3/26/2011

1

DavidDodsURSCorp.,OverlandPark,KS

Photos: David Dods

Year 5

3/26/2011

2

Lessons: With some care and help from us, Mother Nature has an amazing ability to restore degraded lands and waters.

It All Begins with Regional Planning and Site DesignIt All Begins with Regional Planning and Site Design

RainGardensRainGardens Shallow gardens with plants that tolerate periodic saturation

Dry out in a day or two

Restore hydrologic function to the landscape

Habitat

Photo: Barr Engineering; Illustration: Dan Shaw

Attractive Landscaping

Planting Beds Planting Beds --Two ApproachesTwo Approaches

Native Soil

Rain Garden

Engineered Soil + UnderdrainBioretention

Illustrations: Dan Shaw, Waterdrop Innovations; Barr Engineering

3/26/2011

3

Rain Garden Examples:Rain Garden Examples:Common ApplicationsCommon Applications

Photos: David Dods, URS Corp.

Downspout Driveway

Park & Landscape FeaturesPark & Landscape Features((Filtering runoff to protect park lake)Filtering runoff to protect park lake)

Photo: Rusty Schmidt, Waterdrop InnovationsDesign by BNIM Architects

3/26/2011

4

Parking Lot EdgeParking Lot Edge

Photo: David Dods, URS

Parking Lot IslandParking Lot Island

Photo: David Dods

Driveway RunoffDriveway Runoff

Photo: David Dods

Street EdgesStreet Edges

Photo: Rusty Schmidt, Waterdrop Innovations

3/26/2011

5

Design & Photo by BNIM Architects

Water Soil

RainGardenDesignRainGardenDesign1.1. Define Project GoalsDefine Project Goals2.2. Site AnalysisSite Analysis3.3. SizingSizing4.4. Garden Bed Garden Bed

PreparationPreparationl ll l

Plants

5.5. Inlets & OutletsInlets & Outlets6.6. Mulch, Edging, & Mulch, Edging, &

Finishing TouchesFinishing Touches7.7. Care & MaintenanceCare & Maintenance8.8. PlantsPlants

Define Project GoalsDefine Project Goals

What is the purpose of the rain garden?What is the purpose of the rain garden?

yy Remove specific pollutantsRemove specific pollutantsyy Provide detention & volume controlProvide detention & volume controlyy G d t hG d t hyy Groundwater rechargeGroundwater recharge

Design depends upon the goalsDesign depends upon the goals

3/26/2011

6

LocationsLocations Catch Runoff Near the Catch Runoff Near the

SourceSource

Avoid End of Pipe or Avoid End of Pipe or Bottom of the HillBottom of the Hill

Evenly Spread Across theEvenly Spread Across the

Photos: Barr Engineering (L), Portland Stormwater Manual (R)

Evenly Spread Across the Evenly Spread Across the SiteSite

Small Drainage Areas ~ 1 Small Drainage Areas ~ 1 acre or lessacre or less

Catch Water Before it Picks Up Lots of Speed

Where does the water come from?

Where does it flow?

Above-Ground Obstructions: Trees, Power Lines, Structures, Walking Paths, etc.

Below-Grade Utilities: Call in a Utility Check

Utilities

Uphill of Buildings on Slopes

Photo: David Dods

Behind Structural Retaining Walls if Not Designed for Water

y Soil Types & Compactiony Depth to Groundwater and Bedrock

Photo: Barr Engineering

Note asphalt layers

3/26/2011

7

Percolation TestPercolation Test Time how fast the water goes down

How many inches soak away in 24-36 hrs

Illustration: Marjorie Vigoren, City of Plymouth, MNPhoto: Barr Engineering

Runoff VolumeRunoff Volume =

Precip x Drainage Area x Runoff Coeff.

Parking Lot

Building,w/ Flat Roof

Turf

Land Use & Runoff CoefficientsLand Use & Runoff Coefficients(Small Storm Hydrology Method)(Small Storm Hydrology Method)Runoff Coefficients Vary by Land Use and Storm Event Size

Roof

Rv = 0.87 0.23 0.98

(for 1.4 in. storm event)

D th

Length x Width

DepthVolume

3/26/2011

8

When to Use Engineered Soils (When to Use Engineered Soils (BioretentionBioretention))y If not enough area is available for a rain garden, bioretention

can use less spacey Engineered soils drain faster, so the garden can be deeper

and not as widey Meet specific pollutant filtration goal

Max Depth~ 18 (typ)

Garden ExcavationGarden ExcavationKeep Equipment Out of Keep Equipment Out of

Garden toGarden toAvoid CompactionAvoid Compaction

Photos: 1) Kevin Slates, URS, 2) Barr Engineering

Bed Shape:Bed Shape:FlatFlat--Bottomed BowlBottomed Bowl

Illustrations: Dan Shaw, Waterdrop Innovations

Source: The Blue Thumb Guide to Raingardens, by Schmidt, Shaw, & Dods

Garden Bed PreparationGarden Bed PreparationUsing Native SoilsUsing Native Soils

Dig out basic bed shape

Rip & Break up

Photograph: Carla Dods

compacted soils

Till in 3 4 inches compost

Rake out to final shape

3/26/2011

9

Photo provided by: Rusty Schmidt

ReRe--test Infiltration Before Plantingtest Infiltration Before Planting

Photograph: Carla Dods

PlantingPlanting

Photographs: Carla Dods and David Dods

MulchMulchUse Coarse, Double-

Shredded Hardwood

Pinebark Nuggets & Cedar Chips Float

Photos: David Dods

3/26/2011

10

OnOn--Line vs. OffLine vs. Off--Line DesignsLine Designs

On-Line

Off-Line

Off-Line Reduces Erosion Problems

OffOff--Line DesignLine Design

Garden Full

System Overflow

Photographs courtesy of Barr Engineering

Photo: David Dods, URS

Curb Cut, Grass Filter Strip, & Splash PadCurb Cut, Grass Filter Strip, & Splash Pad

Depress Sod below curb

Photo: Barr Engineering

3/26/2011

11

Curb Cut and Sediment Curb Cut and Sediment ForebayForebay

Photo: Barr Engineering

Temporary Bypass During Plant Temporary Bypass During Plant EstablishmentEstablishment

Sandbags to Divert Flow

Photo: Barr Engineering

Outlets:Outlets: Make sure overflows from large Make sure overflows from large storms have a controlled discharge pointstorms have a controlled discharge point

Photo: Rusty SchmidtManhole with a riser

Finishing TouchesFinishing Touches

BordersandEdging:MaketheGardenLookDeliberate

Photographs: Carla Dods; Rusty Schmidt

3/26/2011

12

Maintenance: Maintenance: Typical Landscaping RequirementsTypical Landscaping Requirementsy Weed: 4-5x 1st yr, 3x 2nd yr, then 2x/yr y Prune & Mulch: Annuallyy Clean sand & debris at inlet: 2x/yr

Photo: Barr Engineering

Results of a Successful Garden: Results of a Successful Garden: Infiltration Improves Each Year (Infiltration Improves Each Year (siltysilty clay soils)clay soils)

Lawn:3 / Day

Photo: David Dods

3 / Day

Raingarden:3 / Hour

Reference: Reference: The Blue Thumb Guide to The Blue Thumb Guide to RaingardensRaingardens

Written for upper Midwest, but principles and many of the plants are Written for upper Midwest, but principles and many of the plants are appropriate for Texas tooappropriate for Texas too

Available from Terrace Horticultural BooksAvailable from Terrace Horticultural Books

www.terracehorticulturalbooks.comwww.terracehorticulturalbooks.com

y Rusty Schmidt, Washington Conservation District, Stillwater, MNy Dan Shaw, Waterdrop Innovationsy Kurt Leuthold and Fred Rozumalski, Barr Engineering,

Mi li MNMinneapolis, MNy Marjorie Vigoren, City of Plymouth, MNy Jim Schuessler, BNIM Architects, Kansas City, MOy Carla Dods

3/26/2011

13

QuestionsQuestions

?

david_dods@urscorp.com,913.344.1022