Risk/opportunity:(from the Climate Change Risk Assessment for Scotland 2012):
BD5 Species unable to track changing climate space • BD13 Water quality and pollution risks • BD14 Ecosystems risks due to low flow and increased water demand

Narratives: Water quality and availability

SCCAP theme: Natural environment

SCCAP objectives:
N1: Understand the effects of climate change and their impacts on natural environment

Latest figures

Number of SEPA monitoring stations recording temperature data:

Water quality monitoring stations (2014): 24

Hydrology monitoring stations (2013): 32

At a glance
  • Monitoring is essential for provision of accurate assessment of climate change pressures and impacts and to enable more focussed and effective management.
  • Currently, there are limited long-term, quality controlled water temperature data available in Scotland but there has been a steady increase over the past decade.
  • A national temperature monitoring network is being established: the Scotland River Temperature Monitoring Network (SRTMN)

Current and projected changes to Scotland’s climate have the potential to significantly impact upon the country’s freshwater systems. Rising water temperatures and an increase in extreme temperature events combined with changes in precipitation patterns are of particular importance to surface water ecosystems, with a number of potential areas of concern:

  • Impacts on the growth and survivorship of freshwater fish
  • Enhanced plant/algal growth due to increased temperature
  • Changing the favourability of conditions for both native and non-native (including invasive) species
  • When combined with the presence of diffuse or point source pollution the impact upon ecosystem functions can be particularly severe.
    • Warmer standing waters receiving high nutrient run-off as a result of greater intensity rainfall events could exacerbate algal blooms and eutrophication and increase loading of pollutants to the sea, increasing the risk of the failure of microbiological standards in bathing beaches and shellfish waters.
    • Reduced flow during summer months will result in greater and more rapid fluctuations in surface water temperature resulting in direct impacts on fish populations and indirect consequences by exacerbating the effects of pollution.

Monitoring is essential in order to be able to provide an accurate assessment of pressures and impacts and to therefore enable more focussed and effective management. However, currently, there are limited long-term, quality controlled water temperature data available in Scotland (Scottish Government, 2015a).

The indicator draws on data provided by the Scottish Environment Protection Agency (SEPA) regarding their water monitoring stations which routinely gather data on water temperature[1].

Related indicators:

NB24 Proportion of water bodies not meeting Good Overall Status

NB27 Summer low flow events in Scottish rivers (Normalised Flow Index)

NB31b Condition and distribution of climate sensitive species: Abundance of Arctic charr in freshwater lochs

NB39 Freshwater habitats with reported presence of key invasive non-native species (INNS)

[1] Current developments in this area, with regard to the establishment of the Scotland River Temperature Monitoring Network (SRTMN), will be captured in any future update.


There has been a steady increase in the number of SEPA’s monitoring stations (water quality and hydrology stations) routinely recording temperature information (Figure 1).

However, in the case of at least the hydrology monitoring stations, water temperature measurements were not subject to quality control during this period. The equipment was primarily designed to capture flow and level data and the ability to accurately collect additional parameters was not checked outside the initial factory calibration of the instrument[1] (SEPA, 2014).

The Co-Ordinated Agenda for Marine, Environment and Rural Affairs Scotland (CAMERAS) have undertaken a review of freshwater monitoring in Scotland, highlighting the scarcity of available information and the need to establish a national temperature monitoring network (Scottish Government, 2011). They established that there are very few long-term, high resolution temperature data sets available which enable assessment of temperature variability, and those that do exist are restricted to a few small catchments.  Furthermore, there are very few which have adequate quality control procedures in place which enable certainty that any observed trends are genuine (CAMERAS, 2015).


Figure 1 SEPA monitoring stations which also record temperature data

[1] The one exception to this is Carbrach gauging station, which had a dedicated water temperature sensor and should therefore provide better quality data

In 2007, the Water Framework Directive (WFD) introduced the need for a broader, more holistic approach to monitoring and classifying Scotland’s aquatic environment. Implementation of the WFD has resulted in some substantial changes in the monitoring of Scotland’s freshwater system, with associated increase in the number of monitoring locations collecting temperature information. SEPA’s monitoring strategy is to ensure that sufficient information is gathered to enable the measurement of progress towards WFD objectives with adequate statistical confidence and confirm whether their regulatory approach is delivering as intended (SEPA, 2007b).

The WFD specifies three categories of monitoring which have different but complementary purposes: surveillance, operational and investigative.

  • Surveillance monitoring network enables ongoing assessment of long-term changes across the country
  • Operational monitoring network is driven by risk assessments and is largely located in areas of identified risk
  • Investigative monitoring network is reactive (and transient) to emerging risks or unforeseen events (SEPA, 2007b)

The majority of sites, however, are concentrated in areas of high population density or agricultural activity which are not necessarily the areas of particular concern regarding the impacts of temperature on freshwater habitats. Furthermore, as the majority of monitoring locations do not routinely collect temperature information, nor apply adequate quality control to the collection of data, the availability of adequate monitoring has been very sparse.

In response to CAMERAS review of freshwater monitoring, a national temperature monitoring network (in collaboration with SEPA, other CAMERAS’ partners and fisheries organisations) is being established (the aim is to be in place for Summer 2017). The Scotland River Temperature Monitoring Network (SRTMN) aims to address the following objectives (Scottish Government, 2015b):

  1. To characterise spatial and temporal variability in river thermal regimes for important salmon rivers across Scotland
  2. To identify the most climatically sensitive locations (sites to regions) and time-periods (seasons to days)
  3. To improve understanding of hydrological, climatological and basin/site controls and assess buffering of water temperature by non-climatic factors
  4. To develop large scale spatial models to predict future river temperature changes based on climate and hydrological change scenarios
  5. To assess mitigation and adaptation strategies for high temperature
  6. To assess long-term trends in river water temperature

It is intended that annual data reports and analyses will provide an evidence base on changing temperatures in Scottish rivers within a carefully quality controlled monitoring setup that can inform local fisheries management and adaptation strategy at a local level (Scottish Government, 2015b). 


Currently the distribution of SEPA’s monitoring stations which capture temperature data is restricted geographically to a narrow band running across the country from the South West to North East (Figure 2).

Figure 2 Distribution of SEPA water monitoring stations which collect temperature data (2014)

The planned SRTMN is designed to capture temperature data based on strategic network design which can ensure that it meets research and management objectives. This will considerably change the overall distribution of routinely collected temperature data stations (Figure 3).

Figure 3 Proposed network for the Scotland River Temperature Monitoring Network (Scottish Government, 2015a)


Whilst there has been an increase in the number of monitoring stations routinely recording temperature information, if networks are unrepresentative of the environmental range then this limits the ability to utilise this information to predict for un-monitored locations, and thereby limits the usefulness of the monitoring network (Jackson et al, 2015). The large scale network design approach adopted by the SRTMN is intended to significantly improve this situation.

CAMERAS (2015) Scotland River Temperature Monitoring Network (SRTMN). Factsheet available at: http://www.camerasscotland.org/sites/default/files/images/Factsheet.pdf

Jackson, F.L., Malcolm, I.A., Anderson, H.L. & Hannah, D.M. (2015) A novel approach for the design of large scale temperature monitoring networks. IFM Specialist Conference 2015 Forestry and Fisheries – Where next? Available online at: http://www.gov.scot/Resource/0046/00469531.pdf

Scottish Government (2011) CAMERAS: Scottish Environmental Monitoring Strategy. Available online at: http://www.gov.scot/Publications/2011/12/05085553/0

Scottish Government (2015a) Scotland River Temperature Monitoring Network (SRTMN). Marine Scotland Topic Sheet v1 no. 90. Available online at: http://www.gov.scot/Resource/0047/00475286.pdf  

Scottish Government (2015b) Scotland River Temperature Monitoring Network (SRTMN) Available online at: http://www.gov.scot/Topics/marine/Salmon-Trout-Coarse/Freshwater/Monitoring/temperature

SEPA (2007a) Significant water management issues in the Scotland river basin district. Significant Water Management Issues (SWMI) Report. Available online at: https://www.sepa.org.uk/media/37765/significant-water-management-issues_scotland.pdf

SEPA (2007b) Scotland’s WFD aquatic monitoring strategy. Available online at: https://www.sepa.org.uk/environment/water/monitoring/

SEPA (2014) Personal communication

Mark Hallard and Janet Shepherd (SEPA): provision of monitoring station data