retained

6 3.35 2.395 0.307 0.553 Sand

10 2 2.318 0.231 0.415 Sand

18 1 2.602 0.515 0.927 Sand

230 0.0635 53.525 51.438 92.630 Sand

270 0.05334 4.493 2.405 4.332 Silt

325 0.04318 2.538 0.450 0.811 Silt

less than 0.04 2.272 0.185 0.333 Silt

Particle Diameter range (mm) Classification 2

Sand 0.0625

0.06249 Silt

0.001953125 0.001949318

Clay 0.00012207

Total % Sand 94.52

Total % Silt 5.48

Void Space = 0.9452 * 0.43 + 0.0548*0.45 = 0.43

Infiltrometer Test

http://www.nzdl.org/gsdlmod?e=d-00000-00---off-0hdl--00-0----0-10-0---0---0direct-10---4-------0-1l--11-en-50---20-about---00-0-1-00-0-0-11-1-0utfZz-8-00&a=d&cl=CL1.8&d=HASH3b4d99e5f9716ab628b9b2.8.3

Infiltrometer Test Results Infiltration rate = 3 in/hr

Time (min) Water Level (in) New Water level after Water

Added (in) Infiltration Rate

(in/hr)

0 1.6

4.25 1.35 1.65 3.53

7 1.5 3.27

15 1.23 1.87 2.03

20 1.6 3.24

25 1.35 1.85 3.00

30 1.55 3.60

35 1.36 1.83 2.28

40 1.52 3.72

45 1.35 1.8 2.04

50 1.51 3.48

55 1.21 3.60

60 0.98 2.76

Average 3.05

Analysis of Information Rainfall Distribution Data: Type II

2-year storm: 4.3 inches

25- year storm: 8.0 inches

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 5 10 15 20 25 30

Cu

mm

ula

tiv

e R

ain

fall

(in

)

Time (hours)

Time

(hr)

Fraction of 24

hour rainfall

Rainfall

(in)

0 0 0

2 0.02 0.086

4 0.043 0.1849

6 0.072 0.3096

7 0.089 0.3827

8 0.115 0.4945

8.5 0.13 0.559

9 0.148 0.6364

9.5 0.167 0.7181

9.75 0.178 0.7654

10 0.189 0.8127

10.5 0.216 0.9288

11 0.25 1.075

11.5 0.298 1.2814

11.75 0.339 1.4577

12 0.5 2.15

12.5 0.702 3.0186

13 0.751 3.2293

13.5 0.785 3.3755

14 0.811 3.4873

16 0.886 3.8098

18 0.93 3.999

19 0.945 4.0635

20 0.957 4.1151

24 1 4.3

Two Year Storm

Determining Site Runoff Determined weighted curve number for site using

WebSoil Survey Data

Calculated runoff depth using Curve Number Method

Used HEC HMS and SWMM to compute and compare runoff depth for the entire site

http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx

http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx

2-Year Storm Hydrographs

2-Year Storm: Pre- Development Runoff Depth: 1.35 in. Peak Runoff Rate: 2.31 cfs

2-Year Storm: Post- Development (no management) Runoff Depth: 2.36 in. Peak Runoff Rate: 3.89 cfs

25- Year Storm Hydrographs

25-Year Storm: Pre- Development Runoff Depth: 3.77 in. Peak Runoff Rate: 7.07 cfs

25-Year Storm: Post- Development (no management) Runoff Depth: 5.23 in. Peak Runoff Rate: 8.95 cfs

Alternative Design Options Traditional stormwater detention basin

Stormwater wetland

LID techniques

Space Required (acres) Aesthetics Ecological Impact Cost

Detention Basin 0.9 Poor Significant disturbance of

natural plant life $ 158,200.00

Stormwater Wetland (alone) 1 Good

Provides new habitat, provides great filter for

water quality, groundwater recharge

$ 174,300.00

LID Techniques 0.5 Excellent

Groundwater recharge, reduce urban heat island,

pollutant reduction, enhanced habitat/minimal

disturbance, increased biodiversity

Variable

Approach Selection: LID Techniques Multifunctional

Enhance appearance of community

Mimic natural infiltration process – water quality

For design purposes we will break the site down into:

• Average individual lots

• Public area

Average Residential Lot

Lot Area: 4,857 ft2

Roof Area: 1,133 ft2

Driveway Area: 527 ft2

Garage Area: 264 ft2

40% of the residential lot is impervious

Robinson Design Engineers: Site Layout

Average Residential Lot

The following 5 LID techniques were evaluated: • Vegetative roof • Rain barrels • Permeable pavement • Infiltration trench • Rain garden Analytical evaluation methods: • Hand calculations • SWMM 5.1

Vegetated Roof: Design Considerations Initial Growth of Vegetation

Avoiding Leaks

Cost of Materials

Access to Roof- Maintenance

Pitch of Roof

Gutter System

Structural analysis of roof

http://www.jrsmith.com/uploads/fileLibrary/1010_rdp_lg.jpg

http://i.stack.imgur.com/tW8B8.jpg

Vegetative Roof Holding Capacity Designed to hold 50% of the amount of water falling on the

roof during a 2-year storm

Each layer of a vegetative roof has a certain water capacity

Total Water Storage: 195 ft3

Component Water Holding Capacity Total

Plants - -

Media Layer 40%, 4 inches 148.7 ft3

Filter Fabric - -

Drainage Layer 8 L/m2 32.3 ft3

Root Protection Layer 4 L/m2 14.8 ft3

Waterproof Layer - -

Roof Material - -

Rain Barrels Balance between aesthetics and

storage 1800 gallons roof runoff (2 yr.storm)

2700 gallons roof runoff (25 yr. storm)

Linked barrels increased volume without overwhelming size

Tank Volume: 200 gallon tanks

Dimensions: 47’’height, 36’’ diameter

To be placed on both the house and garage

Total Storage Capacity: 800 gallons (4 barrels total)

Overflow management: Automatic Downspout Diverter

http://gardenwatersaver.com/connector-kits/

http://www.gardeners.com/buy/downspout-diverter/33-991VS.html

Infiltration Trench Underground water storage and

infiltration feature

Coarse gravel surrounded by filter fabric and topped with soil

Space on lot

Surface Area: 730 ft2

(25% of yard)

Water storage = 𝑆𝑢𝑟𝑓𝑎𝑐𝑒 𝐴𝑟𝑒𝑎 × 𝐷𝑒𝑝𝑡ℎ × 𝑉𝑜𝑖𝑑 𝑆𝑝𝑎𝑐𝑒

= 875 ft3

Lined with filter fabric

http://www.riversides.org/websiteimages/fig421infiltrationtrench_400.gif

Permeable Pavement • Components:

• Subsurface gravel storage (12-18’’) • Pavement • Filter fabric lining

• Main decision is pavement type • Storage depth: 18 inches • Storage volume: 342 ft3

http://www.stormwaterpa.org/assets/media/BMP_manual/chapter_6/Chapter_6-4-1.pdf

Permeable Pavement • Pavement Options

Considered: • Single Sized Aggregate

(gravel) • Interlocking Concrete

Pavers • Recycled Glass Porous

Pavement (FilterPave) • Recycled Rubber Tire

(PorousPave)

• Evaluated on: • Sustainability • Porosity • Maintenance • Cost

http://www.porouspaveinc.com/projects/gallery/drive

ways-gallery/ http://filterpave.com/prairie-crossing#jp-carousel-481 http://www.landscapeonline.com/research/article/17729

http://www.islandhopperlandscape.com/imgshop/Image/Bulk%20Materials/Decorative%20Gravel/Hudson%20Valley%20Gravel.jpg

Recycled Pavement Options Compared PorousPave

Sustainability: 50% recycled tire, 50% crushed stone

aggregate Held together by urethane

Porosity: 29% void space

Cost: $6.95/ft2

Maintenance: Spray clean of debris with garden hose

http://applelandscapemgt.com/wp-content/uploads/2013/05/pso-porous-pave-seminar-

004.jpg

FilterPave Sustainability:

50% recycled glass, 50% stone Proprietary pigmented binder

Porosity 39% void space

Cost: $8.50 - $16.00/ft2

Maintenance: Flush and Vacuum annually Reapply UV stabilizing topcoat every 2-3

years

http://filterpave.com/evergreen-arboretum-everett-washington#jp-carousel-476

http://www.alaskapublic.org/wp-content/uploads/2012/05/20120515-Glass-

Recycling-13.jpg

http://upload.wikimedia.org/wikipedia/commons/d/d7/Tires_in_forest.jpg

Rain Garden Surface Area: 300ft2

Depth: Soil storage depth: 3 ft Ponding depth: 8 in. Freeboard: 4 in.

Desired soil composition: At least 50% sand for infiltration

Existing soil: 95% sand 5% silt Void Space: 0.4312

Storage: 342 ft3 http://img2-3.timeinc.net/toh/i/g/11/yard/08-garden-landscaping/rain-garden-x.jpg

Residential Lot: LID Evaluation

LID Selection: • Rain Garden • Permeable Pavement

Green Roof

Permeable Pavement

Infiltration Trench

Rain Garden

Rain Barrels (4)

Storage Capacity (ft3) 196 342 875 342 107

Practicality and Operation

Fair Good Fair Good Fair

Price $5,700.00 $5,500.00 $5,500.00 $925.00 $1,170.00

Storage Capacity (ft3)

Porous Pavement & Rain Garden

684

Required 664

Final Design: Rain Garden Specs:

Total depth: 4 ft. Ponding depth: 8 in. Freeboard: 4 in.

Surface Area: 300 ft2

Soil Media: Existing is 95% sand, 5% silt Depth: 3ft.

Plant Selection:

Beautyberry, Palmetto Dwarf, Purple Coneflower

Other considerations: 10 ft. from foundation –

eliminate risk of seepage

AutoCad Drawing: Kelly Creswell

Final Design: Permeable Pavement Specs:

PorousPave – 50% recycled tire rubber, 50% crushed stone 29% void space

Subsurface depth: 18’’

Filter fabric liner – 100% post consumer recycled plastic bottles

AutoCad Drawing: Kelly Creswell

Sample Lot Layouts

Drawn by Kelly Creswell

Drawing by RDE

Public Area

Public Area

LID Selection: • Bio-retention Cells • Constructed Wetland • Vegetated Swale • Infiltration Trench

Public Area Layout

Drawn by Daniel Chewning

Final Design: Bioretention Cells Specs:

Total Surface Area: 3,785 ft2

Cell 1: 1200 ft2

Cell 2: 1500 ft2

Cell 3: 1085 ft2

Drawdown time:

54 in/(2 in/hr) = 27 hr < 72 hour requirement

Plants: White wild indigo, Orange cone flower, Saw palmetto, Elderberry, Eastern red cedar

Drawing by Kelly Creswell

Final Design: Infiltration Trench

Drawn by Kelly Creswell

• Specs: • Depth: 3 ft of 1-2’’ gravel

• 4’’ of native soil replaced on top allows for growth of grass

• Filter fabric: 100% post consumer material – from recycled plastic bottles

Final Design: Vegetative Swale Planting: Native grass mix for

Southeastern U.S. - contains Virginia Wildrye, Purpletop, and Broomsedge

http://www.nativegrasses.com/images/grasses/SEGR-2.jpg Drawn by Kelly Creswell

Design: Manning’s Equation

𝑉𝑚𝑎𝑥 =1.49

𝑛𝑅2/3𝑆1/2

𝑛 = 0.05 𝑉𝑚𝑎𝑥 = 4 𝑓𝑡/𝑠

Shear Stress Equation 𝜏𝑚𝑎𝑥 = 𝛾𝑅𝑆𝑓

𝜏𝑚𝑎𝑥 = 2.1 𝑙𝑏/𝑓𝑡 for native grass mix

Final Design: Constructed Wetland Design:

Available space

Water storage

Drawn by Daniel Chewning https://www.rose-hulman.edu/csd/ESL/reports/CH3_STConstWLSwWetland.pdf

Final Design: Connecting Infrastructure Culverts

𝑄 =1

𝑛𝐴𝑅

2

3𝑆1

2

Designed using peak flowrate determined in SWMM

4 culverts needed 1- 23 x 14 3- 30 x 19

Riprap Sizing

V=1

𝑛𝑅

2

3𝑆1

2, maximum permissible velocity of the swale

𝑛 =𝑑

16

21.6𝑙𝑜𝑔10𝑑

𝐷50+14.0

D50 = 5 in and 3 in

Drawn by Tyler DuBose

http://www.gravelatlanta.com/images/riprap.gif

Final Design: Outlet Specs:

Cannot exceed 2 and 25 year storm flowrates 2 yr – 2.31 cfs

25 yr – 7.07 cfs

Weir control

3 stage weir box

• Design • Forward Finite Difference

• SWMM runoff flow rates

• Reduced time step to improve resolution

Drawn by Daniel Chewning

SWMM Model

http://www.hydraulicmodel.com/sites/hydraulicmodel.com/files/images/epa_logo_1_2.thumbnail.png

EPA SWMM, Tyler Dubose

Post development final design: 2 year storm

Post development final design: 25 year storm

Life Cycle Assessment Material Transportation Embodied Energy Carbon Emissions Comments

Filter Fabric 264.92 MJ/ton N/A N/A Recycled PCW

Plants Minimal N/A Negative

PorousPave 264.92 MJ/ton N/A N/A 50% tire/stone

Mulch 18.834 MJ/ton N/A 20 tons 99.98% reduction in CO2

Gravel/Riprap 18.834 MJ/ton 0.5 MJ/kg 0.0018 kg/kg

Concrete 27.594 MJ/ton 1.3 MJ/kg 0.1311 kg/kg

LCA Cont. Ecological – goal of zero impact on the runoff volume

coming from the site as a means of maintaining the existing ecosystem

Social – ultimately serves the people living in the development. Promotes an active lifestyle and provides an educational opportunity.

Economic – prevents future flooding and erosion

Ethical– aim to balance the wishes of the clients and the biological integrity of the site

Sustainability Efficiency

Capture 100% of excess runoff on site for design storm

Societal Issues Emphasis on public open space creates a sense of community

and equality Allows for development of relationships between neighbors

Carbon and Water footprint Minimal carbon emissions

Minimal energy input after construction Plants will sequester carbon Carbon emission during construction phase only

Water footprint Aid in groundwater recharge

Conclusions Goals

Prevent post-development flow rates and volumes from exceeding pre-development levels

Design

Met flow rate and volume requirements

Provided ecologically and socially beneficial stormwater management

Budget Porous Pavement

Excavation $25/yd3 734.7

PICP $6.95/ft2 3666.13

Gravel $55/yd3 1073.50

Filter Fabric $0.15/ft2 99.75

Total 5474.33

Infiltration Trench

Gravel $55/yd3 5093.00


Filter Fabric $0.15/ft2 840.00

Total 12908

Bioretention Cell


Plants Estimated 1500.00

Mulch $40/yd3 616.66

Total 9156.76

Rain Garden

Mulch $40/yd3 110.00

Plants Estimated 800.00


Total 923.95

Vegetative Swale


Seeding $2.40/yd2 655.7458

Total 8177.586

Culvert and Outlet Structure

Elliptical Pipe $82/linear ft 9840

Concrete for Outlet Structure $4.25/ft3 127.50

Constructed Wetland

Excavation $25/yd3 23920

Plants Estimated 2000

Total 25920

Total $ 219,688.44

Timeline

Event 9/8 9/10 9/17 9/24 10/1 10/7 10/8 10/15 10/22 10/29 11/5 11/12 11/19 11/26 12/3

FinishProposal

PresentProposal

FinishmajorityofLiteratureReview

PickDesign

StartWritingMidtermPaper

3-weekprogressreport

DeveloppreliminaryDesign

CalculationsforDesign

FinishWritingMidtermpaper

MidtermPresentationandpaperdue

CostAnalysisforDesign

Bringtogetherfinaldesign

WriteFinalPaper

FinalPresentation

References Alexander, M.D., Barfield, B.J., Bates, B/T/, Chalavadi, M., Harp, S.L., Hayes, J.C., Stevens, E. 2008. Modeling Impacts of Post Development Water Quality BMPs. 21st Century Watershed Technology: Improving Water Quality and Environment, Proceedings of the 29 March-3 April 2008 Conference. Best Management Practices Handbook. South Carolina Department of Health and Environmental Control. www.scdhec.gov/Environment/waterquality/stormwater/BMPHandbook/ Blount, J., Storey, A., Talbott, M.D. 2011. Harris COunty Low Impact Development Green Infrastructure Design Criteria for Stormwater Management. Adopted by Harris County Commissioners Court. Bosch, T., Borghi, V., Watson, J., Miranda, M. 2004. Life Cycle Assessment of PVC and of Principal Competing Materials. Commissioned by European Commission.

Burke, M.K., Hitchcock, D.R., Lewitus, A.J., Strosnider, W.H., 2007. Predicting Hydrology in Wetlands Designed for Coastal Stormwater Management. An ASABE Meeting Presentation, Paper Number 077084. Bonta, J.V. 2012. Managing Landscape Disturbances to Increase Watershed Infiltration. American Society of Agricultural and BIological Engineers. 56(4): 1349-1359. Carolina Yards Plant Database. 2014. Clemson University Cooperative Experience.

Clary, J., Earles, A., Poresky, A., Strecker, E. 2011. Technical Summary: Volume Reduction. International Stormwater Best management Practices (BMP) Database. Clary, J., Hobson, P., Leisenring, M. 2012. TSS, Bacteria, Nutrients, and Metals. International Stormwater Best Management Practices (BMP) Database Pollutant Category Summary. Darnault, C., 2014. Ecological Engineering Class Notes. Unpublished.

DuPont. 2014. Sonora Life Cycle Assessment.

Extensive Green Roofs: Design and Installation Guide. Nophadrain. Dutch Green Building Council.

Fangmeier, D.D., Elliot, W.J., Huffman, R.L., Workman, S.R. 2013. Wetlands. Soil and Water Conservation Engineering. Seventh Edition. 287-302. Fangmeier, D.D., Elliot, W.J., Huffman, R.L., Workman, S.R. 2013. Precipitation. Soil and Water Conservation Engineering. Seventh Edition. 31-54. Fangmeier, D.D., Elliot, W.J., Huffman, R.L., Workman, S.R. 2013. Infiltration and Runoff. Soil and Water Conservation Engineering. Seventh Edition. 81-111.

Green Roofs. Low Impact Development in Coastal South Carolina. North Inlet- Winyah Bay: National Estuarine Research Reserve.

Hammond, G., Jones, C. http://www.uea.ac.uk/~e680/energy/NBS-M016/ICE%20Version%201.6a.pdf ** Edit

Infiltration Trenches. Minnesota Urban Small Sites BMP Manual. Metropolitan Council / Barr Engineering Co.

Kaemmerlen, B. 2008. Fuss & O’Neill. LCSC Rain Garden Workshop.

Klotz, L., 2013. Sustainable Construction Class Notes. Unpublished. Jaber, Woodson, LaChance, and York. Texas A & M AgriLife Extension. Stormwater Management: Rain Gardens.

Robinson, J., 2014. Personal Communication.

Mariam, A., Gozde, O., Ramazan, K., Rajedran, Hodzic, A. Life Cycle Assessment of Particulate Recycled Low Density Polyethylene and Recycled Polypropylene Reinforced with Talc and Fiberglass. Academia.edu.

Minnesota Urban Small Sites BMP Manual. Metropolitan Council / Barr Engineering Co.

Mille, C. 2012. Extensive Vegetative Roofs. Whole Building Design Guide.

Prince George’s County, Maryland. 1999. Low Impact Development Hydrologic Analysis. Department of Environmental Resources Programs and Planning Division.

Raja, F.D., Vijayaraghavan, K. 2014. Design and Development of Green Roof Substrate to Improve Runoff Water Quality: Plant Growth Experiments and Adsorption. Water Research, 63: 94-101. UN WCED. 1987. Our Common Future. Report of the World Commission on Environment and Development. New York, NY. United Nations, World Commission on Environment and Development.

Virginia Division of Environmental Quality. 2011. Bioretention, Stormwater Design Specification No. 9.

Questions?

Robinson Design Engineers