How to Install a Rain Garden at Your Home Name of Location Date What is a Rain Garden? • Shallow landscaped depression that collects and treats stormwater runoff. • Designed to merge two important goals: aesthetics and water quality. • Can be blended into the landscape and made to look natural. • Water is directed into them by pipes, swales, or curb openings. Benefits • Designed to intercept, treat, and infiltrate stormwater at the source before it becomes runoff. • Provides very high pollutant removal efficiencies. • Can be incorporated into the landscapes of many locations, including your home. The Parts of a Rain Garden Your Home The Science Behind Rain Gardens • Absorption to soil particles − Removes dissolved metals and soluble phosphorus • Plant uptake − Removes small amounts of nutrients • Microbial processes NOTE: 90% of all storm events − Removes organics and pathogens produce less than 1 inch of rain. Therefore, the key to reducing • Exposure to sunlight and dryness pollutant loads is to treat the runoff associated with the first 1 − Removes pathogens inch of rain (Clayton & Schueler, • Sedimentation and filtration 1996). − Removes total suspended solids, floating debris, trash, soil-bound phosphorus, some soil-bound pathogens • Infiltration of runoff − Provides flood control, groundwater recharge, and nutrient removal Infiltration of Runoff How much water does a typical rain garden treat in a year? • 90% of rainfall events are less than 1.00” • New Jersey has approx. 44” of rain per year • The rain garden will treat and recharge: 0.9 x 44” = 40”/year = 3.3 ft/year • The rain garden receives runoff from 1,000 sq.ft. • Total volume treated and recharged by the rain garden is 1,000 sq. ft. x 3.3 ft/year = 3,300 cubic feet/year, which is 25,000 gallons/year • Build 40 rain gardens and we have treated and recharged 1 million gallons of water per year! USDA NIFA Rain Garden Video Click here to play video How To Install a Rain Garden at Your Home Steps 1. Planning 2. Installation Mendham Township Elementary School, Morris County 3. Maintenance Planning Steps 1. Planning • Identify Site • Site Visit • Design Calculations Planning Steps Identify Site Things to Remember • The rain garden should be at least 10 feet from the house so infiltrating water doesn’t seep into the foundation. • Do not place the rain garden directly over a septic system. • Do not put rain garden in places where the water already ponds or the lawn is always soggy. • Place in full or partial sunlight as a first option • Select a flat part of the yard for easier digging as a first option. • Avoid large tree roots. http://clean-water.uwex.edu/pubs/raingarden/rgmanual.pdf Planning Steps Identify Site 1. Identify the Drainage Area Before Parking Lot/ Roof Driveway Union County Vocational School Hockman Farm, Winchester, Virginia Planning Steps Identify Site After Parking Lot/ Driveway Roof Union County Vocational School Hockman Farm, Winchester, Virginia Planning Steps Identify Site Parking Lot/ Driveway with a Curb Cut Before After Rutgers Cooperative Extension of Monmouth County, Freehold, NJ Planning Steps Identify Site 2. Drainage Problems Property Flooding Union County Vocational School Planning Steps Identify Site 3. Current Landscaping Practices Union County Vocational School Planning Steps Site Visit 1. Determine Current Stormwater Flow Flow If the area is prone to flooding, it may be difficult to improve the drainage. Union County Vocational School Planning Steps Site Visit 2. Measure Impervious Surface Area (Drainage Area) Surface Area = (L1xW) + (L2xW) = (15’x20’) + (10’x20’) Roof Roof = (300’) + (200’) = 500 square feet L1 L2 W Hockman Farm, Winchester, Virginia Planning Steps Site Visit 2. Measure Impervious Surface Area (Drainage Area) Make observations during storms to estimate the impervious surface Rain Garden area/ drainage area Or use survey equipment Drainage Area Planning Steps Site Visit Rain Garden Sizing Table Based on New Jersey’s Water Quality Design Storm Drainage Size of 3” Deep Size of 6” Deep Size of 8” Deep Rain Garden Rain Garden Rain Garden Area (Clay soils) (loamy soils) (sandy soils) 500 ft2 200 ft2 100 ft2 75 ft2 750 ft2 300 ft2 150 ft2 112 ft2 1000 ft2 400 ft2 200 ft2 149 ft2 1500 ft2 600 ft2 300 ft2 224 ft2 2000 ft2 800 ft2 400 ft2 299 ft2 Planning Steps Site Visit 3. Determine Existing Utility Lines Planning Steps Site Visit 4. Percolation Test Steps: 1. Dig a hole 12 inches deep by 6 inches in diameter. 2. Fill hole with water and let stand until all the water has drained into the ground. 3. Refill the empty hole with water again. Measure the depth of water with a ruler. 4. Check the depth of water with a ruler every hour for 4 hours. 5. Calculate how many inches of water drained per hour. ~1 inch of water draining per hour is good Planning Steps Site Visit 4. Percolation Test 4213stndrdth HourHourHour Ruler Water should be completely drained within 24 hours. Planning Steps Site Visit 5. Soil Test • Sample the soil and send to the a Soil Testing Lab for: • Nutrient analysis/ recommendations • pH analysis/ recommendations • Percent sand/ silt/ clay • Soil Texture Test Roll soil into a ball in hand and see how it forms • Hard ball – Clay/Silt soil • Soft ball – Loamy soil • No ball – Sandy soil Gloucester County 4-H Fairgrounds But, don’t worry – clay/silt and sandy soils can be amended to get the preferred loamy soil texture Planning Steps Site Visit 6. Take Photographs Burlington County Community Agricultural Center Planning Steps Design Calculations 1. General Soil Amendments Amounts for a 100 sq ft Rain Garden that is 6 Inches Deep Soil Amendment Amount for 100 sq ft Rain Garden Sand 1 cubic yard Compost 1 cubic yard Fertilizer Follow Soil Test Result Recommendations Lime Follow Soil Test Result Recommendations Gloucester County 4-H Fairgrounds Planning Steps Design Calculations 2. Approximate Amount of Plants Based on Future Mature Size Size of Rain Approximate Amount Garden of Plants 100 square feet 1 Small Tree (Optional) 7 Shrubs 24 Herbaceous Species 200 square feet 1 Small Tree (Optional) 14 Shrubs 48 Herbaceous Species Leonard Park, Morris County Planning Steps Design Calculations http://plants.usda.gov 3. Types of Plants Facultative Upland (FACU) Facultative Wetland (FACW) Highest Zone/ Lowest Zone/ Ponding Area Upland Area Middle Zone/ Depression Area Facultative Wetland (FACW), Facultative (FAC), Facultative Upland (FACU) Planning Steps Design Calculations Lowest Zone/Ponding Area Native Plants Marsh Marigold Rose Mallow Caltha palustris Hibiscus palustris Planning Steps Design Calculations Middle Zone/Depression Area Native Plants Joe Pye Weed Obedient Plant Eupatorium purpureum Physostegia virginiana Planning Steps Design Calculations Highest Zone/Upland Area Native Plants Black Eyed Susan Bee Balm Rudbeckia hirta Monarda didyma Planning Steps Design Calculations 4. Design of Plant Layout Bradley Beach Elementary School, RCE of Monmouth County, Neptune City Memorial Park Designs By Kim Corbo Nuccio Planning Steps Design Calculations 5. Amount of Mulch Required Size of Rain Approximate Amount Garden of Mulch 25 square feet 0.25 cubic yard 50 square feet 0.50 cubic yard 100 square feet 1.0 cubic yard 200 square feet 2.0 cubic yards Triple-shredded Hardwood with No Dye Springfield Municipal Annex Building, Union County Planning Steps Design Calculations 6. Optional Supplies Supplies may include: • River rock PVC Pipe • PVC pipe • Deer fencing • Hoses • Sprinklers River Rock Soaker Hose Springfield Municipal Annex Building, Union County Installation Steps • Remove existing grass • Excavate to the desired elevation and grade • Add soil amendments • Prepare the berm 2. Installation • Prepare the overflow • Level the lowest zone/ponding area • Plant the native plants • Apply the mulch • Water the native plants Installation Steps Remove Existing Grass Gloucester County 4-H Fairgrounds Installation Steps Excavate to the Desired Elevation and Grade Leonard Park, Morris County Gloucester County 4-H Fairgrounds Installation Steps Add Soil Amendments Gloucester County 4-H Fairgrounds Installation Steps Prepare the Berm Springfield Municipal Annex Building, Union County Leonard Park, Morris County Installation Steps Prepare the Overflow Overflow Gloucester County 4-H Fairgrounds Leonard Park, Morris County Installation Steps Level the Lowest Zone/ Ponding Area Wheaton Arts and Cultural Center, Cumberland County Installation Steps Level the Lowest Zone/ Ponding Area Installation Steps Plant the Native Plants Cut the Root Ball Ulster County, New York Installation Steps Plant the Native Plants Planting Hole Same Depth as Root Ball Ulster County, New York Hockman Farm, Winchester, Virginia Installation Steps Apply the Mulch Protect Small Plants when Mulching Ulster County, New York Installation Steps Water the Native Plants Hockman Farm, Winchester, Virginia Maintenance Steps 3. Maintenance 1. Short-Term Maintenance 2. Long-Term Maintenance Maintenance Steps Short-Term Maintenance 1. Watering Hanson House/Hanson Park Conservancy, Union County Maintenance Steps Short-Term Maintenance 2. Weeding • Some “volunteers” may become part of your rain garden, which could be a positive addition. RCE’s NJ Weed Gallery: • Weeding more often will http://www.rce.rutgers.edu/weeds limit the amount of time you will have to spend weeding in the end. • Watch for overly- competitive species. • Some weeds can be USDA PLANTS Database: aggressively spreading http://plants.usda.gov underground by rhizomes. Maintenance Steps Short-Term Maintenance