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By allowing rainwater to inltrate rather than enter

the stormwater system, we can reduce the peak

fows during rainall events which reduces fooding

and erosion in downstream creeks and streams.

There are many benets o creating a rain garden.

Rain gardens can help:

• reduceoodingonneighbouringproperty

• reduceerosionincreeksandstreams

• lteroutpollutantsbeforetheyreachthe

storm drain and enter our waterways

• rechargeaquifers

• providehabitatforbenecialinsects,birds

and wildlie.

Rain gardens are landscape eatures that

are designed to collect rainwater runo

rom impervious suraces such as roos

and driveways. They are simply depressed

garden spaces that hold runo and allow it to

inltrate into the soils.

Buildinga Rain Garden

DisclaimerThis sheet contains general principlesonly and they may not be appropriate orevery property or project. Use commonsense when building your rain garden.You assume the risk and are responsibleor any modications to your property ordrainage fow, or legal compliance, and

or necessary permits and authorizations.Check with your municipality i you areunsure o regulations or requirements.

For More Inormation:CRD Hotline250.360.3030hotline@crd.bc.ca

CRD Stormwater, Harboursand Watersheds Program250.360.3256stormwater@crd.bc.cawww.crd.bc.ca/watersheds

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Choose Your Site

Contact your municipality and utility providersbeore you dig to ensure that you avoid anyunderground utilities.

Choose an area that is at least 3 metres rom any•

building, but not more than 10 metres rom yourdownspouts. Consider your neighbours whenchoosing your site.

Look or a level area with good drainage where•

water doesn’t pool.

Avoid placing the rain garden over a septic system•

or a water well.

Choose an area that runo can fow naturally.•

Assess Your Soil

Dig a small hole, about 60 cm deep. While digging,•

observe soil characteristics: i the soil is sticky andsmooth, it may have higher clay content; smoothbut not sticky, it is likely a silty soil; and i it is grittyand crumbles easily, it is a sandy soil. Soils withhigher clay or silt content will have slower rates oinltration compared to sandy soils.

Fill the hole with 20 cm o water. I the water does•

not drain within 12 hours, it is not a good locationor a rain garden.

Determine Sizing

Determine the roo and/or driveway area that will•

be draining to the rain garden.

Measure the area you have available or the rain•

garden.

Determine the path that the rain water will ollow•

to get to the rain garden – over the yard or througha rock lled ditch or pipe (ensure that you havean overfow that directs the water toward a stormdrain during large storm events).

A general rule is to size your rain garden to at least•

20% o the size o the impervious area that will beproviding water or the garden, depending on howwell your soils drain. This area should hold 70-100% o the water.

Design and Build

Determine the location o the garden, measure out•

the size and mark.

Determine the locations o the infow and overfow,•

lining with rocks i necessary to prevent erosion.

Dig 45-75 cm deep, ensuring the bottom o the rain•

garden is fat.

Beore replacing your soils, amend with compost•

to improve inltration, about 2/3 soil and 1/3compost.

Return amended soils to the garden, leaving an•

area o 15-30 cm or ponding.

Plant and Mulch

There are typically three zones to consider whenplanting your rain garden.

Zone 1 – bottom – choose plants that tolerate•

wetter conditions.

Zone 2 – sides – plants that can tolerate wet or dry•

conditions.

Zone 3 - Top edge – plants that are drought•

tolerant.

It is important to consider the amount o sun the•

plants will receive as well as maintenance needs.

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Steps To Building ARain Garden

Cross Section O A Rain Garden