It has now been over three years since South Galway got ravaged by severe flooding events and there is a growing concern amongst residents in the area that the delays in flood relief solutions will increase risk of them suffering a major flood event again.
We are already two years into the project and we are a year behind schedule. We naturally have concerns going forward that more delays will stack up and increase the chances of getting hit with another flooding crisis before the solution is in place.
Despite the delays, we are however, positive about the work done to date. This part of the project was always going to be difficult. The underground network is too complex to understand by normal means, so we needed to get the right expertise in.
Minister Sean Canney was very proactive at the time and brought GSI on board early in this project who brought in (and hired ) experts from Trinity College Dublin in turlough and underground network hydrology.
Hydrology model
Their goal was to build a hydrology model of South Galway that could be used to understand future flooding scenarios and to evaluate proposed solutions. This model needed to be highly accurate and have rigorous testing and validation to ensure we will have sustainable solution.” he said.
The process is very research and data intensive and the key data sets needed to build an accurate model are historical rainfall and turlough levels and a detailed overground topography of South Galway. With this data and the right hydrology expertise – you can make sense of this.
This expertise is like looking at a spike in a Turlough level like a heart-beat and then listening for a pulse in a series of other downstream Turloughs. The strength of that pulse and its delay (or latency ) over hours or days will help build a picture of the underground network which can then be modelled as set of interlinked channels with different capacities.
To get the accuracy here, this data needs to be collected over several years. There have been several turloughs monitored in the area over the past 10 years but not enough to build up an accurate picture.
Since the flooding in 2016 GSI have added a large number of additional turlough level monitors to help get a better picture but again without having peak events, it can be difficult to get accuracy required. GSI was also able to hook into an EU project called Copernicus that took Satellite photos (four photos every six days ) and has been doing this for the past six years across the entire country.
Turlough levels
These images are being analysed by experts to get approximate Turlough levels linked to rainfall levents. With the topography data is it is therefore possible to get very good accuracy of the change in Turlough Volumes – which is essential for the catchment hydrology model
For the topography maps, South Galway has (Mostly ) been scanned by LIDAR which gives a model of the region down to very fine accuracy/granularity. This can be used to really understand equating changes in turlough levels to changes in volume. It can also be used to understand the turlough overflows and potential path of water. All of this information is analysed by Trinity College to produce a hydrology model of South Galway that can then be used for feasibility study.
Getting to grips with the research analysis and development of this hydrology model is the most important part of this flood relief project and that is essentially the main bulk of the work over the past two years. Other factors in the delay were additional areas of analysis from the key areas on public consultation days.
This model was supposed to be ready within a specific time period to be used by the Engineering Design Consultants, Ryan Hanley but it has probably taken GSI and TCD an extra year to get this to a level of accuracy and calibration that was needed. A flood relief solution for South Galway in 2023 would make it a time span of 7 consecutive winters since our last peak flood which means it less likely that we’ll be able to dodge another major flood in that time period”
Originally, the flood relief solution was to be in place by 2022 but the latest timeline its looking like 2023 – if all goes well. The feasibility study will now be complete by the end of 2019 and will result in a cost-benefit analysis of the flooding solution which again could have a major impact on the project.
Haven’t seen the worst yet
One positive effect of having a more accurate hydrology model is that we may be able to get a more realistic measure of actual flooding scenarios, with climate change factors added in. We suspect that this analysis will show that we haven’t seen the worst floods by a long-shot, and therefore the overall benefit that we would get from a flood-relief solution could rise.”
A year’s delay is hard to take but it’s a difficult balancing act. We want a quick solution here because our community is very vulnerable, but we also want something sustainable that we don’t have be going back to the drawing board in 10 years’ time. We’ve had to put up with these band-aid kind of solutions in the past but we now have a real chance to put a sustainable solution in so if the extra year allow us a more sustainable solution then I think we should tolerate this.
We shouldn’t however accept any more delays and the key ask of the SGFRC is that Galway County Council and OPW get on top of these delays and see how we could streamline other parts of the process.
Could we for instance speed up the feasibility process by adding more compute resources to the projects (it takes days to run different scenarios ). Are there ways we can speed up the detailed design and ministerial confirmation? While the project could start in 2022, what immediate works could have the biggest impact and potentially alleviate some flooding by winter 2022. What can be done?
In mid-Feb 2019, due to the massive overspend on the cost of the children’s hospital, with the total figure now said to be coming in around €1.4b, it was announced that that OPW would have to shave €3 million from their flooding budget which would be taken from flood relief schemes. Schemes that have already been announced won’t be touched which means schemes that are in development, like the South Galway, Gort Lowlands Flood Relief Scheme, could be.
After a few winters of no peak flooding events, it can be very easy to relegate the trauma that our communities felt in the 2015/2016 flooding crisis as a thing of the past. In reality it is more like we have hundreds of people throughout South Galway holding a ticking time-bomb each winter wondering if it will go off. This is putting a mental strain on people.
We need to ensure that we keep flooding solutions as a top priority for South Galway. We would encourage communities in South Galway to assess their prospective candidates for the local elections in May for their commitment in prioritising this flood relief project for South Galway. For the sake of these people, we have to ensure that flooding as put up as a top priority for South Galway.
We want this project watched like a hawk, we want our project owners being proactive in addressing delays and speeding up the process and our local representatives to be active and demanding for this.
