Nature-based measures yield positive flood results, Mayo meeting hears

A nature-based approach to mitigate flooding can yield positive results, councillors in the Westport-Belmullet Municipal District have heard.

The Carrowniskey catchment in Louisburgh is one area of study and it's hoped to have possible solutions to be tested next year.

An insightful presentation on nature-based solutions to flooding was given by Professor Mary Bourke of the Department of Geography in Trinity College Dublin, with input too from other experts.

But there was clear feedback to the meeting from local councillors Chris Maxwell and Johnny O'Malley on one action they want to happen to address flooding in their areas: clear the rivers of vegetation, with bushes growing from one bank to another.

A whole of catchment approach is needed to mitigate flooding, Prof. Bourke explained. What happens upstream will address impacts further downstream in urban areas.

This includes slowing water existing the higher catchment with works such as peatland restoration, drainage management, 'leaky drains which slow flow, afforestation with native and varied species, reconnecting rivers to their own flood plains so they are more effective to temporarily store water for a few hours during flooding, or constructing farm ponds, alongside hard engineering solutions in areas affected by flooding.

Studies have shown that a variety of interventions in agricultural landscapes can benefit downstream communities experiencing water quality and flooding problems. There needs to be a focus on upstream and managing the flood before it reaches towns and villages.

Councillor Maxwell's concern was that rivers are 'choked to the gills' with trees, soil and silt, and a conversation needs to be had with farmers. They want the rivers opened up and cleaned from the sea in, as they were in the past.

Councillor O'Malley said on his local Mayour River, people used to fish there but today the trout would not be able to get up or down it. And the same for wild ducks, who can't swim there now.

Cleaning is very important, he said, as water cannot get through with trees growing in it.

Councillor Brendan Mulroy also wondered how in the past the council and land owners cleaned drains and rivers and how we couldn't go back to that, with all the drains blocked up.

Members were told farmers involved in works that would benefit the greater society should benefit from extra payment. As custodians of the land, the consensus was they have to work with them, as councillors heard of a number of pilot project in the country working with farmers.

Cathaoirleach Councillor Peter Flynn said they had to get people around the table to come to a long-term solution, with everyone pulling together, whereas today we have the traditional approach and a more scientific one, and with a changing climate.

Locally, the Louisburgh study project is assessing the catchment and that study is due to be launched next year, when measures can be tested.

Temporary flooding of lands is something farmers understand, but where roads and homes and farm yards are impacted, it's a different scenario. Data has been given to the consultants to see if there can be interventions upstream to alleviate those flood prone areas.

It is probably the intention to apply for funding in 2026 to try implement measures and follow up with monitoring and analysis.