Dáil Éireann Debate, Tuesday - 15 November 2022
220. Deputy Seán Canney asked the Minister for Public Expenditure and Reform the progress that has been made on the creation of a single authority to control the flow of water in the River Shannon; and if he will make a statement on the matter. [56097/22]
Amharc ar fhreagra221. Deputy Seán Canney asked the Minister for Public Expenditure and Reform the work that has been undertaken to reduce the level of water in the three main lakes on the River Shannon to prevent winter flooding; and if he will make a statement on the matter. [56098/22]
Amharc ar fhreagra222. Deputy Seán Canney asked the Minister for Public Expenditure and Reform the progress that has been made on the removal of pinch points in the Shannon callows; and if he will make a statement on the matter. [56099/22]
Amharc ar fhreagra223. Deputy Seán Canney asked the Minister for Public Expenditure and Reform the involvement that the OPW has had with ESB, Waterways Ireland and the various local authorities along the river Shannon to prevent winter flooding; and if he will make a statement on the matter. [56100/22]
Amharc ar fhreagraI propose to take Questions Nos. 220 to 223, inclusive, together.
The Deputy will be aware that the Shannon Flood Risk State Agency Co-ordination Working Group was established in 2016 by the Government to enhance the ongoing co-operation across the various state agencies involved with the River Shannon. The Group recently met in Athlone on 20th October 2022. At that meeting, the Group discussed a range of issues relating to work underway to assist with flood risk management along the River Shannon including the project for the removal of the pinch points through the Callows region between Athlone and Meelick weir.
Work is advancing to progress this project for the Shannon Callows region. A Steering Group has been established to oversee the project and a brief is currently being finalised for the appointment of a consultant to carry out the initial analysis and design work. Waterways Ireland, on behalf of the Shannon Group, will act as the Contracting Authority for this project.
The ESB, as a member of the Shannon Group, has provided the OPW with the following information in relation to its actions regarding the management of water levels on Lough Allen, Lough Ree and Lough Derg, and the management of water levels at Parteen weir.
The Shannon catchment has experienced high levels of rainfall over the last number of weeks and particularly since late-September. This has resulted in increasing water levels in the River Shannon and its tributaries.
All lakes were at or below the target levels as set out in the ESB’s regulations and guidelines for control of the River Shannon in advance of the aforementioned rainfall which commenced towards the end of September.
Specifically:
a. Lough Allen was below the normal operating band (48.7 – 49.1 mOD Poolbeg) until 4th October 2022.
b. Lough Ree was below the target level for the end of August (37.49 mOD Poolbeg) until 6th October 2022, with all sluices in Athlone closed (due to rising callows levels) on the 17th October 2022.
c. Lough Derg levels were within the normal operating band until increased inflows greater than station throughput caused it to enter flood on Thursday 3rd November 2022.
The capacity available in the lakes by being at or below target levels has now been used up as a result of the rainfall that has fallen on the Shannon catchment since the end of September.
The rate at which the water travels to Ardnacrusha is primarily a result of the natural topography of the river and the natural restrictions in the river. It takes many days for water to travel down the Shannon. All of the water arriving at Parteen weir is discharged either via Ardnacrusha station or down the old Shannon channel. The ESB does not store any water upstream of Parteen weir in the Parteen Basin.
In a flood situation, (Lough Derg is currently in flood since last week), the ESB discharges the most amount of water operationally possible through Ardnacrusha station via the Headrace canal away from flood prone areas of the Lower Shannon.
The ESB continues to maximise the discharge of water from Lough Derg via Parteen weir. Discharge at Parteen weir down the old River Shannon Channel as at Thursday, 10th November was 135 m3/s. This is combined with discharge from Ardnacrusha Station which is operating at full throughput operationally possible (approximately 368 m3/s currently).
Discharging more water than the current volume would result in lowering water levels in Parteen Basin and the Headrace canal below safe operating limits with the risk of causing stability issues to the Category A Earthen Embankment Dams that form Parteen Basin and the Headrace canal. The ESB can only manage the flow of water as it arrives at Parteen weir from Lough Derg. The water flow from Lough Derg to Parteen Basin is restricted by the flow capacity of the outlet channel from Lough Derg at Killaloe. The capacity restriction acts like a bottleneck limiting the discharge from Lough Derg. The ESB will continue to maximise the discharge of water from Lough Derg within its Dam Safety constraints.
Predicted water levels and expected discharge amounts based on the latest Met Éireann forecast as well as water levels throughout the three lakes and Ardnacrusha discharges are available on the ESB’s website at: Hydrometric Information (esb.ie).
The Deputy will recall that I committed to undertaking an examination of the legislative landscape including a review of the current regulatory environment underpinning the members of the Shannon Flood Risk State Agency Co-ordination Working Group.
On the recommendation of the Attorney General, the OPW obtained legal services to support the examination of the legislative powers underpinning all of the bodies involved. The legal analysis has been carried out and the outcome has informed a proposed approach which is currently under consideration.
