Rain Gardens - Sustainable Drainage System (SuDS)

We design, install and plant sustainable drainage systems (SuDS) through Rain Gardens and SuDS Planters.

WHAT IS A RAIN GARDEN?

Rain gardens are a type of Sustainable Drainage System (SuDS) that capture rainfall before it enters the piped network and either releases it slowly into the network or allows it to infiltrate into the ground.  

They can help to improve surface water management while fulfilling a range of other functions such as amenities, pollution reduction and biodiversity enhancement.

Rain gardens take the form of a shallow depression that collects excess water and dries out after two days, thus preventing flooding. In addition to acting as a funnel, it temporarily holds the water while it soaks into the ground.

In order for rain gardens to play their full role, they must be well thought out and designed as there are many factors to consider.

Rain Gardens Benefits

  • Can absorb up to 30% more water than grass.

  • Increased planting attracts insects and birds, and creates a habitat for wildlife.

  • Flexible layout to fit into the landscape.

  • Preventing water pollution - rain gardens are capable of removing up to 90% of nutrients and chemicals and up to 80% of sediments from runoff.

  • Low maintenance garden.

  • Opportunity to create a nature garden incorporating a wide range of plants and trees.

  • Reduces erosion by slowing heavy rainfall.

  • Reducing the risk of sewer flooding during heavy rain.

  • They are visual and sensory, making them a great place for people too.


Get In Touch

If you have any questions or would like to know more about our services, please fill out the contact form below, and one of our team members will be in touch with you within 24 hours.

 

Why a rain garden?

The construction of a rain garden can be economically or environmentally motivated. They offer the possibility to manage rainwater runoff from hard surfaces after heavy rainfalls by planting attractive, low maintenance, wildlife-friendly space.

 The ability to mimic natural drainage and groundwater processes, and to treat stormwater at its source, enables sustainable drainage systems (SuDS) to be more efficient and sustainable. In addition, although it receives irregular inflows of water, it improves water quality by purifying the water before infiltrating it on site.

 
Good to know: a rain garden can act as a water purification area before the water infiltrates into a water table. This is known as natural lagooning.

Rain Garden Case Studies

Lambeth Rain Gardens

Last year, the London Borough of Lambeth rolled out an ambitious Kerbside Strategy. The strategy envisions kerbsides as hubs for accessible, active travel, improved air quality, social connections, and reduced carbon emissions.

Fentiman Road is looking better than ever, thanks to our Rain Garden SuDS, colourful planters, cosy seating areas, and bike-friendly spots in the heart of Lambeth!

Check out our case study for more details on these transformations.

Fentiman Road Rain Gardens (SuDS) in Lambeth

Royal Docks Corridor Rain Garden (SuDS)

Royal Docks Corridor

Last year, we partnered with the London Borough of Newham to successfully finish the initial phase of Rain Gardens along a breathtaking 4-mile stretch from Canning Town to Pontoon Dock.

These Rain Gardens are not just visually stunning; they also play a vital role. By introducing greenery and mitigating rainwater flooding, they're making a significant positive impact on the environment.

Explore our case about the transformative journey from Canning Town to Pontoon Dock.

Richmond Rd, Waltham Forest

Richmond Rd, Waltham Forest


Check out our Richmond Rd Pocket Park in the London Borough of Waltham Forest!

Finished last year, this park is a cool space that's great for plants and flowers. One of the most remarkable advantages of Pocket Parks is their ability to create a haven for a diverse range of plants and flowers, which, in turn, acts as a sanctuary for bees and other pollinators vital to maintaining a healthy ecosystem. Additionally, these parks play a crucial role in preventing flash flooding and safeguarding our communities during extreme weather events.

Brooke Road, Waltham Forest

School Rain Gardens

Last year, we teamed up with the fantastic kids from St Mary’s School to plant 4 Rain Gardens, covering 111 m2 with over 750 plants!

In collaboration with Thames Water, the Department for Education, the London Borough of Waltham Forest, Project Centre Ltd, and local residents, we've created a scheme to reduce flood risks in the area.

This initiative aims to protect homes, schools, and businesses.


Copper Mill Rain Garden - Waltham Forest - You can download our Rain Garden and SuDS Planter Guide by clicking on the download sign above.

Rain Garden (Suds) FAQs


How to Create a Rain Garden?

1. Choosing the right location

If possible, place the rain garden on a gentle slope. The slope should be less than 12% and need to make sure the rain garden is not located over water pipes or other underground infrastructure.

To properly locate the rain garden, first, need to know where the rainwater comes from. Gutters are one of the main sources. If one of them is connected to a larger roof area, it will carry more water to the land.

2. Test the soil for infiltration rate

Conduct a soil test to find out if the chosen site has a good enough capacity to absorb water. If the drainage is not good enough, it is possible that another location has the necessary soil characteristics

3. Determining the size of the Rain Garden

The size of the rain garden is determined by the size of the roof and other impermeable surfaces that carry water. The depth usually varies between 10 and 20cm.

4. Choosing Plants for the Rain Garden

Ideally, the rain garden is designed as an integral part of the landscape design, choosing not only its location but also its shape and the plants you plant in it. It is best to plant rain gardens with wetland plants (plants that like to live in very wet soil), native plants and sometimes aquatic plants. To find out which plants are suitable for rain garden conditions feel free to contact us.

Native plants are always recommended for rain gardens as they are well adapted to local growing conditions and support local wildlife, including birds and butterflies. A rain garden is dry most of the time. It usually holds water only during and after rain, and they drain within 12 to 48 hours.

Rain garden plants need to tolerate both wet and dry conditions so choosing plants that can survive a variety of moisture conditions is essential.

Colourful Rain Garden Planting Design

Example of a colourful rain garden planting design

Colourful Rain Garden plant suggestions:

  • Meadowsweet (Filipendula ulmaria)

  • Primrose (Primula vulgaris)

  • Penstemon (Penstemon digitalis)

  • Granny's Bonnet (Aquilegia vulgaris)

  • Yellow flag iris (Iris pseudocorus)

  • Daylily (Hemerocalis)

  • Purple loosestrife (Lythrum salicaria)

  • Bistort (Persicaria bistorta)

  • Coneflower (Echinacea pupurea)

When to build a rain garden?

The optimum time for this is when the soil is sufficiently dry enough to work with. For the best establishment of plants, early autumn to spring is advised.

What Kind of Maintenance Does a Rain Garden Require?

We use native plants, which means that the rain garden will not need pesticides or fertilizers. As the rain garden establishes itself in the first and second years, occasional watering of the plants may be necessary. Also, weeds will need to be removed and dead plants replaced. Once the rain garden plants have established themselves and grown, they will eventually out-compete the weeds. 

Our maintenance team uses electric vehicles to reduce the carbon footprint. We are proud to state that we do not use chemical pesticides, only natural alternatives that do not harm the environment.

Good to know: rain gardens have the advantage of being inexpensive and relatively easy to build.

Why Community ENGAGEMENT is Crucial when implementing SuDS?

Community engagement is crucial for successful SuDS implementation. Without proper involvement and public awareness, we risk facing backlash, potential vandalism of raingardens, and communities refusing these solutions in the future. This can jeopardize the broader goal of a widespread rollout. Rushing ahead without proper groundwork can lead to negative consequences.

Engaging communities in highway regeneration and SuDS schemes requires time, skill, and experience. It's essential to connect with communities meaningfully, allowing them to express their needs and view changes as opportunities.

SuDS can help bring communities together. This is especially the case if the community has been involved in the SuDS design process and residents have ownership of the ongoing maintenance. It is essential for the community to understand why installing rain gardens and undertaking other alternative drainage solutions is necessary and beneficial for the area. Involving the community should be considered an investment in the future success of the scheme. If the community is informed and supportive of rain gardens and their benefits, you are more likely to garner support from the councillors and other stakeholders making implementation easier.

Community Rain Garden Planting in Waltham Forest - This project was delivered in collaboration with the local residents.

We were delighted that our Coppermill Community Rain Gardens were recognised by Construction Industry Research and Information Association Ciria who specialises in SuDS as well as picking up the Global Energy Awards for our Rain Gardens in the UK.

 

What are (SuDS) Sustainable Drainage Systems?

Drainage systems can contribute to sustainable development and improve the places and spaces where we live, and work by balancing the diverse challenges and opportunities that impact urban design and community development.

Surface water management approaches that take into account water quantity (flooding), water quality (pollution), biodiversity (wildlife) and amenity are collectively known as sustainable drainage systems (SuDS).

Sustainable drainage systems have become increasingly popular in recent years, and for good reason. They mimic nature and generally manage rainfall close to where it falls. SuDS can be designed to transport (convey) surface water, and slow runoff (attenuate) before it reaches watercourses.

SuDS are drainage systems are considered beneficial to the environment, causing little or no long-term damage. They are often seen as a sequence of management practices, control structures and strategies designed to drain surface water efficiently and sustainably while minimising pollution and managing the impact on the quality of local water bodies. It tackles the wider challenges of climate change and urbanisation, by creating a long-term solution to water drainage, pollution and environmental damage.

four pillars of SuDS in CIRIA

Source: The SuDS Manual 2015, CIRIA,

This can be seen by the four pillars of SuDS as set out in CIRIA C753 – The SuDS Manual 2015. These are:

  1. Water Quantity - Controlling the quantity of runoff to support the management of flood risk and maintain and protect the natural water cycle.

  2. Water Quality - Managing the quality of the runoff to prevent pollution.

  3. Amenity - Creating and sustaining better places for people.

  4. Biodiversity - Creating and sustaining better places for nature.

How do SuDS fit into the planning process?

When you incorporate a SuDS system (or any other drainage system), it must be submitted to the local planning authority (LPA) for your project.

It is important to note that even if you are working on low flood risk sites, many local authorities now insist that developers, architects and planning consultants submit drainage and flood risk assessments for any development. These assessments should identify the impact of the site on any potential flood risk in local watercourses.

The local planning authority will manage flood risk in accordance with the guidance set out in the National Planning Policy Framework. Each LPA tends to publish its own flood risk policy as part of its local plan, which can be found in specific areas of its website.

 

Are there Other SuDS techniques?

  • Green Roofs - Green roofs consist of a layer of vegetation as part of the roof covering and can reduce or eliminate runoff from roofs.

  • Permeable Surfaces - (porous or pervious surfaces) allow water to seep into the ground to filter out pollutants and recharge the water table. They can include Grass (not subject to traffic); Reinforced grass; Gravelled areas. Possible to use permeable paving stones as a source control measure for small roads, pavements, car parks and yards. 

  • Filter strips and infiltration trenches - are gently sloping strips of land, covered with vegetation, where water running off a site can pass through, allowing some or all of the water to infiltrate. The rest often enters a swale.

  • Swales - shallow drainage channels are designed to store and/or convey runoff and remove pollutants.

  • Detention Basins (infiltration basins) are purpose built ponds and wetlands - that provide flow control through attenuation of stormwater runoff.