Rain Garden
Table of Contents
Introduction
These areas are designed for intermittent or continuous rain. They may be dry most of the year, only filling with rain water and run off a few times a year. They are not permanent enough for most species to use for breeding or feeding, but they do prevent run off pollution, and enhance groundwater recharge. They can also help reduce flooding, erosion, and reduce waterway nutrification which causes ocean dead zones.
It is a good idea to pick native plants who will tolerate drought or flood conditions. Generally it is best to put plants who don't mind "wet feet" at the lowest part of the rain garden, with the more drought-tolerant plants around the rim. There should be no liners of any kind since rain gardens are intended to let rainwater permeate into the soil, but there should be an overflow. Never put these within 10ft of a building's foundation, and make sure that the overflow will not negatively impact any buildings, your neighbors, or others down hill.
Rain Gardens 101
17:00 minute video explains why rain gardens are important solutions for pollution and flood control, while filling other ecological services such as providing pollinator habitat.
This video offers helpful visuals and many tips for how to create a rain garden, vs what to avoid.
Types of Rain Gardens
Rain Gardens 101, Part Two: Types of Rain Gardens
2:13 minute video talks about different types of rain gardens based on where they are placed to prevent run off from different sources.
Bioswales
Swales are ditches designed to help retain water, and move it to a useful location while also allowing for absorption.
Often swales just have grass, but they can also be planted intricately with many plant species including certain tree species. Doing so can boost biodiversity, and the plants can boost absorption capacity in terms of water as well as pollutants.
Curb-Cut Rain Gardens
These use inlets to allow roadside water to flow into the garden. This might involve drilling a hole or cutting away some of the curb all together.
This isn't legal in all places, so check with your local laws first, and get politicians to change the rules if this method would help your community reduce flooding were it allowed.
Ditch-Side
These are placed right before ditches to help catch sediment from a property or roadway and before it impacts local waterways.
Down-Spout-Fed
These are fed by downspouts, and should be placed at least 10ft away from your foundation to prevent damage to the building.
Drainpipe Rain Garden
If your garden is too small for a regular rain garden (or perhaps you have an alleyway or street facing downspout with no space to dig) then creating a mini container garden to host wetland plants is the solution you need!
These compact gardens can absorb and clean water before allowing it to run off. They can boost biodiversity, and add a natural looking point of interest to an otherwise ugly or boring part of your building.
These can be build right up against your wall, without risking the structure of your foundation, and only need occasional maintenance to remove and replace dead plants, or trim back any that have become overgrown.
4:45 minute video "Do you wish you had a pond, but don’t have the space? At WWT we have large wetland reserves, but it’s not only the large wetlands that have value for wildlife.
Here’s a great idea to turn your drainpipe into a mini pond and floodplain with built in water supply – you’ll have your very own wetland reserve that will attract wildlife, save water and look fantastic. And unlike a large wildlife pond, it’s virtually maintenance free. In this video we’ll walk you through step by step how to create your own mini wetland.
Full instructions and more hints and tips from our experts can be found on WWT’s website"
Path-Side Rain Gardens
These are dug to be slightly lower than the level of a path, patio, or roadway, allowing water to easily flow in, and making the pathway more useable even during rainfall.
Xeriscapes
Xeriscapes are known as drought resistant gardens for hot and dry climates, but they can be implemented anywhere rain is scarce. People forget that even these places can sometimes get overabundant rain, and that there are still going to be some native plants what appreciate that extra rain.
If you live in one of these fickle climates, then consider incorporating a rain garden into or near your xeriscape. Xeriscape plants enjoy higher, drier soil, while your raingarden plants can often stand some swings between dry and wet roots. If your land is on the flatter side, consider using your excavated dirt to build some higher, and drier flower beds for your dry-soil-loving plants.
Benefits of Raingardens
Biodiversity
Plants in a rain garden can provide nectar, seeds, and tasty leaves for wildlife, as well as nesting materials.
Temporary ponds are ideal for amphibians who need fish-free spaces to breed and lay eggs.
Carbon Capture
Plants and animals help sequester carbon. Any time you grow a garden, you are helping to reduce local emissions.
Runoff Capture
Urban areas can produce 20 times more run off than natural spaces.
Urban run off is often full of pollutants which harm our waterways and oceans.
Urban runoff makes flooding worse. Our rain gardens can help protect our own properties, by helping rain sink into the ground slowly. This prevents water from building up quickly and flooding any of our neighbors downhill.
Temperature Control
The plants used in any garden can help reduce urban heat islands, and in the winter, they can help reduce the effect of cold winds.
Where to Place Rain Gardens
Farms
Farms can produce massive amounts of run off (after all they use more land than any other human activity), so planting riparian borders along waterways and planting rain gardens in strategic places can help reduce their impact naturally.
Communities
Schools
Children benefit greatly from having plants and wildlife around. They can be great educational tools, while making a schoolyard's temperature more comfortable year-round.
Rain gardens can be placed strategically to reduce flooding, keeping more of the outside area available for play time. The plants also help reduce pollution, which negatively affects IO and test scores as well as other developmental markers.
Gardens & Parks
Rain gardens can do a lot of work in a fairly small space. If your garden or local park often gets flooded by heavy rains, then digging and planting a rain garden may help solve a few problems at once. It may help prevent flooding all together, while allowing you to grow more water-thirsty plants than you'd otherwise be able to support as more of us face water-use restrictions.
Guides
Be aware that the plant species suggestions may not be appropriate for your area. Always verify that you are planting natives, and try to avoid invasive species.
Raingarden Size
Measure the surface area of the roof or driveway that will be feeding the raingarden. Divide this area by 4. This is roughly the appropriate area for the raingarden.
Clean Runoff Action Guide "is a resource for people who want to create landscapes that are good at improving flood and drought resilience and water quality in our lakes, rivers and streams, while providing many other benefits, such as pollinator habitat. The guide provides insight and inspiration into many choices available for both existing properties as well as new construction."
How to Build a Mini Drainpipe Wetland "Do you wish you had a pond, but don’t have the space? Here’s a great idea to turn your drainpipe into a mini-pond with built in water supply – you’ll have your very own wetland reserve. And it’s virtually maintenance free."
Rain gardens "are an easy and effective tool that we can use to help reduce stormwater runoff from residential properties. These gardens are strategically placed to intercept pollutant laden stormwater runoff until it can be fully absorbed into the ground. Their design allows the rain garden to serve almost as a bowl that collects water from downspouts or overland flow across a property. The water is then able to slowly infiltrate into the underlying soil. Rain gardens can come in all different shapes and sizes but are best when planted with native plants that are indigenous to the Chesapeake Bay watershed. These plants require little maintenance once established, have deep roots that soak up lots of water, provide food and habitat to wildlife, and are beautiful.
Many localities that currently have a stormwater utility fee offer a monetary credit for the correct installation and maintenance of a rain garden. For more information on how to receive this credit please contact your locality."
4:41 minute video "This video created in partnership with Winona County will walk you through the actions needed to properly maintain a rain garden from installation through year three and beyond!"
This video explains the steps needed right after planting, then periodically for years after.
North America
Canada
Alberta Clean Runoff Action Guide: Rain Gardens (PDF) "Holding back and soaking in runoff in small, depressed planting beds allow you to passively water plants without touching a tap. They are meant to both hold and cleanse runoff. They deliver a similar range of environmental benefits as ponds and wetlands, while avoiding the challenges of standing water."
USA
EPA: Soak Up the Rain: Rain Gardens includes general resources, as well as some specific to certain US states.
Considerations
Resources
Use the Natives button to find native plant species for your location.
North America
USA
Resources for Rain Gardens "Stewardship Partners and Washington State University work with numerous partners all over the state to increase education and outreach around rain gardens and clean water solutions. We’re all working together to reach our goal of 12,000 Rain Gardens for Puget Sound. Join us and be a part of this exciting campaign."
Texas
Partial Rain Garden Plant List (PDF) scroll down to bottom for list. Not all are native, so remember to cross check with your local native plant species guides.
Tools & Apps
Bee Score: Flower Finder "Select the flowers you have in your garden, then hit continue to find out your current bee kind score. If you’re not sure exactly which plants you have, try clicking the filters on and off to help identify the bee-friendly flowers in your garden." This is hosted by and for UK residents, so you won't get a bonus for "native species" if you live outside the UK, and might see your local natives listed as "non-native" or get an "invasive penalty" even if those plants are fine where you live, but this is still a fun and educational resource.
Greener LAND "This tool helps you decide which landscape interventions are best suited towards landscape restoration for the landscape you operate in. Start by selecting the characteristics of your landscape on your left." Some of the methods listed here can help you passively divert rain water to a specific point, and help absorb overflow before it becomes problematic run off.
Rain Garden Calculator (inches and gallons) "these are guidelines, not rules! Each garden site and individual circumstances are different. If your yard or budget can not accommodate the garden size recommended, consider limiting the amount of rooftop directed to the garden or installing multiple smaller gardens. No matter what size garden you put in, something is better than nothing!"
Europe
UK
Bee Score: Flower Finder "Select the flowers you have in your garden, then hit continue to find out your current bee kind score. If you’re not sure exactly which plants you have, try clicking the filters on and off to help identify the bee-friendly flowers in your garden." This is hosted by and for UK residents, so you won't get a bonus for "native species" if you live outside the UK, and might see your local natives listed as "non-native" or get an "invasive penalty" even if those plants are fine where you live, but this is still a fun and educational resource.
North America
USA
Minnesota
South Carolina
South Carolina Rain Garden Tracker "No matter how big or small, or if your rain garden is at a home, school or business, we would love to hear about it! Use the Rain Garden Tracker to showcase your rain garden, and receive a thank you rain gauge in the mail."
Organizations
North America
Canada
Pollinator Partnership Canada " is a registered charity dedicated to the protection and promotion of pollinators and their ecosystems through conservation, education, and research."
USA
Wild Ones "promotes native landscapes through education, advocacy, and collaborative action."
Arkansas
Mississippi Watershed Management Organization "works to protect and improve water quality, habitat and natural resources in an urban watershed that drains directly into the Mississippi River. We are a joint-powers local government unit and one of approximately three dozen watershed organizations in the Twin Cities metropolitan area."
California
The Bay Foundation (TBF) "is dedicated to improving water quality and increasing local water resources through action and community education with easy techniques such as rainwater harvesting and rain gardens. Rainwater harvesting improves water quality and increases local water resources by capturing, storing, and/or infiltrating rainwater directly on one’s property. Water may be stored in rain barrels or larger containers (cisterns) to be used during the dry season. Rain gardens receive water from barrels, roofs or other structures and allow the water to flow into and over the soil, watering plants and letting the water soak into the ground. This diverts water from flowing into the Bay, reduces pollution and reduces water use for irrigation."
Carolina
The Carolina Rain Garden Initiative "provides tools and resources to assist with the installation of rain gardens in diverse settings such as yards, schoolyards, community centers and more."
Colorado
Colorado Stormwater Center "provides education, training and research opportunities with the goal of maintaining and improving the health of lakes, rivers and streams through proper stormwater management."
Illinois
Mississippi Watershed Management Organization "works to protect and improve water quality, habitat and natural resources in an urban watershed that drains directly into the Mississippi River. We are a joint-powers local government unit and one of approximately three dozen watershed organizations in the Twin Cities metropolitan area."
The Rain Garden Network "was started in 2003 with the intention of bringing simple, proven and inexpensive solutions for local stormwater issues to individuals, homeowners, groups, organizations and municipalities."
Minnesota
Blue Thumb—Planting for Clean Water® "is a network of clean water and native plant stewards creating change to bridge the gap between knowledge and action by offering resources and programs to Minnesotan residents."
Mississippi Watershed Management Organization "works to protect and improve water quality, habitat and natural resources in an urban watershed that drains directly into the Mississippi River. We are a joint-powers local government unit and one of approximately three dozen watershed organizations in the Twin Cities metropolitan area."
Mississippi
Mississippi Watershed Management Organization "works to protect and improve water quality, habitat and natural resources in an urban watershed that drains directly into the Mississippi River. We are a joint-powers local government unit and one of approximately three dozen watershed organizations in the Twin Cities metropolitan area."
Ohio
Groundway Foundation "We connect people, businesses, and communities through local groundwater education and action, making us all part of the solution for clean, sustainable, groundwater."
Oklahoma
Mississippi Watershed Management Organization "works to protect and improve water quality, habitat and natural resources in an urban watershed that drains directly into the Mississippi River. We are a joint-powers local government unit and one of approximately three dozen watershed organizations in the Twin Cities metropolitan area."
Pennsylvania
Three Rivers Rain Garden Alliance "a partnership of non-profit organizations, corporations, educational institutions, and government agencies."
Tredyffrin Rain Gardens "is a program started in 2021 by the Tredyffrin Environmental Advisory Council and the TE Green Team to take action on stormwater and water pollution in our Township. This volunteer-led group has installed an educational rain garden at the Tredyffrin Public Library and launched the residential rain garden program in 2022."
Texas
The Greater Edwards Aquifer Alliance (GEAA) "is a 501(c)(3) nonprofit organization that promotes effective broad-based advocacy for protection and preservation of the Edwards and Trinity aquifers, their springs, watersheds, and the Texas Hill Country that sustains them.
The Edwards Aquifer is the source of the largest springs in Texas and the sole source of drinking water for more than 2 million Central Texas residents."
Washington
12,000 Rain Gardens of Puget Sound "Join your neighbors cleaning up Puget Sound!"
Wisconsin
Mississippi Watershed Management Organization "works to protect and improve water quality, habitat and natural resources in an urban watershed that drains directly into the Mississippi River. We are a joint-powers local government unit and one of approximately three dozen watershed organizations in the Twin Cities metropolitan area."
Maps
International
Butterfly Conservation: Wild Spaces: Put Your Wild Space on the Map "Our interactive map shows the number and types of Wild Space near you. When you sign up in the UK, your Wild Space will also appear on the map so you can show everyone that you're taking action and encourage others to get involved too."
Europe
UK
Butterfly Conservation: Wild Spaces: Put Your Wild Space on the Map "Our interactive map shows the number and types of Wild Space near you. When you sign up in the UK, your Wild Space will also appear on the map so you can show everyone that you're taking action and encourage others to get involved too."
North America
USA
South Carolina Rain Garden Tracker "No matter how big or small, or if your rain garden is at a home, school or business, we would love to hear about it! Use the Rain Garden Tracker to showcase your rain garden, and receive a thank you rain gauge in the mail."
Stormwater Management and Restoration Tracking (SMART) Tool (Interactive) Tool tracks storm water management practices in the Chesapeake Bay Watershed which spans, Delaware, New York, Pennsylvania, Virginia, and West Virginia
Grants & Funding
Europe
UK
National award schemes There are a number of key organisations offering grants and advice to community based projects e.g.
Big Lottery Fund "Groups can apply to us for funding under £20,000, or over £20,001, depending on what they want to do."
Heritage Fund "We fund projects of all sizes that connect people and communities to the UK’s heritage."
Grow Wild UK "Bringing people together to value and enjoy wildflowers and fungi"
North America
USA
California
Los Angeles Department of Water and Power: Turf Replacement Program "Take advantage of LADWP’s most popular water conservation program. Transform your lawn and create a sustainable landscape that includes:
California Friendly® plants, including native species, appropriate for the Los Angeles climate
Mulch and other groundcover to help retain moisture in the soil
A rain capturing feature like a rain garden, rain barrel, cistern, infiltration trench, or vegetated swale
Drip irrigation (as needed)
A sustainable landscape will not only help you save on your water bill by reducing your water use. You will also help recharge the groundwater, reduce urban runoff and enhance wildlife habitat—overall benefiting yourself and the Los Angeles watershed."
Minnesota
Stewardship Fund Grants "support public efforts to manage stormwater, control pollution, and improve water quality and habitat."
Oceana
Australia
Western Australia
Native Plant Subsidy "Native plants provide natural food sources and shelter for native animals, are water wise and can help cool your home naturally. To help you create a waterwise garden, the City of Cockburn offers native plant subsidies to both residents and schools."
The Sustainability Grants Program (in the City of Cockburn) "offers funding for projects related to six sustainability themes. Open to small businesses, schools, not-for-profits, and collective households, successful applicants can receive up to $4,000 for their project."