Mitch Woodward, Area Specialized Agent [email_address] Wake County 4001-E Carya Dr Raleigh, NC 27610-2914 (919) 250-1112
Urban Water Quality Issues North Carolina Cooperative Extension Backyard Rain Garden Program: Lessons Learned
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 Rice Creek Watershed District Storage Infiltration
Rain Gardens Can Be Welcome Additions to Landscapes!!!
Design Principles of Rain Gardens <ul><li>Handles stormwater at its source . </li></ul><ul><li>Decreases the velocity of water flowing from impervious surfaces. </li></ul><ul><li>Improves water quality before it enters the stream or ditch. </li></ul><ul><li>Keeps water on the surface aiding infiltration Cost effective (average $2-$3 per sq ft) </li></ul>
Rain garden benefits <ul><li>Add beauty (and value) to your property </li></ul><ul><li>Minimizing rainwater runoff to storm drains or streams while allowing excess rainwater to filter slowly into the soil </li></ul><ul><li>Protecting our valuable water resources </li></ul><ul><li>Provide wildlife habitat </li></ul><ul><li>Adaptable to other community problem areas </li></ul>
Match $$$ provided by involving County Extension Agents $ ….. I’m just matching funds to you, aren’t I?
Target: Homeowners <ul><li>Homeowner Workshops - ‘How To’ Rain Garden </li></ul><ul><ul><li>Stormwater Management </li></ul></ul><ul><ul><li>How to Build </li></ul></ul><ul><ul><li>Which Plants Work Best </li></ul></ul><ul><ul><li>Maintenance Issues </li></ul></ul><ul><li>Rain Garden Events with Sign Up </li></ul><ul><li>Site visits and data collection </li></ul><ul><li>Installation Cost-Share Offered </li></ul><ul><li>Follow-up to see maintenance issues and healthy plants </li></ul>
Homeowner Education: Garden Location & Installation <ul><li>Where does water flow ? </li></ul><ul><li>Where does water travel or collect? </li></ul>Observe your yard during a rainfall event
Site Visits and Data Collection <ul><li>Source and path of stormwater </li></ul><ul><li>Size of impervious surfaces </li></ul><ul><li>Soils type (sandy, clayey, rocky or mixed) </li></ul><ul><li>Proximity to wells, foundations, septic systems </li></ul><ul><li>Existing landscape features </li></ul>
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 Chart 5 % Impermeable Surface Area Rain Garden Size Potential Rain Garden Dimensions (ftXft) 800 ft 2 40 ft 2 4X10, 5X8, 6X7 1000 ft 2 50 ft 2 5X10, 6X8 1200 ft 2 60 ft 2 4X15, 5X12, 6X10, 8X8 1400 ft 2 70 ft 2 5X14, 7X10 1600 ft 2 80 ft 2 7X12, 8X10, 9X9 1800 ft 2 90 ft 2 6X15, 7X13, 8X12, 9X10
Summary of Preliminary Analysis of Raingarden Condition. Rain gardener Type Rain garden Condition*______ Good Fair Failure Avid 10 3 1 Gardener Environmentalist 2 7 Direct Connection 4 4 To Resource Flooding 2 3 Issues Required by Law 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