How to Create Rain Gardens - Michigan Water Stewardship Program

advertisement

Rain Gardens

Andrea Berry

Shiawassee Conservation District

In cooperation with Michigan Department of Agriculture, Michigan Conservation Districts, MSU

Extension, USDA Natural Resources Conservation Services, AmeriCorps National Service

Program Objectives :

 Reduce risks of groundwater contamination

 Target contaminants: Pesticides and Nitrogen Fertilizers

 Help residential and agricultural clients reduce their risks

 Address other water quality contamination risks

What is a Watershed?

We all live in a watershed -- the area that drains to a common waterway, such as a stream, lake, estuary, wetland, or ultimately the ocean -- and our individual actions can directly affect it. Watersheds come in all shapes and sizes. They cross county, state, and national boundaries. No matter where you are, you're in a watershed.

Great Lakes Watersheds

Point Vs. Non-Point Pollution

 Point pollution in water comes from a single source

 ex: factory waste

 Non-point pollution does

NOT originate from a single source

 ex: polluted runoff

Stormwater Runoff

•Following a precipitation event stormwater runs off roofs, driveways, yards and roads.

•Pipes and ditches carry this water away to ditches, which then goes into local streams, rivers and lakes.

•Unlike sewage, storm runoff is not treated.

•As it flows, pollution such as oil, dirt, deicing chemicals, excess lawn fertilizers and trash are carried into our waterways.

Problems with Fertilizers in Runoff

 Nitrogen and Phosphorous fertilizers affect water quality

 Nitrogen causes overgrowth of plants

 Phosphorous causes algal blooms

 Clog waterways, reduce free oxygen, change aquatic ecosystems, ultimately

DECREASING WATER QUALITY

What is a Rain Garden?

 A shallow depression

 Planted with deep-rooted native plants

 Located to receive runoff from hard surfaces

 Slows the rush of water from hard surfaces

 Reduces pollution from runoff

Painted by Michigan artist Ruth

Zachary

Benefits of Rain Gardens

 Attractive

 Minimal maintenance

 Filters polluted runoff

 Reduces flooding

 Reduces pests

 Adds beneficial insects

 Attracts native birds and butterflies

Steps for Building a Rain Garden

1. Find a location

• At least 10 feet from your home*

• Water should infiltrate in less than 2 days

• NOT over a Septic Field

• As level a surface as possible

• Have your soil tested!

• In clays, add sand or gravel

Building a Rain Garden, cont.

2. Measure the drainage area

• Not necessary if you choose a low spot

• If not, measure runoff area: length x width of roof = square footage of drainage area multiply sq ft of drainage area by soil type figure sand=20%, loam=30-35%, clay=45-60%

An Example of Drainage Area

Example:

A roof is 10’ x 10’ = 100sqft

The soil is loamy so

100sqft x 30% (locm)= 30sqft

The garden should be in dimensions of 5’ x 6’ or

3’ x 10’ for best drainage

Building a Rain Garden, cont.

3. Create a design

• Layout on paper

• Keep it simple!

4. Choose your plants

• Native plants already adapted to EUP

• Select to bloom year round!

Native wildflower lists and dealers: www.wildflowersmich.org

www.chicago.wilderness.org/wildchi/la ndscape/index.cfm

www.raingardens.org

Michigan Native Plants List especially for rain gardens

Rain Garden Plants

Categories of Plants:

Native Trees

Native Shrubs

Grasses & Sedges

Wildflowers

Invasive – species to

AVOID!

Remember to Consider:

Wet to Moist Conditions

Moist to Dry Conditions

Building a Rain Garden, cont.

5. Layout the design on the ground

• Know your soil type

• Contact MISSDIG for utility lines first

• 1-800-482-7171

6. Get ready to dig!

• 5-7 inches deep

• Slope edges slightly

• Level bottom

Building a Rain Garden, cont.

7. Prepare the soil

• For clay soils add sand or gravel to improve drainage

8. Now the fun part – Planting!

• Plant 1 to 2 feet apart

• Native deep-rooted perennials, annuals, shrubs

• Trees are not recommended*

Building a Rain Garden, cont.

7. Mulch will help keep moisture in & weeds

OUT!

8. Water and arrange Downspouts

• Water every other day for the first months

• Downspouts with a 1-2’ grass buffer

Mosquitoes?

NO PROBLEM!

 Require 10-14 days to develop fully

 Rain gardens infiltrate water in 24 hours or less

 RG’s attract dragonflies, which feast on mosquitoes!

Some Examples

Source www.raingardennetwork.com

Grand Rapids, MI

Source: Rain Gardens of Western Michigan

Marywood Prairie, Grand Rapids, MI

Before After

Source: www.raingarden.org

Rain Gardens of Western Michigan

Grand Rapids, MI

Source: Rain Gardens of Western Michigan

Kentwood, MI

Before

Source: Rain Gardens of Western Michigan

Kentwood, MI

After

Front yard

Source: Rain Gardens of Western Michigan

Back yard

Cedarville School Rain Garden

Project

Cedarville School Rain Garden

Project

Cedarville School Rain Garden

Project

Cedarville School Rain Garden

Project

Cedarville School Rain Garden

Project

Sault Ste. Marie Rain Garden

 Keep the St. Mary’s River CLEAN!!

 Volunteer hours for Master Gardeners

 Site to be determined

 Possibly Sault Middle/High School

 Downtown

 LSSU

 Any suggestions?

Source: www.saultstemarie.com

Credits

Rain Gardens: A how-to manual for homeowners www.raingardens.org

www.raingardennetwork.com

www.ga.water.usgs.gov

www.cmhc-schl.gc.ca

Prepared by Andrea Berry,

Shiawassee Conservation District andrea.berry@mi.nacdnet.net

Questions?

Download