Sea Aire StormwaterAustin Balser, Daniel Chewning,

Kelly Creswell, Tyler DuBose

IntroductionOverview

ProblemGoalsConstraints

Literature ReviewGoverning EquationsConcept Review

Sustainability Timeline References

ProblemRecognition:

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

Definition: High volume of runoffIncreased pollutant load

GoalDesign a stormwater management plan for

Sea Aire subdivision that:Meets state regulations by ensuring the peak

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

Ensures the post-development runoff volume doesn’t exceed pre-development levels

Constraints Ecological: Must work with existing soil,

water table, vegetation, and waterwaysUltimate use: Residential living and

recreational spaceSkills: Limited knowledge and experience with

stormwater design Cost: Budget of $1200 for design process.

Must account for travel expenses, software, and testing services

Additional: Difficulty working with regulators and contractors

Questions of User, Client and DesignerUser – 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 EngineersWill this meet regulations?Will it cost more?

Designer – The design team and RDEWill this be long lived?Can this be an amenity?

Governing EquationsEnergy Balance

General Form Mass Balance

Curve Number Method,

Horton’s Equation

Universal Soil Loss EquationT=RKLSCP

Stormwater ManagementConventional Methods versus LID

methodsConventional 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

Comparison of Volume

1 – Pre-development 2 – Conventional Methods3 – LID Methods

LID methods maintain pre-development runoff volume while conventional methods lead to increased volume

Conventional MethodsDetention basinsDrainsConcrete ditchesCulverts

Low Impact Develop MethodsGreen roofsRain water collectionConstructed WetlandsBioretention cellsRain gardensVegetated extended detention basins

Constructed WetlandsPublic area of development

will need a way to catch and retain stormwater

Help filter and remove containments, “Nature’s Kidney”

Shallow depression in the ground with a level bottom

SustainabilityEcological – 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

SustainabilityEfficiency

Capture 100% of stormwater runoff on site for design storm

Carbon and Water footprintCarbon negative

Gravity fed systems Plants will sequester carbon

Potential for decreased freshwater demands due to rainwater recycling (rain barrels)

TimelineEvent 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

Finish ProposalPresent Proposal

Finish majority of Literature ReviewPick Design

Start Writing Midterm Paper3- week progress report

Develop preliminary DesignCalculations for Design

Finish Writing Midterm paperMidterm Presentation and paper due

Cost Analysis for DesignBring together final design

Write Final PaperFinal Presentation

Referenceshttp://landstudy.org/Resources.htmlFangmeier, D.D., Elliot, W.J., Huffman, R.L.,

Workman, S.R. 2013. Wetlands. Soil and Water Conservation Engineering. Seventh Edition. 287-302.

Best Management Practices Handbook. South Carolina Department of Health and Environmental Control. www.scdhec.gov/Environment/waterquality/stormwater/BMPHandbook/

Questions?