Transcript Rain Garden Powerpoint - Water Resources Education Network

Rain Gardens
for Clean Streams
Did you know?
Up to 70% of pollution in streams,
rivers and lakes comes from storm
water runoff.
Planting a Rain Garden…
• reduces the amount of storm water entering
storm drains
• helps reduce the amount of flooding by
keeping water contained so that it can drain
slowly over a period of time
• allows soil to filter out pollutants and reduce
the amount of nonpoint source pollution
entering our streams
Nonpoint Source Pollution (NPS)
is caused by many reasons.
Excess fertilizers, herbicides, and
insecticides from agricultural
lands and residential areas
Oil, grease, and toxic
chemicals
from
urban runoff and energy
production
Sediment from improperly managed
construction sites,
crop and forest lands,
and eroding stream banks
Salt from irrigation practices
and acid drainage from
abandoned mines
Bacteria and nutrients from
livestock,
pet wastes,
and
faulty septic systems
Rain and snow melt pick up these natural
and human-made pollutants, finally
depositing them into lakes, rivers,
wetlands, coastal waters, and even our
underground sources of drinking water
Impervious surfaces (ones that do not allow water
to percolate or drain through soil such as
buildings, parking lots, etc) contribute runoff water
and increase the amount of pollutants in runoff.
Rain Garden
A garden designed specifically to
improve water quality.
Rain Gardens allow approximately 30%
more water to soak into the ground.
Is a rain garden hard to install ?
During
During
After planting
After one season
Determine the location
Near the house to catch only roof
run off or out on the lawn to
catch water from the lawn and
roof
Location
• A gentle slope (no more than 10%)
– Remember that the garden needs to be dug into a
bowl shape and the greater the slope the deeper the
bowl that will need to be created
• At least 10 feet from your foundation
• Near a downspout or where water naturally
•
drains
Away from areas where water already ponds as
there will be little infiltration in this area
Planning stage
• Estimate the area which will drain into
your garden (roof and/or lawn)
• Determine the type of soil (sand or clay)
• Gardens planted in sandy soil should be
20-30 % the size of the drain area
• Gardens planted in clay soil should be
55-60% of the drain area
Example
Dylan’s house is 50 feet by 40 feet so the roof area is 2000
sq ft. (50 x 40 = 2000)
He has two downspouts and will plant a rain garden in the
back yard which will collect water from approximately
half of the roof area or 1000 sq ft.
His soil is mostly clay so the size of the rain garden should
be approximately 550 sq ft. (1000 x .55 = 550)
Remember that a rain garden
of any size will help to control
storm water runoff
Building the Rain Garden
• Be sure you check with your utility company
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before attempting to dig in your yard.
Lay out the garden with a garden hose or
landscaper’s spray paint.
Start digging on the uphill side of the garden
Remember that you will be moving soil from the
uphill to the downhill side of the garden to
create a berm and the bowl shape of the rain
garden
Creating the berm
• The berm will be the highest on the downhill
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•
•
side of the rain garden
The berm will gradually decrease as you go up
the sides of the rain garden
After shaping the berm be sure to stomp it down
so that it is well compacted
Cover the berm with compost/mulch or plant
grass or a dry tolerant native plant to control
erosion on the berm
Planting the garden
• Consider the height, color, moisture
tolerance and bloom time of plant material
• Plant in groups of 3, 5 or 7 of the same
variety
• Add rocks, boulders or other ornamental
features to add interest
• Water at least once a week until plants are
established
Maintaining the garden
• Weed out any invasive or non native
plants until natives are established
• Stems and seed heads can be left to stand
for winter interest and to attract birds and
other wildlife to the garden
• As spring approaches cut back all standing
growth and compost or discard
• Occasionally the plants should be divided
Municipal Site
During
After
During and after
During and after
Before and
After
Why plant a rain garden ?
• To prevent flooding and excess storm
water damage
• To limit the amount of erosion and cut
down on sediment entering our waterways
• To filter out and limit the amount of
pollutants reaching our waterways
• To provide habitat for wildlife
Rain Gardens for Clean Streams
Financial and other support for this project is provided by the
Pennsylvania Association of Conservation Districts, Inc. through a grant
with the U.S. Environmental Protection Agency’s Section 319 Program.
The mission of the Bucks County Conservation District is to provide for the
wise use, management and development of the county’s soil, water and related
natural resources. This is accomplished with the cooperation of public agencies,
private groups and individuals
For more information:
Mary Ellen Noonan
Environmental Educator
Bucks County Conservation District
1456 Ferry Road, Suite 704
Doylestown, PA 18901
215.345.7577
www.bucksccd.org