RAIN GARDENS Discovery Initiative Bill Sciarappa, Ph.D. Vivian Quinn, Program Assistant
Dec 15, 2015
Development & imperviousness reduces the natural capacity of soil & vegetation to infiltrate and take up rainfall
PROBLEMS & POLLUTANTS Flooding Erosion Increased Sediment Beach Closures Non-point Pollution
Gas and oil
Bacteria-pet waste
Eroded soil
Road salt
Litter
Pesticides
Fertilizers
Stormwater runs over streets, parking lots & lawns & washes into streams, lakes & rivers
Polluted Stormwater
• Sedimentation Smothers aquatic life• Nitrogen ammonia kills fish• Phosphorus fertilizers Algae blooms• Salt & petrochemical contamination mortality• Bacterial peaks human health hazards
What is a Watershed?
The area of land that drains to a water body - We’re all connected through waterflows through our watershed. Restoring the natural buffers along our streams, lakes and ponds provides major environmental benefits to all citizens.
Engineered wetlands Infiltration basinsGrassy swalesBioretention basinsRain Barrels *RAIN GARDENS*
SOLUTION: BIORETENTION minimizes impact of stormwater
Physical water retention & biological &
chemical
Interaction between soil, vegetation & water
* No permits needed
WHAT IS A RAIN GARDEN?
A specially landscaped, shallow depression that captures & filters polluted stormwater runoff
Reduces pollution from non-point sources Conserves water Recharges underground water supply
LOCATION, LOCATION
Residential – typically 100-300 sq. ft.
Catch rainwater from roof
From driveway & sidewalk
Anyplace that will allow stormwater to be captured
Stormwater is directed into garden by pipes, swales, or curb openings
Home Gardens
Preliminary Observation Site Selection
Where it will receive runoff Area without ponding Select flat part of yard for easier
digging At least 10 ft. from foundation Not directly over septic system Not suitable where the seasonal high
water table level is less than 24"
Full or partial sunlight – first choice Check utility markouts
GETTING STARTED
PLANT SELECTIONS Select WET & DRY tolerant plants Suggest native plants
Do not require fertilization Absorb water more efficiently than lawns Easier to maintain Inexpensive
Different heights, shapes & textures Vary blooming times Sun & Shade varieties
Inkberry Holly: Ilex Glabra - midsized evergreen shrub. Prefers moist soil, but can tolerate dry. 6-8'.
SHRUBS
Cranberry Viburnum: Viburnum Trilobum - large shrub, as wide as it is tall. Bright red fruit is attractive and edible. Prefers moist, well drained soil. 6-12'
Soft Rush: Juncus Effusus - clump forming rush which usually raches about 3' . Stems are unbranched and round in cross section. To 3'.
Wild Bergamot: Monarda Fistulosa - perennial found in dry fields, thickets, and woodland borders. 2" clusters of pale pink-lilac flowers in late summer
Blue Flag: Iris versicolor - native iris of northern wetlands with blue flowers and sword shaped leaves.
PERENNIALS
Themed Rain Gardens• Bird & Butterfly • Tree + Shrub• Ornamental bark,
flowers, and berries• Deer Tolerant
Themed Rain GardensThemed Rain Gardens
PLANTING
Arrange plants according to light needs, spacing requirements & heights
Add a layer of mulch
Invite your friends!
MAINTENANCE Watering – until established Weeding - occasional
Remove sediment buildup/trash/leaves at inflow & outflow Re-vegetate & add mulch as necessary Soil Testing – every 3-5 yrs NO Fertilizing – sustains itself
Pruning Deadheading
ESTIMATED COSTS
• Average small sized homeowner rain garden – $3 to $5/sq. ft. – yourself– $10 to $12/sq. ft. - landscaper
• Average medium landscaper built rain garden – Material - $2,000– Labor - $1,500
• Average large sized municipal rain garden demonstration Total unit cost $5,000 Expected buy-in of municipality $1,500 & boro labor, volunteer help, community equipment. Possible rain garden contest for streamside living in the municipality
Think Globally – Act Locally