If we leave things as they are South Galway flooding will get worse. A feasible solution has been found that will solve the worst of the flooding problems
As part of a comprehensive 3 year analysis the unfolding scenario of South Galway flooding provides a grim outlook for South Galway. The worst flooding experience in 2015 is not the worst-case scenario- it get much worse. This article dives into the future flooding situation in South Galway and outlines light at the end of the tunnel.
In the analysis of a 1 in a 100 flood event, it is likely that South Galway will experience much more severe flooding than recent history. The M18 will flood. The N18 will flood. Gort will flood. There will be more homes flooding across the overall region. In 2015, 37 homes were flooded, in future scenarios, this rises to 50. The following scenario shows the potential flooding impact of a 1 in a 100 year flood.
The worst affected areas are Blsckrock\/Skehanna, Gort Town and Cahermore. In an extreme flood event 50 homes will flood and a further 23 would be at high risk which is <75cm to floor level.
In addition to homes flooding, there could also be 65 Non-residential properties flooding which include 20 slatted sheds/farmyards, Garages, Thoor Ballylee, Kiltartan Church and Graveyard, businesses in Gort (8)
As we have already experienced, there could be even more significant isolation within South Galway with communities like Rinrush cut off completely for over 3 months. Overall it is estimated that 175 homes and 75 non-residential properties would be cutoff. The M18 motorway would be in flood, the N18 would also be flooded so if you wanted to get from Galway to Gort, the only option would be to go via Loughrea.
The whole of South Galway would be paralyzed and common day tasks like getting kids to school, shopping, going to work, delivering feed to cattle, would be an arduous task ,not just for 1 day or so, but potentially, for months !
Many in South Galway already know this situation. In some cases a 500m, 1 minute drive to Kiltartan School was turned into the a 50km 50 minute round-trip to Loughrea. I’ve heard similar experiences with some young mothers in Cahermore clocking an additional 700km a week just to bring and collect their children from school.
In the past, some farmers had to relocate their cattle from their sheds to friends, neighbours sheds or even into Gort Mart. So, a 10 minute feeding time twice a day can become a two hour task, traveling several kilometers.
In future flooding scenarios, 49 individual sections of road would be flooded, including Crowe Street, Gort. The Kiltartan to Kinvara connection could be flooded for 99 days.
This level of isolation has a major impact on the life and soul of a community and businesses would see a catastrophic impact in the region.
This is the future reality of South Galway flooding, with Climate Chane considerations, and our committees remember the pain very well – be it a long-stay in a local hotel room for weeks, sleepless nights with the drone of pumps in the background, the alarm clock set an hour earlier to get kids ready for school, the anxiety of farmers as their livelihoods are under threat consistently for months.
Dynamics of flooding
The forensic analysis of flooding dynamics rely on statistical analysis on each of the floodplains as the complexities of the overall South Galway region arealmost impossible to gauge – its possible that the Blackrock/Skehanna flooding scenario could happen one year and Gort is OK, only to be reversed on the next flood event. In summary.
The frequent flooding scenarios that we’ve experienced in the past 3 decades will continue and get worse.
Light at the end of the Tunnel
So, yes, that was the grim reality of what South Galway will probably experience frequently in the future if things were to remain the same.
Over the next 4-5 weeks, there is a public consultation on an emerging preferred scheme and we would recommend that people engage with Ryan Hanley consultants to understand the current flooding impact and the proposed solutions to alleviate extreme flooding. All information can be found here.
Recommendations are to leave feedback or contact the project team to answer any questions you have.
The outlook of flooding in South Galway looks bleak but the proposed scheme could address this. We recommend South Galway residents, business owners, farmers to give their feedback (positive, negative, or any concerns) on the scheme as part of the public consultation process.
In October last year, high winter water levels and flood relief delays was leaving South Galway exposed to flood risk. While August and September 2019 were close to double the expected rainfall, October and November had less rainfall than normal and it looked positive that the South Galway would escape yet another winter without flooding. Some people had expressed this to me that we were coming out the far side of this and it was unlikely that we would get flooding now. Some people were more cautious reflecting back to 2014 when we had a significant spike in February 2014.
Less than 2 weeks ago,The Blackrock Turlough, Peterwell, was close to disappearing and this morning it’s less than 1m from the road between Peterswell and Skehanna. There is more to come off the mountain and there is more rain on the way.
While recent rain it not the dramatic rain downpours of 2009 and 2015, or the large flooding volumes either, its a slower creeping buildup of water levels. This latest rainfall will likely flood roads around Tierneevin (just flooded across road as I’m typing..) and Tarmon and potentially by the weekend some roads around Blackrock, Peterswell, Ballylee, and we still have unpredictable weather over the next few weeks.
We have in some ways been lucky in the past 2 weeks. While Storm Ciara packed a quick punch of rainfall, Storm Dennis hopped off us and landed with a vengeance in England where it offloaded a months rain in 48 hours.
However, even today Thursday 20th of Feb, the outlook is for Heavy rain tomorrow and Monday.
The following graph shows the water levels at Russaun, the outlet of Lough Cutra. This essentially is the level of water that flows through Gort town (and eventually into Kiltartan)
Up until 9th February, the levels had stabilized and then Storm Ciara hit which surged levels. Storm Dennis and yesterdays rainfall have kept the levels up. This level of water won’t cause any sudden flash flooding but will continue to fill up Coole, Caherglassaun and Cahermore and make South Galway more susceptible to severe flooding if we get a further ‘winter’ storm.
The key concern here is that if we got another severe storm, then we could see a similar surge as we did with Storm Ciara on top of current levels – which would likely bring several flooding to the area.
On the backdrop of this, Galway County Council is due to submit Feasibility report in the coming weeks (Last date given was Q1-2020) – which will then decide on the future and viability the South Galway Flood Relief Proposal. South Galway, now, more than ever needs solutions not more failed report or expensive studies.
We are at the ‘right’ side of the flooding season and hopefully we will make it through unscathed. We are coming very close to the time to call out our elected representatives on their commitments to finally eliminate flooding in South Galway.
We should be keeping in mind a storm of a different kind if this much needed project fails to make it through.
If this penalty application gets through in December – the Irish Government will have to pay over €4,168,000 into the ‘European Union own resources’ account and then continue to pay €10,000 per day thereafter.
In 2003, The Derrybrien Windfarm Developers (ESB – 95% owned by Irish Government) didn’t do a proper Environment Impact Analysis for their development and proceeded with development and caused a massive landslide
In 2008 : After analysis the European Courts ruled against Ireland with a court order to reassess the Environmental Impacts and put in proper mitigation in place.
In 2008, the Irish authorities informed the Commission that the wind farm operator (ESB) had agreed to provide an updated environmental impact assessment
In Jan 2018, the Court of Justice of the European Union (CJEU) issued a statement which indicated that Ireland would face fines of over €2m. The court stated that even at this late stage, a full EIA must be conducted, which must include full consultation with residents, industry and other relevant stakeholders.
In April 2019, a That leads up to last Monday when the CJEU met in Luxembourg on the case. The full contingent of Judges (15) were there to listen to Ireland’s progress since January last year – it wasn’t great and the Irish Government was harshly critizied as it had not acted to implement the earlier judgment and there was quite some disbelief that Ireland could/would not act more decisively against a 95% state owned company. (ESB)
Before we dive into the money – an interesting point to consider is that Richard Bruton Minister for Communications, Climate Action and Environment is also responsible the the ESB (well 95% responsible anyway) and obviously responsible for the Environment – so – this should have been easy as the buck stopped there. After the April 2019 Judgement, frustrated by Government in-action I compiled a set of questions that I wanted the get answers to:
What progress has been made over the past 11 year and specifically, what actual progress has made in the past year, since the EU indicated potential fines of €2Million and 12K/day thereafter?
Why does Ireland seem unprepared and unprofessional in this. (To quote an EU environment enforcement officer ” There was quite some disbelief that IE could/would not act more decisively against a 95% state owned company. ” What is causing this delay?
As its likely that we will now receive harsh fines – Who will be footing this bill? Will this be the ESB or the Irish Government?
What are the Governments plans to rectify this and when will this happen?
In order to get clarity I asked our local Fianna Fail TD, Deputy Anne Rabbitte to help get some clarification here and I asked her to frame some Parliamentary questions about this to the Minister for Communications, Climate Action and Environment. This she did and this was the response from the Ceann Comhairle
“I regret to inform you that I have to disallow the (questions) … The Minister has no official responsibilities to Dail Eireann for this matter and is a matter for the ESB which is independent in its functions.”
We are not allowed to ask questions about a potential large penalty to be imposed on the Irish Government by the European Court of Justice on an environmental infringement. We are told we have to leave it to the ESB, a company 95% owned by the Irish Government, who promised to carry out an Environmental Impact assessment over 11 years ago because it is independent in its functions.
I can see how the European Court of Justice as critical of Irish Government governance = tail wagging dog
This is only an application and the final judgement will be given in a few months time, likely be the end of the year. This application has proposed
A lump-sum fine calculated at a rate of €1000/day from the date of the Court Order to the date of final judgement
A daily penalty of €10,000/day from the date of final judgement until the matter is fully resolved.
This isn’t news (we have always known) that this was coming down the road – ESB could have avoided this – The Irish Government could have avoided this by just doing the EIA.
If we say the final judgement will be 1st December 2019. That’s exactly 4168 days since the Court Order. (3rd July 2008)
If this penalty application gets through in December – the Irish Government will have to pay over €4,168,000 into the ‘European Union own resources’ account and then continue to pay €10,000 per day thereafter.
Note : This amount is 3 times the normal amount we should be paying because of the lack of response – Ireland got the maximum multiplier factor of 3 for this.
How does this relate to flooding in South Galway?
The original EIA of the wind-farm indicated that there would be no additional drainage on the 4sq KM site on the main Slieve Aughty Peak. After the landslide happened the developers put in place a ‘Robust-Drainage‘ Scheme, which involved digging 6ft x 8ft drains from each of the 71 turbine bases . Overall, the drainage of the site was impacted by:
200 Hectares of forest was clear-felled
Over 30 km+ of drains were dug
Over 17km of roads were constructed
71 turbine bases were dug out and constructed
With no impact assessment – how knows the effect the wind-farm has on the drainage but if you now consider this picture you can see why Derrybrien, Gort and South Galway communities should be concerned.
The severe flooding in Gort in 2009 was from the Gort River which comes down from this area.
The South Galway Flood Relief Committee want the same thing as Europe here – a proper assessment on the impacts of mountain operations in this area and retrospective mitigation to ensure that potential flooding impacts from the wind-farm are mitigated in some way.
The real frustration here is that rather than than investing in flood mitigation ware are throwing away money having to pay these penalties because organizations that could be contributing to the flooding won’t do the proper assessments and the Irish Government is standing idly by as money pours down the drain – Meanwhile the South Galway Flood Relief project has a risk of not progressing because it could be deemed to be too costly
This is something that we need to get vocal about as this is our money we are wasting and our flooding solution that could be in crisis. Please share!
For more information on the Derrybrien Windfarm Saga :
Following recent public consultation and the emerging preferred scheme, it has come to light that TII (Transport Infrastructure Ireland) , also known as NRA (National Roads Authority) made some significant blunders in the motorway design and construction at Kiltartan/Raheen that may have significant impacts on flooding in the area in the future. The flooding sensitivity and unpredictability highlighted by locals and the OPW was not considered in the design of the flooding mitigation and there was a lack of future-proofing that will now pose challenges to the South Galway Flood Relief Scheme
Flooding Concerns Highlighted
Before the severe flooding in November 2009 locals David Murray and John Nolan met with the National Roads Authority (NRA but now TII) and highlighted concerns of building the M18 Motorway across a flood overflow path that happened in previous years between Kiltartan, Corker, Raheen and into Coole.
After the severe flooding in 2009, David Murray compiled a report that outlined the flooding dynamics in Kiltartan and the concerns, if the motorway was going to go ahead, to ensure properly sized and placed culverts to account for this overflow. This report include maps, videos and photos of the flooded area.
The report (referencing the New N18 (M18) outlined various concerns.
Properly sized and placed culverts would allow water to flow eliminating buildup of hazardous flooding levels. One beside Eugene Nolan’s house in Corker and an upgrade to existing culverts at Raheen. These culverts would be needed in addition to culverts on the new N18. As this route will be modified during new N18 development, it could make sense to include these modifications.
Kiltartan Flooding Report, March 2010
The report was sent to the NRA and others along with various emails and it was indicated that these would be taken into consideration by the ‘experts’ on the scheme.
The concerns have been raised in regard to building of the new N17 to ensure that this overflow can be handled with properly sized and placed flood culverts.
Kiltartan Flooding Report, March 2010
This was highlighted to the NRA in 2010 who were still designing the motorway. Additional communications also questions the flow rates used in the design but the culvert designs were deemed sufficient.
An additional report to the OPW after the several 2009 floods, highlighted the flooding situation in Kiltartan highlighted the ongoing saga of raising roads without putting in culverts. The Kiltartan-Raheen Road was raised 3-4 times since 1995 and which subsequently created a dam that kept water back in Kiltartan and contributed to flooding of Kiltartan Church. This was as indicted below.
The OPW did the analysis and looked at levels where it became very obvious on how much the road had been raised in the past. Here the red lined ‘mound’ that holds the Kiltartan-Raheen road has been raised continuously since 1995.
The recommendations in the report was to install culverts through this ‘mound’ as follows:
The key things to note here is that
The invert-level (or Base level) of the Culvert is 11.74m (Above Sea level)
The cluvert installed was too small to take subsequent flows (2015)
The OPW report concludes as follows:
It is considered absolutely essential that the design of the new motorway take into account the water dynamics at Kiltartan so as to avoid any flow restrictions. The flow to be considered while designing the motorway was determined under this report and found to be approximately 100m3/s.
Kiltartan Flooding Report January 2011
The report also recommended the following :
M18 Design Flaws
It now appears that there were significant design flaws in the motorway culvert designs. From data obtained during public consultation – The levels of the culverts installed 700m downtream in the M18 Motorway were higher than the upstream culverts on the Kiltartan-Raheen road. In fact the base (invert) level of the lowest culvert under the M18 motorway at Kiltartan is over 2 ft above the base level of the upstream Kiltartan-Corker Culvert, meaning that the water would have to rise just under 2ft way up the culvert before it would work.
Here you can see the lowest Culvert Base at 12.4 M (above sea level/OD) where as the culver based in Kiltartan-Corker is 11.74m, and Corker -Coole Culvert is 10.43m.
TII/NRA may defend themselves and say that the motorway culverts were aligned with the topography of the land in question but this doesn’t really hold. Why were the culverts not aligned (or below) the level of the overflow?
There was already a land profiling works done after 2009 flow
In 2015, it was again obvious that the culverts and profiling weren’t working as water was backing up
Flooding in South Galway has been deteriorating and unpredictable. There were no provisions made about future scenarios
It was highlighted that Kiltartan was a ‘Pinch Point’ in the overall South Galway Flooding Dynamics
TII can claim that they were not making any additional changes to the hydrology of the area but what there were doing was constructing a substantial obstacle for any future works. If they were worried about unpredictable and changing hydrology, surely the topology of the land itself would have restricted flows and they could have installed culverts at a lower level to at least align with the Kiltartan-Corker culvert (which was at 11.74m) .
It is clear that the M18 Culverts at Raheen were not designed with consideration of local concern, OPW concerns and the future of the area in mind
Keeping ‘things as they were’ in an area where the flooding situation has been deteriorating for the past 4 decades with full knowledge of the longevity and immutability of a Motorway is poor reflection of road engineering and TII and will now likely incur a significant cost.
South Galway Flood Relief Scheme Recommendations
The emerging preferred South Galway Flood Relief Scheme Feasibility has indicated that the M18 Motorway will need a new large culvert to take something like 40m3 of flow. The report defines:
Augmenting the culvert capacity under the M18, e.g. installing a new 45m long 7.5m x 2.5m culvert complete with headwalls and with invert of 11.1mOD (invert designed to be lowered if necessary).
So there it is, in black and white, the base level of the culverts will be 11.1m (or lower) and will need to be 7.5m wide and 2.5m high. In the current scheme of culverts, it will look like this:
What is the impact of doing nothing:
According to the feasibility study, if the existing M18 culvert capacity is not augmented and only the flood relief channel works undertaken, the 1:100 flood levels in Kiltartan and Corker would rise over 2 ft. over the proposed targets and scenario and properties at properties at Corker and Kiltartan would be under significant flood threat. This is a scenario that must be avoided.
What is happening now?
So is this work part of the South Galway Flood Relief Scheme? According to the feasibility report, this is ‘Under Review’ but the onus and cost of adding this new culvert must come under responsibility of TII. They commissioned the design, they were notified by local people and OPW about the flooding risk and they built their culverts at a level that is too high to allow further flood mitigation. The installation of these new culverts at the right level needs to be done and paid for by TII and must not be allowed to threaten the delicate cost-benefit ratio and the viability of this scheme.
Flooding in Kiltartan has been exacerbated in the past. Roads were installed across overflow routes without proper consideration of volume and flooding levels and churches and land flooded. Once again Kiltartan is in the same situation as now a motorway has been installed without proper consideration of volume and flooding levels. TII now has a responsibility to fix this flawed design.
Given the recent easing of Covid restrictions, the South Galway / Gort Lowlands project team are now in a position to progress the additional phase of public consultation from next week, until Friday 25th June.
The original public consultation phase deadline was asked to be extended due to concerns that the potentially impacted landowners of the emerging proposed scheme needed to meet with consultants on the land to fully understand the proposals.
“While an immense amount of work and a lot of technical data was produced for the proposals, the expectation that many landowners would be able to gain a sufficient understanding from maps and complex hydrology tables and terms was too much to ask”, said David Murray, chair of South Galway Flood Relief Committee. “We got a clear demand from landowners to meet people on the ground to be able to understand how this proposed scheme would work on their land.”.
The meetings are being arranged to facilitate land owners that have particular issues with the proposals and also land owners that may not have access to, or fully understand, the information that has been published during this consultation.
“It is not intended to meet with every land owner that will be effected by the scheme,” indicated Enda Gallagher, Project Lead at Galway County Council. “The vast majority of people that emailed or phoned the project team during the initial consultation phase, were fully informed and fully satisfied with the responses they received. We have already received a number of requests for site meetings.”
The site visits will be commencing the week of the 24th of May and the one month extension to the this Public Consultation phase will be on going until Friday 25th June. Members of the public can make submissions by email firstname.lastname@example.org or telephone (091)509309.
If you have any questions on this consultation /site visits then you can also use the number above.
It is important that this project has active public participation and we are encouraging people to give feedback as this is our one shot at ending this frequently occurring disaster for our South Galway Communities.
You can still give feedback using the online form, or email/phone above, or let us our your County Councillors know if you need a paper version.
In an unbelievable turn of events, the ESB has recently erected signs on the entrance to the Derrybrien Windfarm warning against the cutting of Turf on the Derrybrien Windfarm site, without any consideration of the local community.
There are about 114 plots of land within the Windfarm site boundary that many residents of Derrybrien and Killnadeema have been using for these through their lifetime for individual use as fuel.
In October 2003, a subsidiary of the ESB destabilized the peat on the Slieve Aughty mountains during the early stages of construction of the 70-turbine Derrybrien windfarm, which resulted in dislodging around half a million cubic meters of peat down the mountain. In Nov 2019, after 11 years of playing cat-and-mouse, the Court of Justice of the European Union slapped Ireland with a €5m fine and a subsequent €15,000/day fine until a retrospective environmental impact assessment and mitigation measures are put in place. As part of the expected assessment, public consultation was expected be incorporated into the process – unfortunately, the ESB has continued to pay lip-service to the mandatory process and once again is leaving local communities, literally, ‘out in the cold‘.
Last year the ESB, after a decade of ignoring the process, carried out a ‘Remedial Environmental Impact Assessment Report (EIAR)’ in which they have stated that they (GortWind Farms) “ have engaged with the general public in relation to the Derrybrien Wind Farm Project throughout the development and operation of the Project.” This engagement constituted providing a ‘plain-English’ flyer to people within 10km, putting up the required notices in August and letting people know that the EIAR had been completed – not exactly engagement – but more dictation!
In recent weeks, we have seen another example of this type of dictatorial engagement. The ESB has put up a sign ‘Warning! – Risk of Peat Instability from peat harvesting on site’. This has been a complete surprise to the local communities. With the sign, the ESB have once turned the tables on the South Galway communities, meaning that Turf-cutting contractors will be the ones liable for peat destabilization and not the ESB themselves.
Is seems that in their EIAR they have concluded that Slieve Aughty, Derrbrien is at risk of further instability due to Peat harvesting and are now issuing an official warning about this. This sign has effectively halted peat operations in the region and it has thrown uncertainty on tens of families who depend (and have always done so) on peat as their fuel.
It’s a very disturbing situation– In 2003, The ESB who literally ploughed ahead without a proper impact assessment and dug 17.5 Km of roadways, 39Km of drains, and excavated 185,000m3 of Peat siloss have now concluded, ‘retrospectively’ that the Slieve Aughty Mountain was so sensitive that even peat harvesting is a danger.
It is however the manner in which ESB approaches this that is causing big a concern in the community. There is no willingless to engage with local communities to really understand the real impacts on people.
“Within the face of all the controversy surrounding the ESB’s management of the Derrybrien windfarm, this just shows the level of belligerence that South Galway communities have to deal with,” said David Murray, Chair of the South Galway Flood Relief Committee’. “They caused the issue, they were asked to fix it but for years they refused. The Irish public has since been required to bail out them out with fines now mounting to €13 million, and growing daily and this is how the ESB continues to behave- It’s atrocious”
“The Derrybrien windfarm continues to have a big impact on the communities here but the ESB continue to blatantly ignore this and with this latest statement, they are exacerbating it”, said Martin Collins, Derrybrien. “We cannot accept and will not accept the self-serving assertion that there are no significant adverse impacts form the windfarm development. Even the erection of this sign has now had a direct impact on people here who now cannot get their turf cut”
The EIAR has stated that warning signs will be erected at site to raise awareness and highlight the recommended mitigation measures and communication will be established between the plot owners, turf cutting contractors and the windfarm site manager of Gort Wind Farms. Currently, all we can deduce is that right at the start of cutting season these signs have been erected but communications have been sparse to non-existent. There have been no ‘recommended mitigation measures’ highlighted as such.
What has been missing in the EIAR is the impact that this would have on the community – what about the people depending on being able to cut turf.
Worse still is that the ESB are trying to turn the tables as the EIAR even states that “In the worst case scenario, a large scale peat slide related to the impact of mechanical peat extraction in the turbary (turf) plots could impact the infrastructure for the wind farm”
So the turf cutters can now be held liable for instability including any damage to the windfarm itself.
Flood Risk Assessment
Murray indicated that the flooding risk assessment was also significantly flawed. One of the core principals of these environmental impacts assessments is that they need to take into consideration the cumulative effects of other projects or operations. The EIAR however contained a statement, “It should be noted that for the purposes of this assessment, only the impact of felling associated with the wind farm project was considered and any other felling carried out in the area during construction and following commissioning is beyond the study scope.”
In other words, this means that as ESB should have co-ordinated with Coillte to understand previous and future forestry to get a better understanding of the impact of the windfarm would have had on the flooding risk. If they did their research they would have found out that in the few years previous to the windfarm development, there have been 987 hectares of afforestation, 1,852 hectares of clear Felling, and 1,209 hectares of Thinning, operations that would continue to have an impact through windfarm development. They didn’t do this then and based and they have refused to do it now.
By refusing to engage proactively with local communities, the ESB are shooting themselves in the foot if they want be rid of these European fines. The frustrating thing here is that they will also be shooting each and everyone of us in foot also!
A simple example is that the ESB was over reliant on OPW floodmaps to determine past flooding events and they overlooked any impacts on the Beagh area as they pronounced Gort as the main downstream area that flooded. Public consultation and engagement with the South Galway Flood Relief Committee would have highlighted this. The ESB refused to consider materials already provided by the SGFRC which indicaed this.
Bully in the playground
With their belligerent and arrogant approach, the ESB is behaving like the bully in the playground and continues to trying to trample the local community once again. Our government is acting like a demure school principal turning a blind-eye to this unacceptable treatment. The EU is the only one that is backing the local communities – It is monitoring the playground and may not like what it sees. If the EU decides that this process has not reached a satisfactory outcome then these fines will last a lot longer.
At the end, it us, the taxpayers that are paying for all of this blundering but we need to seek a resolution through our public representatives and ensure that we are protected from this situation.
The South Galway Flood Relief Scheme in currently in public consultation and looking for feedback (positive and negative!) from the community. One key aspect of the emerging Engineering Scheme flood are channels. There are 16km of channel works split into around 25 individual channels. These channels have varying widths, depths and features and this article gives some additional insight into these fundamental parts of a flood relief solution and its important for many people to understand what they.
What is a flood alleviation channel in this scheme?
In general a flood alleviation channel, is a constructed path for water to flow as a predetermined level that will help ‘channel’ waters between the key Turloughs in South Galway from mountains to sea. In general, these channels follow the existing overflows that we have seen in severe flood events, but these are designed to kick-in at lower-levels to help mitigate flooding across the region. These channels are NOT concrete structures but are in fact land that is profiled to achieve the required flow as the required depth. In fact this is what channels could look like (Artist Impression only) : (from South Galway FRS website)
What kinds of channels are we talking about?
Channel distances, widths and depths will vary from area to area, and from within the channel itself to achieve flow. While land can rise and fall a channel will maintain a downhill flow to bring water from A to B.
Some channels are 1 m wide (Tarmon) and some are 30m Wide (Caherawooneen Bypass Channel). Blackrock (15m base)
Some channels are 83m in Length and some are over 1km (Kiltartan, Caherglassuan and some 2km (Caherawooneen)
Some channels are 70cm deep, and some are 4m – the average depth is about 1.3m)
The feasibilty study give some insight into channels which is summarized be shown below. In general
Base Width/Main Width
This is the width of the base of the channel
Usually given in Average Depth and Maximum Depth
This defines the slopes of the channel e.g. 1 in 2 (every metre depth of a channel will be sloped by 2m width
A channel with a 12m base with a 1m depth and 1 in 2 slope would look like this:
A channel of 4m deep with the same 12m base would be 28m wide
The feasibilty report mentions fencing and there seems to be two types of fencing indicated.
Fencing across the channel – between properties
Fencing running alongside the channel
Fencing across the channel will happen as the channel crossed field boundaries. This fencing must ensure that the waterflow is not impeded and is commonly a galvanized type of structure as shown below:
In general it is hoped for many channels, where feasible would be ‘returned to agriculture’ – meaning that these channels may only kick in every several years (some more frequent than others) and so can be farmed in the meantime.
When a channel crosses a main road or access road then culverts are needed and with this emerging preferred scheme, many current culverts will be upgraded.
The different channels are shown in the design maps as something like this:
The path of the channel is indicated on the design schemes as shown below.
During this public consultation it is important to give your feedback on the scheme. you can do this by emailing the project team or calling them at +353 91 587116 with any queries, feedback or concerns.
As part of the public consultation process, the South Galway Flood Relief Scheme has proposed a range of measures to protect the area from extreme flood events. The majority of severe flooding happens when our Turloughs reach levels that cause homes, buildings and roads to flood. One of the key underlying strategies to manage flood events is to define Target Maximum Flood Level for each flood plains. This is a level in which homes wouldn’t flood and be given at least 75cm ‘freeboard‘ from finished floor level. The TMFL is not just about the level that saves flooding in particular floodplain, it is also a level which wouldn’t cause flooding impacts downstream and also it wouldn’t threathen SACs – so essentially it is dependent on TMFLs from other floodplains – that’s where many of the complexities lie
The next key strategy is to allow overflow from Turloughs/floodplains to ensure that levels don’t exceed the TMFL – this is generally done through Overflow channels.
The diagram below shows a Turlough with a 1:100 year flood event that floods a home. the TMFL is reduced from the peak flood event and channels are constructed to take the overflow of the water
What are the TMFL levels? These can be found on Page 14 of the feasibility report (Page 28 of PDF). The key question that people are asking is – how much will it drop the water level in my area? The table 2.2 shows the difference between the 1:100 year flood peak and the TMFL.
On average this is a difference of 1.4m and in some cases it’s 2.4m. A general observation that this is not a huge drop but from analysis, it saves homes, farms, buildinges from flooding and gives adequate freeboard – this is the basis of the proposed solution – the emerging preferred scheme.
Another way of looking at this and the relationship between Turologh 1 in 100 year flood level is as follows: The Blue is the 1:100 flood peak, the Orange is the proposed TMFL.
This diagram really underscores the proposed flood relief scheme. The channels are there to take the extreme peak of flooding, from Turlough to Turlough and save all of the homes, buildings from flooding along the way. This is not a drainage scheme because once the channels stop flowing, its down to normal Turlough drainage after that.
If we add more information here we have the following
Some things to note on this.
The blue line is the 2015/2016 flood event which is very close to the 1:100 flood event – this isn’t surprising as it was the worst that we’ve experienced to date.
The grey line is what we could expect to experience in our Turloughts very year or so.
The Yellow line is summer levels which will be the lowest water level (for Wet Turloughs like Coole, Caherglassaun) or actual land level like Blackrock (Dry Turloughs
In general, for the upland Turloughs/floodplains, the TMFL is halfway between the 1:100 year flood levels and a 1:2 year flood level (Normal) . In the lowlands, its a bit more
Why is TMFL not lower?
We are quering this at the moment because initial TMFL recommendations that were analyzed were lower than these, especially in the lowlands Kiltartan=> Caherglassaun. The response to this query is because of environmental concerns.
Why do these channels like?
The following are mock-ups of channels. In general, channels are mainly land profiling where lands will be profiled, lowered and returned back as agricultural land.
There’s lots more to analyse here and I recommend that people visit the site and book an appointment with the consultant to discuss the proposed emerging flood relief scheme
After decades of difficult times for the communities of South Galway and North Clare, a comprehensive feasibility report has been published On Monday 22nd Feb, detailing of an emerging solution for flooding in South Galway.
The key objectives of the feasibility study revolved around protecting people and their livelihoods, protecting all residential, non-residential properties and cultural heritage sites from flooding and to ensure strategic road routes and access to rural communities are at low flood risk. These objectives would need to be achieved at a cost-beneficial, environmentally sustainable and socially acceptable manner.
This feasibility report contains flood risk assessments, emerging design, environmental impact assessment, cost-benefit analysis. It easily demonstrates the enormous scale of the flooding issue in South Galway and the level of analysis and detail required to get to a feasible solution. This has been a gargantuan effort from Galway County Council, Ryan Hanley Consultants and Mott MacDonald and can be seen in the level of detail provided (even in summary form)
Future Flooding Impact
The flooding assessment was carried out on a 1:100 flood event adjusted for future climate change effects and paints a very bleak picture with impacts such as :
73 residential properties at risk of flooding/high flooding. (9 of which are in Crowe St Gort)
65 non-residential properties, including 20 slatted shed complexes, cultural heritage sites (Thoor Ballyee flooding over 3m)
175 residential properties and 46 non-residential properties, including dairy farms, are at risk of being cut-off due to prolonged flooding of all road access
19 rural communities cut-off throughout the Gort Lowlands (The community at Rinrush are at risk of being cut-off > 3months.)
49 individual sections of road including the M18 motorway at risk of flooding. The main roads route through the study area, namely the M18, R458 (old N18) and Kiltartan to Kinvara Road (L4506 and L4509) are at risk of closure for over 7, 34 and 99 days respectively.
The Limerick-Athenry Railway line is at risk of flooding at Castletown >25 days.
Significant amounts of farmland that are flooded beyond normal flood levels
Emerging Preferred Scheme
The feasibility study, completed from over 3 ½ years of complex analysis and modelling, has produced an emerging preferred scheme. There is a substantial amount of detail the feasibility report which can be downloaded here:
This scheme comprises a series of large flood alleviation channels and culverts which provide a temporary overflow pathway between floodplains and Kinvara Bay, each with a specific overflow level and capacity designed to achieve Target Maximum Flood Levels. It also includes other flood protections works including additional pumping facilities, embankment upgrades and road-raising works. Among the works, this scheme includes:
16km of channel works
303,000m3 of excavation
30 large culverts.
The overall scheme is broken down into 15 zones (each a scheme in itself), and coniste to works along the main waterflows in South Galway and includes, Central Gort lowlands (From Blackrock to Coole to-Kinvara), Thoor Ballylee Castle, Gort Town and satellite areas wuch as Labane, Cockstown, Tullira, Termon, Roo, Lough Bunny)
The main scheme can be imagined as series of overflow channels that kick in to keep the different floodplains within a Target Maximum Flood Level. The overflow channels, which were first mentioned in 1960, unsurprising, mainly follow the current overflows we see in extreme weather events.
While detailed analysis needs to be done, it appears that the scheme will reduce peak flood levels in a 1-in-a-100 -year flooding across the main floodplains (an average peak level reduction of 1.4m, some more, some less). This reduction in peak levels, with additional works, could offer substantial benefit in eliminating flooding to residential and non-residential properties, as well as maintaining access on strategic routes. This reduction in peak levels will reduce flooding risk on 638 ha of land, (463 ha of which is agricultural land).
One key benefit of the proposed scheme is that we won’t have whole communities isolated any more – A 3 month cut-off for communities in Rinrush will be fully alleviated – this is a substantial benefit.
The Emerging Engineering Scheme, for the design 1:110 event, will:
Alleviate flood risk to residential and non-residential properties with an appropriate freeboard,
Ensure the main route ways and important strategic access routes across the study area are accessible throughout the design flood event
Provide access to communities cut-off by flooding •Alleviate flood risk to farm buildings and farmland and therefore improve the economy and prospects of the Gort Lowlands area,
Protect the sensitive turlough habitats and groundwater resource from pollution arising from flooded farm slatted shed complexes,
Alleviate flood risk at important heritage and cultural sites including Thoor Ballylee castle and visitor centre, Coole park gardens and visitor centre and Kiltartan Church, and •
Facilitate potential future railway line raising works at Castletown to ensure uninterrupted connectivity along the Western Corridor Rail Network.
While extreme flood peak levels will be reduced and overall flooding duration will be reduced by several weeks, it appears that there will still be long flooding duration on land – so the proposed solution is managing the ’emergency’ overflow (as was designed) but there is still a substantial amount of water stored in the Turloughs which will drain at an unchanged rate.
One of the most controversial aspects of the report is the requirement for a new culvert under the M18 motorway. In 2006, we indicated to TII (NRA at the time) that their engineering design was under-designed compared to flows outlined in different reports but this was ignored. The substantial costs of this culvert don’t appear to be included in the scheme cost (detail not there yet) and nor should they be. This area is under-review and so we will await for TII to make good on their mistakes of the past.
One area that is concerning is that some of the Target Maximum flood levels appear to be higher than anticipated. The Target Maximum Flood level for Coole will still substantially flood the Walled Garden and Coole Lake Level is a a key part in overall South Galway flooding dynamics.
Unfortunately, this isn’t a one-size fits all solution – water dynamics will often dictate limits and some peak-levels won’t be reduced equally.
Again, this is a very initial summary, more detailed analysis needs to be done and exact details should emerge through a public consultation process that will start within the week.
The feasibility report contains initial indicative cost benefit analysis and indicates that the ‘Net Present Value of Benefits’ of the scheme (savings that a flood relief solution will create) will be close to €22 Million , and is mainly comprised of benefits from saving homes flooding , M18 Motorway flooding, business and farm buildings being flooded, flooding of structures and areas of significant cultural and heritage importance including Thoor Ballylee Castle and visitor Centre, Coole Park gardens and visitor centre, Kiltartan Church and roads being closed. Also adding the benefit are prolonged duration, road traffic disruptions and rail disruption.
Scheme costs associated with the flood relief channel and culvert works, road raising and flood relief roads, flood protection embankment and wall works, flood over-pumping facilities, drainage works, accommodation works, and channel, embankment and swallow hole maintenance works. These are not broken down in the feasibility study but indicative costs are put at €14 Million (ex VAT) but there are additional costs on ‘Whole-life-costs’ to be considered. We would also assume that the feasibility report itself will also be added in as a cost. The finals costs will emerge upon a selecting the preferred scheme but this feasibility study has concluded that these benefit will outweigh the costs and that the scheme at this stage is potentially feasible. Any modifications to the M18 culverts could also be substantial but this seems to be treated outside the scope of this scheme but be under TII remit.
Even if the projected costs reach the €22m this is a far cry from the €48 Million price tag given in the previous Jenning’s O’ Donovan Report.
There are many aspects of the proposed emerging scheme that need to be understood and considered. A public consolidation phase is commencing on the Emerging Preferred Scheme by means of an online public consultation event on the project website www.southgalwayfrs.ie where people can look at maps and get details of the scheme and talk to the consultants. I would advise people to engage with this process to get a better understanding of the design and impact so the flood relief process and give any feedback regarding the scheme.
Firstly, this is a very very welcome development – a feasbile flooding solution – something that has never been proposed to the the communities of South Galway over four decades. You have to appreciate the overall scope and complexity of the flooding so its a very impressive to be at the stage where we can discuss the proposed solution.
It’s too early to gauge the reaction on-the-ground to this report but overall I think it will be mixed. There is not doubt that there are huge pluses as it offers substantial benefit when it comes to homes, business and access around South Galway. We won’t have that isolation we have had in the past an that is a huge benefit. I think this will be received very positively by most people as the whole of South Galway has been badly affected here.
On the other, I think that landowner expectations would have been that it won’t have reduced the levels much more than what’s being proposed because once the peak has been manged, it’s down to the normal Turlough drainage – and so while it will save some land from flooding and will shorten flood duration by a few weeks at most -the overall flooding durations can still be significant .
We will also need clarifications. We need to understand more on the Maximum Turlough Levels and why these levels are higher than anticipated. We also need to understand some of the controversial areas like M18 culverts and what the plan is here.
Our advice to the public is to get informed as much as you can in the public consultation and give your feedback.
The Gort Lowlands Groundwater Flood Modelling Report report details the results of research into the South Galway karst network. The work was funded by Geological Survey Ireland (GSI), with additional support from Galway County Council and the Office of Public Works, and was carried out by Trinity College Dublin in collaboration with GSI as part of the 2016-2019 GWFlood project.
This was kickstarted in 2016 by a collaboration between the then OPW Minister Sean Canney and Denis Naughten.
The report (108 Pages) provides a details on the development of a complex hydraulic model over several years in order to model the complex groundwater- surface water interactions in the area, as well as enabling quantification of freshwater discharge into the Atlantic Ocean at Kinvara Bay.
The model is then used to provide a statistical analysis of return periods of different groundwater flood events in the catchment, as well as making predictions as to the likely impact of climate change on the frequency of such events.