The Kerry Biosphere, with support from Kerry County Council and the National Parks and Wildlife Service through the Local Biodiversity Action Fund (LBAF), are delighted to host their ‘Rainwater Planter Initiative’. Our initiative aims to provide a focal point for nature-based solutions for water management, and to highlight some of the pressures on waterbodies in the reserve.

The long-term plan for our initiative is for community groups, organisations, schools, business, or individuals to install their own rainwater planter and to spread the good word about nature based solutions!

What are Nature Based Solutions for Water Management?

Nature-based Solutions (NBS) work with nature, as opposed to working against it or trying to control it. The term refers actions that rely on nature to address challenges such as potential adverse impacts on water quality, and climate change. A good example of NBS is the use of rainwater planters. The planters are a simple design and concept to reduce pressures on stormwater systems.

So, What is a Rainwater Planter, and What Does it do?

Rainwater planters are a simple concept designed to reduce the pressures on stormwater systems. The planters are sited adjacent to a downpipe which is diverted into the planter. The planter therefore collects the stormwater from the roof.

The stormwater diverted into the planter settles in the planter, instead of flowing directly down the drain. The planter itself is typically 45cm high and constructed from treated timber. The shape of the planter is up the discretion of the owner, though oblong shaped examples are most common. The planter is lined with tarpaulin to help preserve the timber’s function and prevent rot.

The lined planter is filled with layers of sand, gravel, and finally topsoil, these layers will help to filter the water. The planter can be planted with a host of suitable, preferably native plants. Good, native plants that can be used include Ragged Robin, Yellow Flag Iris, and Water Mint. The plants used must be robust and tolerant of shade, very wet conditions, and periods of dry weather. The planter is also fitted with an overflow pipe in the event of the planter being overcome with stormwater. The overflow pipe flows directly into the drain.

The finished product will also provide a food source for pollinators such as bees, butterflies, and hoverflies. When in full bloom, the planter will also be an attractive feature, providing colour and character.

Can I Install a Planter?

Yes! The rainwater planters are simple to design and construct. The size of the planter will depend on the area of the roof that is serviced, and will be dependent on the number of downpipes servicing the roof. The likely heaviest rainfall to fall on the roof is also considered and a few basic calculations will determine the size of the planter. The planter’s size will be reflected by the volume of water that we expect the planter to hold.

Are They Very Expensive?

Generally speaking, no, the planters are not very expensive. If perhaps, you decide to commission a tradesperson to design, construct, and install the planter, then the bills could add up quickly. If, however, you design and construct the planter yourself, costs can be easily managed. Cost will also be affected by the size of your planter.

Our Rainwater Planter Initiative will serve as a ‘Pilot’ project, and the Biosphere team will be happy to share our findings during the process, including what worked well, and potential pitfalls to look out for. We can also comment on the costs of constructing and maintaining the planters, although material costs will most likely keep rising.

Where can I Learn More?

The Kerry Biosphere was delighted to host a webinar with author and company director (FH Wetland Systems Ltd.), Mr Féidhlim Harty. Féidhlim has been working in the area of NBS since 1996 and is an expert in the field. Missed the webinar? No problem, the Kerry Biosphere YouTube channel will have the webinar readily available, once final edits have been completed!

Furthermore, we will be hosting in-person workshops with Féidhlim to further support our initiative. Keep an eye on our social media pages, and the Kerry Biosphere website www.kerrybiosphere.ie for dates and times of our workshops.

Is That Everything?

No! We have four ‘host sites’ chosen to facilitate our planters. All the sites are located in the Killarney region. As pilot sites, we will be able to report on the progress, success, failure, or anything in-between.

Dublin City Council have prepared a very good, and easily read document for how to design and build your own rainwater planter:

https://www.dublincity.ie/sites/default/files/2021-04/a-how-to-guide-to-rainwater-planters-english.pdf

As our Rainwater Planter Initiative progresses, we will update our website with news of how the initiative works out.

Please contact Brendan at: kerrybiosphere.skdp.net or 087 152 7746 should you have any queries.