Water levels

We monitor and record water levels on lochs, rivers and coastlines around Scotland, producing valuable information used by businesses, households and leisure users.

We monitor water levels at 392 sites throughout Scotland. Most of the stations are situated on rivers, but we also collect data from several tide and loch level recorders.

Why are water levels monitored?

The main reason that we record water levels is to manage water resources.

Water levels are converted to flow at most river gauging stations. Knowledge of the flow in a catchment is important in order to effectively manage that water – for instance, when issuing licenses for water abstractions and the control of pollution. Flow is also used in evaluating changes in the environment such as climate change, for example.

Fishermen, canoeists and other leisure users can use our data on water levels to help with planning their activities.

Water level monitoring is also an important factor in informing flood management for businesses and households.

To help users gain a greater understanding of why water levels are monitored and how the information can be used, we have produced a series of frequently-asked questions.

In time, we hope expand this area of our website to include other parameters, such as water temperature and water quality.

How is the information gathered?

Water level data is collected at gauging stations using a variety of electronic sensors and data loggers.

Data from these telemetry stations is collected automatically at least once a day – sometimes more frequently depending on telemetry linkages or, if required, for operational reasons. It is then updated on our online pages.

The data management system which updates the information displayed online is the same system that collects data for our flood warning service. During flood warning events, if the data feed to the website adversely affects performance for flood warning purposes, then it is possible that the river level data feed to the website will be temporarily disabled, although this will only be done if absolutely necessary.

Read a feature about how we gather water level data.

How is the information interpreted?

Our water level data pageprovides level data for the last few days for 335 of our 392 stations.

The level graphs show the change in level over the past two days relative to a local datum, although this level may not directly represent the depth of water between the bed and the surface.

Increases in water levels are normally associated with rainfall in the catchment. However, certain sites are subject to artificial control – for instance, hydropower stations may artificially influence the level of the river. Some stations are tidal sites or river level sites affected by the tide – at these stations, the water level may rise and fall several metres twice each day.

To give the user some perspective of each site’s relative level, figures for the maximum, minimum and average of the recorded levels are shown. These figures are based on our digital water level records and it is possible that higher or lower values have been recorded, but are not available in digital format.

  • The maximum value given is the highest level ever recorded at the station. By definition this may not be exceeded for some time.
  • The minimum level given is the minimum level on record and may be the result of an extreme event. When considering low levels, it should be understood that bed conditions can vary naturally from year to year, affecting the level recorded at low flows.

Occasionally, data for a site may be unavailable or incorrect. This is generally caused by a failure with instrumentation, the telemetry communications network or one of the computer systems that process the data.

Problems will generally be resolved within a period of a day but may take up to a week, depending on the nature of the problem. Where a problem is expected to last longer than a few days, an explanatory note will be placed in the comments on the graph page for the station.

Contact us

For more information about water level monitoring or how to interpret and use data, please contact us.