Water Levels
Water levels on the River Shannon are managed using gates and sluices at the outlets of the three major lakes, and sluices and weirs at Jamestown, Roosky, Tarmonbarry, Meelick, and the New Cut. Despite these operations, the shallow gradient and natural restrictions prevent full control, especially during floods. River levels are mainly determined by rainfall in the catchment area.
| Location | Ordinary summer level (metersm) | Daily water level (metersm) | Rainfall (millimetersmm) | NumberNo. of sluices | Sluices open |
|---|---|---|---|---|---|
| Drumshanbo (L. Allen) | 48.16 | 48.51 | -Not applicable | -Not applicable | -Not applicable |
| Clarendon Lock Upper | 44.20 | 44.14 | -Not applicable | -Not applicable | -Not applicable |
| Clarendon Lock Lower | 42.98 | 43.06 | -Not applicable | -Not applicable | -Not applicable |
| Jamestown Sluices | 42.98 | 43.02 | -Not applicable | 12 | 0.5 |
| Albert Lock Upper | 42.98 | 42.90 | -Not applicable | -Not applicable | -Not applicable |
| Albert Lock Lower | 41.15 | 41.01 | -Not applicable | -Not applicable | -Not applicable |
| Roosky Lock Upper | 41.15 | 41.03 | -Not applicable | 12 | 0 |
| Roosky Lock Lower | 40.14 | 40.08 | -Not applicable | 12 | 0 |
| Tarmonbarry Lock Upper | 40.14 | 39.93 | -Not applicable | 12 | 0 |
| Tarmonbarry Lock Lower | 37.49 | 37.58 | -Not applicable | 12 | 0 |
| Lough Ree | 37.49 | 37.60 | -Not applicable | -Not applicable | -Not applicable |
| Athlone Lock Upper | 37.49 | 37.51 | -Not applicable | 15 | 5 |
| Athlone Lock Lower | 35.36 | 35.68 | -Not applicable | 15 | 5 |
| Pollboy Lock Upper | 37.00 | 37.46 | -Not applicable | -Not applicable | -Not applicable |
| Pollboy Lock Lower | 35.35 | 35.51 | -Not applicable | -Not applicable | -Not applicable |
| Banagher (OPW Gauge) | 35.36 | 35.35 | -Not applicable | -Not applicable | -Not applicable |
| Victoria Lock (New Cut) | -Not applicable | -Not applicable | -Not applicable | 18 | 4 |
| Victoria Lock (Meelick) (Tilting weir: 50% Up) | -Not applicable | -Not applicable | -Not applicable | 12 | 2 |
| Victoria Lock Upper | 35.36 | 35.17 | -Not applicable | -Not applicable | -Not applicable |
| Victoria Lock Lower | 33.38 | 33.51 | -Not applicable | -Not applicable | -Not applicable |
| Portumna Bridge | 33.38 | 33.53 | -Not applicable | -Not applicable | -Not applicable |
Water Levels are relative to Poolbeg Datum
Banagher target level 35.31 to 35.41
Water level and the rainfall for previous 24 hours are read at 9:30 am
FAQ
Yes of course. The table provides daily water level data for various locations along the Shannon River. Here's a breakdown of its components:
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Location: This column lists the specific locations where water level readings are being taken. These locations include locks, bridges, and other points of interest along the river.
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Date: This column indicates the date and time when the water level readings were recorded.
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Upper Sill (metres): This column shows the height of the upper sill or crest of the structure (lock, weir, etc.) at that location, measured in meters.
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Lower Sill (metres): This column shows the height of the lower sill or base of the structure, also measured in meters.
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Daily Water Level (metres): This column displays the current water level at that location, measured in meters.
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Rain Fall (mm): This column records the amount of rainfall recorded in millimeters within a specific time period (i.e. the previous 24 hours).
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Sluices Open: This column indicates the status of the sluices (gates or valves) at the location. It shows the number of sluices open out of the total.
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Tilting Weirs: This column only applies to Meelick and indicates the status of any tilting weirs present at the location. The range of values are as follows:
- All Down
- 25% Up
- 50% Up
- 75% Up
- 100% Up
Water levels are managed on the River Shannon through the operation of gates and sluices at the outlets of the three major lakes and the operation of sluices and weirs at Jamestown, Roosky, Tarmonbarry, Meelick and the New Cut. These operations influence the levels on the Shannon but due to the shallow gradient of the river and the many natural restrictions along its course, the levels cannot be fully controlled especially when the Shannon is in flood. The river level is primarily the result of the amount of rain that falls on the river catchment area.
The water level on Lough Allen, Lough Ree and Lough Derg are managed by the ESB. More information can be found on the website: https://rivershannongroup.ie/.
Waterways Ireland manages the sluices and weirs at Jamestown, Roosky, Tarmonbarry and Meelick and the New Cut. The function of these weirs is to maintain water levels in the summer periods to allow boats to use the waterways. When all gates at the weirs are open, there is no further action to prevent further rising water level. At this stage the water is running through all open gates and over the adjacent weir.
Please submit a general enquiry via our Contact us form and include all the relevant dates and details of the information required. We will endeavour to respond as soon as possible.
There is daily communication and a coordinated approach to management of the water levels between Waterways Ireland and the ESB. ESB manages the levels for electricity production, ensuring the safety of the embankments and dams. Waterways Ireland manage the levels for navigation.
The ESB has a statutory role to generate electricity at Ardnacrusha. The relevant legislation is the Shannon Electricity Act 1925, Electricity Supply Act 1927 and Electricity Supply (Amendment) Act 1934. In broad terms, this legislation permits the ESB to generate electricity at Ardnacrusha and to manage the weirs, sluices and other works that are part of the Shannon Scheme.
Learn more about the role of the ESB in managing water levels.
Waterways Ireland is a navigation authority established under statute. It is responsible for the management, maintenance and development of those waterways principally for recreation purposes.
Waterways Ireland takes water level readings for the areas under their remit by 09.30 daily. However, the weekend's readings are only published on Monday morning.