AUGUST FLOODING: WHAT WENT WRONG AND WHY
THE flooding of recent weeks has caused many people to wonder what exactly is happening in West Cork and why.
The overall consensus seems to be that outdated infrastructure, maintenance issues and the onset of climate change all combined to create last month’s widespread flood damage – but unfortunately it’s becoming all too common.
This week, we take a town-by-town look at the story so far.
BANTRY: The town suffered a serious flood event overnight on Monday 24th into Tuesday, August 25th.
The cause of the flood was intense rainfall resulting in large volumes of run-off from high ground and high flows in watercourses.
The main culvert through the town, which conveys the Mill River from the area adjacent to Bantry Library to the seafront, was overwhelmed by the volume and intensity of the rainfall, which amounted to 50.8 mm over four hours.
The culvert in this area, which measures 6ft by 12ft, surcharged – which means there was an excess of water trying to feed into it – and this resulted in significant flooding to approximately 50 properties in New Street, Main Street, Bridge Street and The Square.
It also resulted in water damage to areas of the street carriageways in these areas. An emergency structural assessment of the culvert was completed the following day to allow repairs to the road surface before streets reopened to traffic.
The Council said: ‘A detailed assessment is now underway into this flood event, involving the local authority and the other relevant agencies, including the Office of Public Works (OPW) and Irish Water.’
This will inform decisions on short-term and longer-term actions, which will feed into the development of the OPW Flood Scheme and the proposed culvert works, which are divided in three parts, from the library through Wolfe Tone Square down to the seafront.
In the past fears had been expressed that Bantry’s culvert system – which is a 200-year-old brick-built system – could collapse. However, at a special meeting of the West Cork Municipal District in Bantry this week, Cllr Danny Collins (Ind) said he was reassured that ‘the gigantic culvert system did hold – it just could not take the volume of water there on the night.’
ROSSCARBERY: There were two flood events in Rosscarbery on August 12th and 14th with up to 15 properties flooded.
The initial assessment following site inspection and meetings between Cork County Council and the OPW is that the existing channel/stream running adjacent to the N71, in the vicinity of Courthouse Cross and two culverts under the N71, ‘may be undersized and that stream/channel cleaning may be required.’
A Council spokesperson confirmed that ‘funding for upsizing of the N71 culverts, if deemed necessary, would be expected to come from Transport Infrastructure Ireland, whereas it may be possible to access OPW funding for other elements of flood relief at Rosscarbery, through their minor works programme. The OPW has already indicated that it would support this suggestion if viable.
The local authority confirmed ‘an information gathering exercise has commenced, with a detailed survey of the above drainage system through Rosscarbery.’
The R597 Rosscarbery to Glandore road remains closed due to the extensive flood damage.
SKIBBEREEN: Flooding occurred in Skibbereen on August 19th with 16 properties flooded on Bridge Street, Cork Road, Baltimore Road and upper Bridge Street.
A Council spokesperson described this as ‘an exceptional event in terms of rain intensity, which reached up to 40mm per hour at one stage on Wednesday evening.’
The Skibbereen Flood Scheme focused on preventing flooding from the main river, the Ilen, its tributaries while also taking account of tidal effects. That scheme is substantially complete and has served its purpose well.
Construction work on the collection chamber on The Cutting at Rossa Road was still ongoing when the flood event happened. The spokesperson said work on this chamber was at an advanced stage with the permanent screen due to be installed that week.
The Council and the OPW are ‘reviewing’ this flood event to ensure that the works in both The Cutting and Cork Road areas are ‘robust going forward,’ and it is expected that a construction tender process will commence in the coming weeks for the culvert and drainage works on the Cork Road, as funding support has been confirmed from OPW and TII.
BANDON: There was flooding at the Bridge Street and Brady’s Lane areas of Bandon overnight on Monday 24th into Tuesday 25th August 2020, with indications that the combined sewer network was overwhelmed by rainfall volumes.
There are two major projects underway in the town. They are the OPW Flood Scheme, which is at an advanced stage and performed well during the flood event, and the Irish Water Main Drainage Scheme.
However, a Council spokesperson said: ‘Significant sections of these are not yet complete, and a detailed analysis is currently underway, involving Cork County Council, Irish Water, the OPW and their consultants, to determine the causes of the flood, the aim being to address any issues and prevent a recurrence of this flood event.’
DUNMANWAY: Chapel Street was flooded at about 7.30am on the morning of Saturday, August 15th, followed by a second flood event the following Tuesday, August 18th at about 2am.
Three homes were damaged by the flood waters on the 15th but they escaped without further damage on the 18th.
Local Cllr Declan Hurley (Ind) is of the opinion it should never have happened.
He pointed out that the culvert under the street needs to be upgraded if it is to cope with the more extreme weather conditions being experiences.
At a special meeting of the West Cork Municipal District he also complained about the lack of maintenance, saying there was debris at the manhole entry point and ‘a tree was growing at the exit of the culvert.’