How to Build a Rain Garden for Residential Yards
Presented by: David Dods URS Overland Park, Kansas
How to Build a Rain Garden for Residential Yards
1. 2. 3. 4. 5. 6. Locating the garden Testing site soils & sizing the garden Preparing the garden bed Planting zones Inlets & outlets Finishing touches
Photo: David Dods
Planting Beds Two Approaches
Using Native Soils
(Preferred)
With Engineered Soils and an Underdrain
Illustrations: Dan Shaw; Barr Engineering
Rain Garden Construction
Using Native Soils
Photos: David Dods; Rusty Schmidt
Locating the Garden
• Downspouts • Driveways • Sump pump outlets
• Drainageways • ~10 – 20 ft away from buildings
Photo: David Dods, URS
Places to Avoid
Utilities, Septic Systems
Uphill of Buildings on Slopes
Behind Structural Retaining Walls if Not Designed for Water/Drainage
Photo: David Dods
Testing Site Soils
• Inspect site soils. Dig a hole. Look for soil type, fill material, compaction
• Conduct a Percolation Test
Photo: David Dods, URS
Percolation Test
How much water soaks in over 24 hours?
Illustration: Marjorie Vigoren, City of Plymouth, MN
Source: The Blue Thumb Guide to Raingardens, by Schmidt, Shaw, & Dods
Sizing the Garden
• For residential yards, the bed depth is more important than the area • Average size: ~About 6’ x 8’ near one downspout • Fit it to your landscaping
Photograph: Rusty Schmidt
Preparing the Garden Bed
• Rototill or double-dig • Over-dig clay soils
• Amend with compost
Photos: Carla Dods;
Rusty Schmidt
Shape & Depth of the Garden
Pool Depth
Illustration: Dan Shaw, Waterdrop Innovations LLC
Minnetonka near Shady Oak Lake
Photo courtesy of Washington Conservation District
Bed is dug down
Downhill edge is raised up
Photos: Shawn Tracy; David Dods
Rain Garden Planting Zones
Edges: Dry
Sides: Average
Bottom: Moist
Illustration: Dan Shaw, Waterdrop Innovations Source: The Blue Thumb Guide to Raingardens, by Schmidt, Shaw, & Dods
Rain Gardens are not Wetlands or Water Gardens
• Designed to Infiltrate Water in 1 – 1 ½ Day
• Large plant selection • No mosquitoes
• Tolerates spring rains & summer drought
Improving Infiltration:
Its in the Roots
Turf Grass
Native Grass
Root Depths
Turf Grass: Inches
Native Grasses & Wildflowers: Feet
Photos: David Dods, URS
Re-test Infiltration Before Planting the Garden
Photograph: Rusty Schmidt
Planting: Include Cute Kids for Photos
Photo: Lynn Hinkle, Astra Communications
Mulch
Use Coarse, DoubleShredded Hardwood
Pinebark Nuggets & Cedar Chips Float
Photos: David Dods
Getting Water to the Garden
Downspout Extensions
Scupper
Rain Chain
Photos: Kurt Leuthold, Barr Engineering; Rusty Schmidt
Pipe
Creek Bed
Photos: Rusty Schmidt
Outlets
Make sure the water overflows where you want it to go during large storms
Photos: David Dods
Outlet at End of Berm
Minnetonka
near Shady Oak Lake
Outlet at End of Berm
Minnetonka
near Shady Oak Lake
Finishing Touches
Make the Garden Look Deliberate
Roy the Cat
Inlet Splash Blocks Edging
Accents
Outlet
Photo: David Dods
Borders and Edging:
Make the Garden Look Deliberate
Photos: David Dods, URS; Barr Engineering
Care & Maintenance First Growing Season
• Limit standing water while plants are small • Water during dry periods
• Pull weeds
Photograph: Rusty Schmidt, URS
Example Garden
Existing Garden Bed
Photos: Shawn Tracy
Overflow
(overland)
depression berm
Photos: Shawn Tracy
Depression
(w/ compost)
Berm (w/ erosioncontrol blanket)
Photos: Shawn Tracy
Depression
Berm
Photos: Shawn Tracy
Photos: Shawn Tracy
Questions
?
David Dods URS 8300 College Boulevard, Suite 200 Overland Park, Kansas 66210 913-344-1022
[email protected]
Photo: Washington Conservation District, Stillwater, MN