Urban Stormwater Management - University of California ... · Site suitability analysis Hydrologic analysis Implementation Recommendations Case Studies ... hydrograph Collect, disperse

Urban StormwaterUrban StormwaterManagementManagement

Rebecca LeonardsonRebecca Leonardson

Rui TelesRui Teles

Brooke Ray SmithBrooke Ray Smith

IntroductionIntroduction

Stormwater in PortugalStormwater in PortugalWhy urban stormwater is currently aWhy urban stormwater is currently aproblemproblem

What is green stormwater management?What is green stormwater management?

Why it is importantWhy it is important

Policy Framework for DecisionmakersPolicy Framework for DecisionmakersSite suitability analysisSite suitability analysis

Hydrologic analysisHydrologic analysis

Implementation RecommendationsImplementation Recommendations

Case StudiesCase StudiesBombarral Bombarral –– downtown revitalization downtown revitalization

Vilar Vilar –– hillside hamlet growth hillside hamlet growth

Existing ProblemsExisting Problems

FloodingFlooding

November 2006November 2006

River PollutionRiver Pollution

Street oil/trash runoffStreet oil/trash runoff

Sewage DischargesSewage Discharges

New DevelopmentsNew Developments

More runoffMore runoff

Downstream impactsDownstream impacts

BombarralBombarral

VilarVilar

Opportunity sites...

What is Green What is Green StormwaterStormwaterManagement?Management?

Definition:Definition:

Non-mechanized Non-mechanized stormwaterstormwater collection, conveyance, detention, collection, conveyance, detention,treatmenttreatment

Benefits:Benefits:

Reduces flood riskReduces flood risk

Reduces pollution of streams and water supplyReduces pollution of streams and water supply

Creates habitat and enhances ecosystem functionCreates habitat and enhances ecosystem function

Improves landscape beauty of a townImproves landscape beauty of a town

Types and Purposes of GreenTypes and Purposes of GreenStormwaterStormwater Management Management

Rainwater collectionRainwater collection

DetentionDetention

ConveyanceConveyance

InfiltrationInfiltration

TreatmentTreatment

Re-useRe-use

Examples of Green Examples of Green StormwaterStormwaterManagementManagement

Green walls, Green roofs

for water collection


Cisterns for water

collection & storage

CBF Merrill Environmental Center, Annapolis, MD

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ce: w

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Cistern Detail

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Rainwater & greywater creative re-use

10th at Hoyt Courtyard, Portland, OR

Bombarral example here


Swales to channel and

convey stormwater

Clean Fill

Subsurface Collection

Clean Fill

ContaminationExisting Soil

Parking Lot, Livermore, CA


Planted swaled to infiltrate

stormwater

Swale, Cross Section

Sour

ce: C

ity o

f Por

tland

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ity o

f Por

tland


Permeable paving for infiltration


Constructed wetlands

to reduce pollution into rivers


Tree planters to

infiltrate and treat

stormwater

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ands

cape

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Suitability AnalysisSuitability Analysis

OpportunitiesOpportunities

Underutilized areas (old buildings, vacant land)Underutilized areas (old buildings, vacant land)

Existing pervious areas (agriculture, parks)Existing pervious areas (agriculture, parks)

Flood-prone areas (low elevation, in floodway)Flood-prone areas (low elevation, in floodway)

ConstraintsConstraints

Built-out urban core (no infiltration)Built-out urban core (no infiltration)

Steep slopes (no detention/treatment)Steep slopes (no detention/treatment)

??

SuitabilitySuitabilityAnalysis:Analysis:BombarralBombarral

AerialAerial

Suitability AnalysisSuitability Analysis

Topo map, slope map hereTopo map, slope map here

SuitabilitySuitabilityAnalysis:Analysis:

BombarralBombarral

Flood AreasFlood Areas

SuitabilitySuitabilityAnalysis:Analysis:BombarralBombarral

UnderutilizedUnderutilizedAreasAreas

SuitabilitySuitabilityAnalysis:Analysis:

BombarralBombarral

Green /Green /PermeablePermeable

AreasAreas

BombarralBombarralCase Study:Case Study:

Sewer &Sewer &StormwaterStormwater

NetworkNetwork


Sewer &Sewer &StormwaterStormwater

OutfallOutfallLocationsLocations


TreatmentTreatmentOpportun-Opportun-

itiesities


TreatmentTreatmentOpportun-Opportun-

itiesities


StormwaterStormwater&&

WastewaterWastewaterTreatmentTreatmentOpportun-Opportun-

itiesities

Stormwater Treatment:Stormwater Treatment:Detention & Infiltration TypologyDetention & Infiltration Typology

Drainage Area: 305,000 m2

Peak Flow (1yr 1hr storm): 0.4 cms

Stormwater runoff volume (20yr 24hr storm): 11,721 m3

Existing Basin Size (at 0.45m depth): 1,300 m2

(could detain 100% if 2m deep)

Wastewater Treatment:Wastewater Treatment:Bank Setback TypologyBank Setback Typology

Wastewater Treatment:Wastewater Treatment:Urban TypologiesUrban Typologies

Policy AnalysisPolicy Analysis

Potential Funding SourcesPotential Funding Sources

Developer fees -Developer fees -

Developer incentives Developer incentives –– lower taxes lower taxes

Policy StrategiesPolicy Strategies

Performance measures for new developmentPerformance measures for new development

Case Study: BombarralCase Study: Bombarral

Urban Design Strategy (diagram & calculations)Urban Design Strategy (diagram & calculations)

Future Development Strategy (diagram &Future Development Strategy (diagram &

calculations)calculations)

Outfall Area Treatment StrategyOutfall Area Treatment Strategy

Case Study: VilarCase Study: Vilar

Urban Design Strategy (diagram & calculations)Urban Design Strategy (diagram & calculations)

Future Development Strategy (diagram &Future Development Strategy (diagram &

calculations)calculations)

ConclusionsConclusions

Stormwater StrategiesStormwater Strategies

Treatment wetlands, infiltration basinsUrban runoff water

quality

Stormwater BMPs: infiltration basins, planted

gutters/swales, cisterns

Flooding - over

AdO pipe capacityVilar

Treatment wetlandsUrban runoff water

quality

Best Management Practices (BMPs): green roofs,

cisterns, swales, performance measures

Future

Development &

Retrofitting

Reduce peak flow (temporary removal):

detention/treatment basins, swales

Rainwater reuse (permanent removal): cisternsFlooding - sewer

backflow

Bombarral

Solution Strategies

Existing

Stormwater

Challenges

Location

PurposePurposeTypeType

Improve water qualityImprove water quality

Reduce peak flow into systemReduce peak flow into system

TreatmentTreatment

InfiltrationInfiltration

ConveyanceConveyance

Rainwater collection /Rainwater collection /

GreywaterGreywater re-use re-use

DetentionDetention

Reduce volume into systemReduce volume into system




Reduce municipal water useReduce municipal water use

Reduce volume into systemReduce volume into system


Types and Purposes of GreenTypes and Purposes of GreenStormwaterStormwater Management Management

http://www.valveandequipment.com/catalog/images/tf2.gif

Backflow

prevention

Drainage standards for newDrainage standards for newdevelopment (from Seattle)development (from Seattle)

Reduce impervious surfaces to 50% overallReduce impervious surfaces to 50% overall

Control the 3 yr., and 25 yr, 24 hour stormControl the 3 yr., and 25 yr, 24 hour storm

Retain existing vegetationRetain existing vegetation

Protect river by matching the pre developmentProtect river by matching the pre developmenthydrographhydrograph

Collect, disperse and retain the roof runoffCollect, disperse and retain the roof runoff

No directly connected impervious areas (eitherNo directly connected impervious areas (eitheruse pervious paving or bioretention)use pervious paving or bioretention)

Documents

Urban Stormwater Management - University of California ... · Site suitability analysis Hydrologic analysis Implementation Recommendations Case Studies ... hydrograph Collect, disperse