North Carolina Cooperative Extension Backyard Rain Garden

Program:Lessons Learned

Mitch Woodward, Charles Humphrey, Bill Lord,Dwane Jones, Bill Hunt, Kelly Collins, Lara Rozzell, Wendi Hartup,

Charlotte Glen

Goal:

Pushing Back the Frontiers of Stormwater -

Ignorance

Raingardens slow water runoff and improve water quality

Rainfall

Storage

Infiltration

Rice Creek Watershed District

Rain Gardens Can Be Welcome Additions to Landscapes!!!

Design Principles of Rain Gardens• Handles stormwater at its source.

• Decreases the velocity of water flowing from impervious surfaces.

• Improves water quality before it enters the stream or ditch.

• Keeps water on the surface aiding infiltration Cost effective (average $2-$3 per sq ft)

Rain garden benefits•Add beauty (and value) to your property

•Minimizing rainwater runoff to storm drains or streams while allowing excess rainwater to filter slowly into the soil

•Protecting our valuable water resources

•Provide wildlife habitat

•Adaptable to other community problem areas

NCSU 7 Pilot CountiesNCSU 7 Pilot Counties

Funding Provided by 319

Match $$$ provided by involving Match $$$ provided by involving County Extension AgentsCounty Extension Agents

$…..I’m just

matching funds to you, aren’t I?

Target: Homeowners

• Homeowner Workshops - ‘How To’ Rain Garden Homeowner Workshops - ‘How To’ Rain Garden – Stormwater Management Stormwater Management – How to Build How to Build – Which Plants Work BestWhich Plants Work Best– Maintenance IssuesMaintenance Issues

• Rain Garden Events with Sign Up Rain Garden Events with Sign Up

• Site visits and data collectionSite visits and data collection

• Installation Cost-Share OfferedInstallation Cost-Share Offered

• Follow-up to see maintenance issues and healthy plantsFollow-up to see maintenance issues and healthy plants

Homeowner Education:Homeowner Education: Garden Location & Installation Garden Location & Installation

• Where does water flow ?

• Where does water travel or collect?

Observe your yard during a rainfall eventObserve your yard during a rainfall event

Site Visits and Data Collection

•Source and path of stormwater •Size of impervious surfaces•Soils type (sandy, clayey, rocky or mixed)•Proximity to wells, foundations, septic systems•Existing landscape features

Soil Evaluation

Be Aware of Clay Soils!

If drains less than 1 hour = too fast and plants won’t establish

If drains more than 48-72 hours = too wet ! Backyard wetland?

412 Simerville

Edward Baker

PROBLEM: Water drains directly from roof and lot into pipes, without opportunity for treatment or infiltration.

SOLUTION: This lot is the ideal location for a rain garden, 1) Enhance water treatment capacity by excavating existing native soil and replace w/ high permeability soil. 2) Carefully manage irrigation system to maintain a dryer soil to avoid rain runoff.

Sizing ChartImpermeableSurface Area

Rain Garden Size

Potential Rain Garden

Dimensions(ftXft)

800 ft2 40 ft2 4X10, 5X8, 6X7

1000 ft2 50 ft2 5X10, 6X8

1200 ft2 60 ft2 4X15, 5X12, 6X10, 8X8

1400 ft2 70 ft2 5X14, 7X10

1600 ft2 80 ft2 7X12, 8X10,9X9

1800 ft2 90 ft2 6X15, 7X13,8X12, 9X10

5 %

Rain Garden Installations

Raleigh

Rated as ‘Good’

Day of Installation + 18 Months

Raleigh #2Day of Installation + 3 years

• Fair Condition

• Maintenance issues persist!

Cary

• Fair

• Continues to work well

Fall After Installation After 1 year, 2 inch rain

Durham Museum of Life and Science

• Fair

• Great Demonstration Site

Day of Installation + 18 Months

Project Results• 60+ Gardens treat 1 ac impervious surface• Nitrogen removed over next 20 yrs• 13 Workshops -11 Homeowner, 2 Master Gardener

• Created Local Expertise: Agents - Master Gardener Trainings

• Landscaper Trainings• Demonstrations at Fairs and Museum

• Increased local Interest / Installations

• Strong Website Support• Future opportunities = LID

What didn’t work

Minor Mishaps

Failures

Summary of Preliminary Analysis of Raingarden Condition. Rain gardener Type Rain garden Condition*______

Good Fair Failure Avid 10 3 1Gardener Environmentalist 2 7 Direct Connection 4 4To Resource

Flooding 2 3Issues Required byLaw 8 15 8** Educators / Schools 1 5

*Good: Maintained well, functioning as designed.

Fair: Maintenance not evident, still provide some treatment

Failure: Not maintained, not functioning.

Rain Gardens Maintenance Issues 2 Years after Installation. Maintenance Issue Number of Rain gardens Affected Berm / Weir Failure 6 Plants / Planting 49 Soils / Drainage 10 Sedimentation / 8**Clogging Mulching 38 General Neglect / Abandoned 9

www.bae.ncsu.edu/topic/raingarden