Research – SloWaters.eu

Where are Ireland’s Sustainable flood defences?

April 6, 2020/in Research, The Latest/by slowaters

We are looking for Natural Water Retention Measure (NWRM) case study examples across Ireland.

NWRM’s are multi-functional measures that can protect water resources and address water-related challenges by restoring or maintaining ecosystems as well as natural features and characteristics of water bodies using natural means and processes. This work is part of the EPA funded SloWaters (a Strategic LOok at natural WAter reTention mEasuRes) project and is being delivered by Trinity College Dublin, University College Cork, James Hutton Institute and Newcastle University.

One objective of the project is to scope the current level of catchment-based NWRM case studies (e.g. in peatlands, forests and agricultural area) that have been implemented or are being planned in Ireland. An example case could be a small scale project (e.g. farm level measures or river reach restoration) to full catchment restoration (e.g. large scale tree planting or peatland restoration). We are specifically looking for rural catchment-based cases and are not collating information on urban (such as a SuD scheme) or coastal case studies.

In order to do this we would like get information from you about any case studies you may have implemented or may be implementing. You may have implemented measures for flood risk management purposes or to improve water quality and ecological habitat (e.g. to meet WFD targets). Therefore many measures that currently function as NWRM may not have originally been installed for that purpose so it would be great to obtain information on these cases too. We are collecting this information through a short survey of 12 questions which can be accessed via the link below

If you have any questions on the project or survey objectives then please contact Mark Wilkinson (Mark.wilkinson@hutton.ac.uk). Our Twitter handle is @NWRM_Ire.

Survey about Ireland’s Sustainable Flood Defences – Become a part of it!
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The Cork Bund

April 1, 2020/in News, Research, The Latest/by slowaters

Building the Cork Bun

In a farmer’s field somewhere to the north of Macroom, Co. Cork, there is now a heap of soil where there was no heap before. Once it’s formed into the right shape, compacted & seeded, it is hoped that this heap will become Ireland’s first purpose-built Natural Water Retention Measure (NWRM). It will be a bund. (A bund is stone or earth formed into an embankment to hold back water).

There are other bunds in Ireland. A bund that’s about 4 meters high & 100 meters long was recently constructed as part of a huge flood defense scheme for the town of Clonakilty in West Cork. Another large-scale bund delineating a flood plain on the banks of the Blackwater is visible from the main road that skirts Fermoy in North Cork. The bund that we’re making in a field near Macroom, however, is different. Our bund is small and made only from locally occurring soil. It will not retain the whole flood, nor will it retain water for the days & weeks that the big bunds hold back. It will retain the critical portion of the flood, & only for a critical duration of about 12 hours – not long enough to inflict anoxia on the soil or reduce field productivity once waters recede.

Our Cork bund will demonstrate how small natural structures may help to retain floodwater diverted from a stream running along the field’s edge, when the stream begins to swell from winter storms or summer cloud-bursts. As the storm passes, the water will slowly drain through a little pipe at the bund’s base, and flow to back into its stream. The aim is cut the top off of the hydrograph for the storm flow & protect vulnerable settlements downstream from receiving all the storm’s runoff at once.

We, in the SloWaters project, do not want to capture all the storm flow in one field. We want water that falls during a shower, or rises up from the ground, to take a little longer to get down to the sea – or down to a town – & we want fields & forests throughout the catchment to hold on to the water: each in their own time letting it dribble down to the channels.

Currently our bund is a messy pile of soil, which was very kindly donated by the local council while they cleared silt & soil from roadsides to reduce flooding on the roads. When the big showers come in a few months, the soil that was blocking drains & causing the roads to flood will be helping to temporarily flood a farmer’s field. In time, fields throughout Ireland may be utilised for flood management.