The document discusses the critical importance of freshwater, noting that only 1% is usable for humans and land animals, while stormwater runoff poses significant environmental issues due to increased impervious surfaces from development. It emphasizes the benefits of rain gardens, which help filter runoff, recharge groundwater, and reduce flooding, making them a sustainable and cost-effective solution for homeowners. The document also provides guidance on how to construct a rain garden, including soil testing, plant selection, and maintenance.

2. Did you know…?
3%

3. 66%
Sixty six percent of all freshwater is found in solid form
in ice caps & glaciers.

4. 97% salt

6. What?!?
1%
That leaves only 1% of all the Earth's water in
a form useable to humans and land animals.

7. This small amount of fresh water is found in
our lakes, rivers, streams, ponds, and in the
ground.

8. The Water Cycle

9. When it rains in a natural, undisturbed
environment about 50% of the rainwater infiltrates
into the ground, 40% evaporates or is taken up by
plants and only about 10% runs off the surface.

10. Our activities and development on land alters how
water naturally travels through the landscape. As we
develop the land, we add roads, houses, parking lots,
sidewalks, and driveways.

11. These hard surfaces are called impervious surfaces,
because water cannot pass through them as it does
through soil, so the water is forced to evaporate or
run off.

12. At 30 to 50% impervious (such as suburban areas
like Mandeville), runoff is tripled.

13. Stormwater runoff is one of the biggest problems
facing our waterways. Mandeville’s growing
population has increased the impervious
surfaces, which increases runoff and pollutants in
our lakes, rivers, streams and oceans.

14. Increased stormwater runoff leads to degraded
water quality, loss of habitat and aquatic life,
increased flooding and stream erosion.

16. Building a rain garden (or a couple of rain gardens)
in your own yard is probably the easiest and most
cost efficient thing you can do to reduce your
contribution to stormwater pollution.

17. A rain garden is a shallow, constructed depression that is
planted with deep-rooted, native plants & grasses. It is
located in your landscape to receive runoff from hard
surfaces such as a roof, a sidewalk and a driveway.

18. www.seeingthegreen.org
Rain gardens slow down the rush of water from these
hard surfaces, holds the water for a short period of
time, and allows it to naturally infiltrate into the
ground. A rain garden can be thought of as a personal
water quality system because it filters the runoff from
your roof and lawn and recharges the groundwater.

19. Rain gardens are a beautiful and colorful way for
homeowners, businesses and municipalities to help
ease stormwater problems. There is a growing trend by
municipalities and homeowners to incorporate natural
processes to help relieve flooding and pollution, and
we hope to continue that trend.

20. Because rain gardens are dug 4" to 8" deep, and in some cases 1' 2' deep, they hold larger quantities of rainwater, conserving the use
of municipal water and making their overall construction more cost
efficient than other green alternatives. Rain gardens also need less
technical experience to install and can be installed without permits
or heavy equipment.

21. By capturing rainwater from your roof, driveway and
sidewalks and diverting it into a great looking rain garden
where it can slowly soak into the ground, filter
contaminants and keep quantities of clean water from
going down the sewer system, you'll have a great looking
garden that puts water in its place.

22. Rain gardens are an excellent way to reduce the impact
of impervious surfaces and polluted runoff because
they are low-tech, inexpensive, sustainable and
esthetically beautiful, and in some areas, there may be
grants available to subsidize the minimal costs of
constructing a rain garden.

23. Rain Gardens
Filter runoff pollution
Recharge local groundwater
Conserve water
Improve water quality
Protect rivers and streams

24. Rain Gardens
Remove standing water in your
yard
Reduce mosquito breeding
Have water-cooling benefits

25. Rain Gardens
Reduce potential of flooding
Create habitat for birds &
butterflies
Survive drought seasons
Reduce garden maintenance

26. Rain Gardens
Enhance sidewalk appeal
Increase garden enjoyment
Remove excess pollutants

28. To start your own rain garden, you must first find the
best location, test your soil, determine the size, dig or
build your garden and plant your native plants.

29. • Between the source of all the water runoff and its
destination
• At least 10’ from your house or building
• At least 25’ from a septic system
• In a sunny place, if possible 

30. The soil is an important factor in your rain garden,
so it would be great to first test your soil. The soil
binds pollutants, preventing them from moving
down into groundwater supplies.

31. Soil
Type
How This Type of Soil Behaves
Sand
Will not form a ribbon of any length and has a
non-sticky, grainy feel
Sandy
Loam
Will form a ribbon less than a half-inch in
length and feels gritty
Clay
Loam
Will form a ribbon less than an inch in length
and feels smooth and only slightly sticky
Clay
Will form a ribbon longer than an inch in
length and feels smooth and sticky

32. www.abbey-associates.com

33. Once you determine the soil type, you will need to
test the infiltration rate of the soil by digging a 12
inch hole at the site and filling with water.

34. Mark the water level with a stick or ruler then observe
how long it takes the water to totally infiltrate the soil.
Soil that drains completely in 24 hours is acceptable
with minimal amendment of compost and sand. Soil
that takes longer than 24 hours must be amended with
compost or a mixture of compost and sand to make it
more porous or a new site must be chosen.

35. The next step would be to determine the path
of stormwater in your garden. Try mimicking a
rain event by using a hose in place of your
downspout. The area where water collects is
where you should plant your wet zone plants.

37. Dig up the soil in the rain garden with a shovel
to a depth of 4-6 inches and grade the area so
there is a lower catch basin.

38. Use the excess soil to create a small berm 6 to 12
inches tall on the lower side of the garden to help
catch water runoff to pool in the heart of the rain
garden. Cover this berm with the extra sod you
removed from the hole. This will create your dry
zone.

39. Native Plant Suggestions

40. Questions to Consider When
Choosing Your Plants
• Does the garden receive adequate sunlight for the
plants you select?
• Can your plants survive in times of drought or heavy
rains?
• Will the plants blend in with the existing landscaping?
• Have you planned for seasonal timing of growth so
that color and wildlife food are available year round?
• Have you thought about the height and width of fullgrown plants?
• Have you thought of what species of wildlife you
want to attract?
• Have you thought of specialized plants for each zone
of the rain garden you will have: the hydrazone,
hardiness zone, heat zone?
• Have you chosen a mixture of plants with different
form and texture—woody and perennials?

41. Once your plants have been chosen and placed according to
zone, you are ready to finish your garden. Mulch the rain garden
area after planting with a heavy hardwood mulch. Layer it two to
three inches deep to cover all the exposed soil in the garden
area. Avoid using lightweight mulches that will float or wash
away once water runoff collects and pools in the rain garden.

42. Water the garden thoroughly to remove any air pockets
in the soil from planting. Add 3 to 5 inches of irrigation
to all planted areas through the mulch.

43. …and enjoy!