The Channel at Caherawooneen

caherawooneen.jpgThe area of Caherawooneen, Loughcurra and Dungory East play a pivotal role in the flooding dynamics of South Galway.  In the severe winter flooding of 2015, these communities provided the final overland connection of flooded South Galway Turloughs to the sea and were instrumental in helping to alleviate the distraught Cahermore community from even more hardship.  People talk about needing a channel to the sea for South Galway and currently Caherawooneen provides this connectivity.  It does this at a cost though as it can no longer take the amount of water and frequency of flooding and this has negative impacts for the local community.    A properly designed and sized channel that can safely transport water through this area would be of great benefit to South Galway communities, including a benefit to these communities as well.

Location

Caherawooneen is an located close to Kinvara on the north of the Cahermore road about 3km from Kinvara.  At its North-West side it is bounded by Loughcurra and connects via Dungory East to the sea north of Dunguaire castle.

cah1.JPG

The map here shows the area in more detail.   There are two roads, Caherawooneen South and Caherawooneen North that link between Cahermore road and the Ardrahan road.

ca1.5.JPG

Caherawooneen has no permanently flowing water but has two marshy areas known locally as the ‘Moneens’ and they are around 11m above sea level.  The road between them has some small culverts to allow water to pass through them which can happen in moderate winters.  There are some swallow holes close to the  South ‘Mooneen’ that may have significant flows.

Severe Winter Flooding

With heavy winter rains these marshes will expand but when the South Galway Turloughs of Coole, Garryland, Caherglassaun and Cahermore fill up and overflow, this will flow through Caherawooneen all the way to the sea.   In the winter floods of 2009, there was a flow overland from Caherawooneen to the sea. In winter 2015 however, with the highest rainfall on record and with the creation of an emergency channel (in an effort to alleviate the situation in Cahermore) there was much more substantial flooding in Caherawooneen. There were additional emergency works done to keep water flowing through some pinch points in Caherawooneen/Loughcurra

This was the extent of the flooding when the Cahermore channel was flowing.

cah2.JPG

This flow lasted several weeks and is captured on some excellent done footage by Sean Brady Aerial photography.

Caherawooneen North-Loughcurra

Flow at Dungory East.

If we look at this in more detail we see the water overflowed from the Cahermore emergency channel to Caherawooneen South over the road, made its way across several fields and flowed across (flooded) the Caherawooneen North road.

cah10.JPG

From Caherawooneen North, the water flow became troublesome as it gathered in a field in Loughcurra north that was surrounded by higher land and had literally no way out. The levels kept rising so emergency channels were cut through in several places and several walls had to be removed to keep the water flowing.  These ‘Emergency channels’ are highlighted in red and removed walls in orange on the diagram below.

cah13.JPG

This shows the emergency channel (long red line) in Caherawooneen.

From then on, water flowed from Caherawooneen-North through Loughcurra.

cah16.JPG
Flows from Caherawooneen North, through Loughcurra North (Insert are snapshots from drone images from Sean Brady Aerial Photography)
Once the water could flow through Loughcurra then it had a more or less a free run from the there to the Ardrahan road, to the Ballindereen road  to the sea beside Dunguaire Castle.

cah15.JPG

These emergency works succeeded in keeping the water moving from Caherawooneen to the sea.

Flooding Impacts

One of the first things to highlight in Caherawooneen and Loughcurra is that in 1995, 2009, and 2016, no houses were flooded – this is mainly farmland.  From Cahermore, these lands are more or less (with some exceptions highlighted) downhill to the sea. There are however several other impacts to consider.

Firstly, both Caherawooneen roads flood and this restricts access to many families in the area . For instance, in order to get to Gort, and because the Cahermore road was closed, people had to go via Kinvara and Ardrahan adding an additional 14km for a round-trip to Gort.  The same was true for many farmers in the area as access to the land the far side of floods could require an additional  journey and in some cases would require an additional 20km round-trip journey to tend the farm.  The two Caherawooneen roads were cut off for over 100 days.

The second major impact was on farm land where over 150 acres of land flooded for over a 3 month period.   This has both short-term and long-term impacts. The short-term is the land is unusable for almost the entire year and yield is well down on the farm. The long term impact is that it takes time for fields to recover. The following is a photograph taken exactly 1 year after the floods and you don’t have to be a rocket scientist to guess where the flood water level was as the yellowed grass on the right marks the flooded land.

IMG_4583.JPG

The emergency works carried also had many impacts.  Upstream in Cahermore an emergency channel had to be dug to save many houses there. This brought more water into Caherawooneen (an additional 3m3/sec)

channel1
The emergency channel at Cahermore (Courtesy of Sean Brady Aerial Photography)
From talking to local farmers, another big impact here was not necessarily the floods, but the emergency works. When emergency works are done during flooding then the soil was removed while the water was flowing.  The underlying soil had no protection and was washed way destroying the land and brining a lot of lot of sediment downstream. 

cah8.JPG
Emergency works carried out in Caherawooneen to alleviate flooding upstream (Courtesy of Sean Brady Aerial Photography)
When the flooding receded the farm land was damaged significantly and in some cases was not put back to it previous state. The following land in Loughcurra used to be a normal field but with the emergency works completed, this is how the land looks 1 year after the floods.

img_4603
This land in Loughcurra used to be normal field but was used for emergency works in Caherawooneen
cah18.JPG

cah19.JPG
Even some emergency channels that were put back didn’t leave land in same condition
One key worry of the farmers is that even with land that was put back to its ‘original state’ but not done to a good standard and it would threaten single farm payment subsidies as there are strict guidelines to conform to.

The emergency works were absolutely necessary and did save houses and it’s a credit to all concerned who enabled this – from the land owners, to Galway County council, OPW, our elected representatives, neighbours and friends.  We have to make sure though that the people that gave up their lands don’t end up in the same situation again. They, like everybody else, need a proper solution for this flooding situation rather then be faced with future emergency works that will impact their farms

Solution

The good news is that everybody could benefit from a proper solution to get water from Cahermore (and hence South Galway) to the sea but this needs to be done properly.  There was a preliminary study done in 2011 by Jennings-O’ Donovan and they highlighted in the South Galway Flood report a permanent overground channel from Cahermore to the sea. This is a snapshot of that report.

cah4.JPG

This also provided some indicative levels of a channel here:

cah9.JPG

  • (D)is Caherawooneen South Road (11.12m above sea level)
  • (E) is Caherawooneen North Road (9.09m above sea level)
  • (F) is the Ardrahan road (4.61 m above sea level)
  • (G) is the Kinvara Ballindereen road (3.25m above sea level)

This channel proposal was over 3 meters deep, and 3m at base with sloping sides. It also indicated the length of the channel from the South Moneen (D) to Kinvara Bridge at around 3 km.

This was a very preliminary proposal and didn’t progress because of Cost-Benefit issues.  The new solution proposal may be similar to this but better hydrology modelling after the 2016 floods will give a better understanding of channel sizing etc.

What is interesting is if we plot the course of the flow of water in Winter 2015 and the route the emergency works have taken. The diagram shows this route as a blue dashed line and it’s quite close for many sections of it but there are some deviations where the emergency works were carried out.

cah17.JPG

Sometimes I have to remind people that this is not a channel to drain Coole lake to the sea. This is a channel that acts as a storm drain that only flows whenever there are severe rains in South Galway and would remain dry otherwise.   Like any good storm drains, it should be properly sized, with proper culverts to contain and transport the necessary water safely to the sea. It’s now up to Galway County Council and their engineering consultants to get a proper overall solution designed and implemented.

Summary

Caherawooneen plays a vital role in South Galway flooding dynamics and it is the last route that water takes to the sea.  Flooding tends to happen in Caherawooneen when there is severe winter rains in South Galway. In winter 2015 the normal flooding however was exacerbated by the biggest rainfall that the South Galway has ever experienced and an emergency overflow channel from Cahermore as opened that caused more flooding in Caherawooneen.   Emergency works took place in Caherawooneen/ Loughcurra to keep the water flowing to the sea.  The main impacts were on access and farmland and in particular the state of the land post flood and post emergency works.

The water finds the easiest route and has clearly marked its path. We need a properly designed channel that will take the water from the lower South Galway basins during severe winter rains. The channel (or Storm drain) should benefit many communities of South Galway including the communities of Caherawooneen.

People have been repeating for years now – ‘It needs to start at the sea’ – This is place that South Galway flood relief needs to start and this should be one of the first parts of the project to complete.

David Murray

[PS : Special thanks to Joe Keane for bringing me around the area!]

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s