Scotland’s National Water Scarcity Plan 2020

Scotland’s National Water Scarcity Plan July 2020 For information on accessing this document in an alternative format or language please either contact SEPA by telephone on 03000 99 66 99 or by email to equalities@sepa.org.uk If you are a user of British Sign Language (BSL) the Contact Scotland BSL service gives you access to an online interpreter enabling you to communicate with us using sign language. http://contactscotland-bsl.org/ www.sepa.org.uk 03000 99 66 99 Strathallan House, Castle Business Park, Stirling, FK9 4TZ mailto:equalities@sepa.org.uk http://contactscotland-bsl.org/ http://www.sepa.org.uk/ Scotland’s National Water Scarcity Plan 3 Overview This is Scotland’s first national water scarcity plan, setting out how water resources will be managed prior to and during periods of prolonged dry weather. This is to ensure the correct balance is struck between protecting the environment and providing resource for human and economic activity. It sets out:  the high level principles;  what steps we and others are currently taking in preparation for periods of water scarcity;  what assessment methods we will use to determine the most appropriate response to water scarcity;  what action we will take during a period of water scarcity;  what action we expect others to take. Following consultation, SEPA has taken on board views from a range of interested parties and individuals and updated the plan accordingly. The plan will be reviewed as more experience is gained and tools are developed. Scotland’s National Water Scarcity Plan 4 Table of contents 1. INTRODUCTION ..................................................................................... 6 2. IMPACTS OF WATER SCARCITY ......................................................... 8 3. ROLES AND RESPONSIBILITIES ....................................................... 12 3.1. SEPA .................................................................................................. 13 3.2. SCOTTISH WATER ............................................................................ 15 3.3. SCOTTISH GOVERNMENT ............................................................... 15 3.4. OTHER ORGANISATIONS ................................................................ 16 4. DECIDING WHEN TO TAKE ACTION .................................................. 18 4.1. WATER SCARCITY LEVEL ............................................................... 18 4.2. HIERARCHY OF ACTION IN RESPONSE TO DRY WEATHER ....... 22 5. COMMUNICATION ............................................................................... 36 6. WAY FORWARD .................................................................................. 39 6.1. ACTION PLANS ................................................................................. 39 6.2. FUTURE PLANNING .......................................................................... 40 GLOSSARY .................................................................................................. 42 ANNEX 1 - WATER SAVING ADVICE ......................................................... 43 ANNEX 2 – WATER SCARCITY INDICES................................................... 44 ANNEX 3 – WATER SAVING MEASURES ................................................. 47 ANNEX 4 - CLARIFICATION OF CRITERIA USED TO DETERMINE SIGNIFICANT WATER SCARCITY ……………………………………………50 Scotland’s National Water Scarcity Plan 5 Update Summary Version Description v1.1 Revision to clarify when Significant Water Scarcity is reached (Annex 4) – July 2020 Scotland’s National Water Scarcity Plan 6 1. Introduction Although generally considered a wet country, Scotland can be vulnerable to periods of dry weather, which can result in pressure upon the environment and water users in some areas. In addition, climate change is likely to bring uncertainty and, with a projected decrease in summer rainfall, may exert pressure in areas that have not yet experienced water scarcity. It is vitally important that Scotland is prepared to deal with water scarcity both now and in the future and people work together to plan for and manage water scarcity events. This plan sets out how we will work with water users (authorised abstractors and recreational users) and key organisations, such as Scottish Water, to manage water resources during periods of low rainfall. All water users have a role to play to ensure that resources are used sustainably and the potential impact on the environment is reduced. The tables in section 4 set out the high level approach we would take with each sector to manage periods of water scarcity. Working closely with others, we may develop prioritised catchment specific triggers to better manage events at a local level (see section 6) where persistent problems occur. We will review this plan in conjunction with the river basin management plans and will update it as required as we learn from experience of managing our water resources during periods of prolonged dry weather. The measures in the river basin management plans will reduce the pressure on water resources during dry periods by improving current significant pressures on the water environment. The steps set out in the water scarcity plan are in addition to those steps which alone may not be sufficient to protect the environment and key water supplies in prolonged dry periods. https://www.sepa.org.uk/environment/water/river-basin-management-planning/ Scotland’s National Water Scarcity Plan 7 Scotland’s National Water Scarcity Plan 8 2. Impacts of water scarcity Dry weather conditions causing low river flows and loch levels are natural and the ecology can generally adapt to the natural range of conditions. If dry weather is prolonged however, there comes a point where environmental impacts do occur, and this is exacerbated when water is abstracted. Fortunately, we are not subjected to regular long term and widespread dry spells in Scotland. However, we do sometimes see localised and short-term dry periods which can cause environmental problems, and put stress on public water supplies and private abstractions as seen in the mid 1970s, 1984, 2003 and 2008. The impacts on abstractors will depend on the resilience of the systems within a particular area of the country. Areas with little storage (few or small reservoirs) will be affected by short dry periods, whereas groundwater and areas with greater storage can cope with longer dry periods before suffering from potential shortages. If an area rarely has extended dry periods then water resource supplies are often designed with less storage. Areas of the country which are more prone to dry periods may have more storage and may therefore be less vulnerable to short periods of dry weather. As river levels drop, the depth and width of the channel will contract and flow velocities will reduce. This may fragment the river and reduce the suitable habitat space. Over a longer time frame, lower rainfall will cause a drop in groundwater levels and spring flows which could cause lowering of water tables in wetlands. Drier weather will also cause an increased deficit of moisture in soils meaning less runoff into rivers and a greater need to irrigate crops. Drier soils can also increase the risk of flash floods if heavy rain follows dry weather. Scotland’s National Water Scarcity Plan 9 Fish populations can be affected in a number of ways. In very shallow rivers the oxygen content can fall (as the water temperature rises or through respiration by aquatic plants) causing fish kills. A low flow in a river may prevent migratory fish from moving upstream and disrupt food supplies by impacting on aquatic invertebrates. Scotland’s National Water Scarcity Plan 10 Climate Change predictions suggest that summers in Scotland are likely to get drier, potentially leading to an increase in summer water scarcity. Figure 1 shows a decrease in summer rainfall of 10-20% with a smaller change in the extreme northwest. Unlikely to be Central Likely to be drier than this projection drier than this Figure 1 Projected change in summer precipitation by the 2050s, showing the probability of drier summers under three scenarios1. The Scottish Government has set out how Scotland should adapt to climate change whilst ensuring we achieve sustainable economic growth. Visit the preparing for a new climate web page to find out more. 1 Figure taken from https://www.gov.uk/government/publications/adapting-to-climate-change uk-climate-projections-2009 UKCP09 probabilistic projections. The three projections relate to the 33, 50 and 67% probability levels from UKCP09 medium emissions scenario. http://www.scotland.gov.uk/Topics/Environment/climatechange/scotlands-action/adaptation https://www.gov.uk/government/publications/adapting-to-climate-change-uk-climate-projections-2009 https://www.gov.uk/government/publications/adapting-to-climate-change-uk-climate-projections-2009 Scotland’s National Water Scarcity Plan 11 If Scotland is to experience warmer, drier summers, there may be more periods of water scarcity with implications for water resource management particularly in areas with limited water storage. Drier summer months will put river catchments under more pressure from abstractions, reducing the available resource for water users. Lower summer flows would also reduce the ability of rivers to dilute pollutants with the possibility of increased treatment costs for dischargers. Scotland’s National Water Scarcity Plan 12 3. Roles and Responsibilities The successful management of water resources requires collaboration of all stakeholders to minimise impacts during periods of water scarcity. Organisations, companies and individuals should plan in advance to ensure they have taken all the steps to enable them to respond in a manner that will minimise the effects upon the environment, themselves and others. Households and businesses should always use water efficiently to limit pressure on water supplies and the environment. There are a number of useful sources of information regarding water saving advice for households and businesses which are summarised in Annex 1. These can lead to reduced energy consumption, lower costs and fewer greenhouse gas emissions. By further reducing water usage during dry periods, all water users can help extend the available resource. Abstraction and impoundment activities are authorised under the Water Environment (Controlled Activities) (Scotland) Regulations 2011 (CAR). The Regulations include a duty to use water efficiently; therefore we expect best practice to be undertaken as part of daily operations. Leakage and wastage should be kept to a minimum. The quantities of water abstracted should be the minimum required for that activity and techniques such as recirculation and water storage should be considered where appropriate. Any measure during a period of water scarcity should be in addition to day to day good practice. SEPA encourages operators to have contingency plans if the supply is essential for the smooth operation of their business. 1 Scotland’s National Water Scarcity Plan 13 The following bodies are responsible for water scarcity management: 3.1. SEPA SEPA’s key role is to protect the water environment. During dry periods, when the water environment comes under pressure, SEPA is required to balance the need for sustainable water use whilst protecting the environment. Whilst protecting the environment, SEPA can also allow temporary deterioration to protect key abstractors, provided the circumstances are a result of prolonged water scarcity and all practicable steps are taken to prevent environmental impact and do not compromise the recovery of the environment. Scotland’s National Water Scarcity Plan 14 The Water Environment (Controlled Activities) (Scotland) Regulations 2011 (CAR) SEPA regulates activities such as abstractions, impoundments, discharges and engineering works through CAR. Provisions under regulation 18 allow for a flexible approach to ensure swift but temporary action can be taken in emergency situations such as periods of water scarcity. This is commonly known as a Fast Track CAR variation and is explained in Scottish Government policy statement - use of CAR 2011 emergency provisions and detailed in SEPA regulatory method - CAR 2011 - Emergency Provisions and Accelerated Determination. During periods of dry weather SEPA will set up an internal Water Scarcity Management Group consisting of operational, science and communications staff to ensure decisions are made quickly using the most up to date information. SEPA monitors the ecology and water flows and levels of rivers and lochs throughout the year2 with more effort during periods of water scarcity. For example, during extensive dry periods SEPA will target increased monitoring to understand the impacts of low flows. The water scarcity indices described in section 4 combined with local evidence will determine what action to take. This information will be published on our website to allow people to act early and to show what action we are taking. 2 http://www.sepa.org.uk/environment/water/monitoring/ https://www.gov.scot/publications/implementing-water-environment-water-services-scotland-act-2003-use-car/pages/0/ https://www.gov.scot/publications/implementing-water-environment-water-services-scotland-act-2003-use-car/pages/0/ http://www.sepa.org.uk/regulations/water/guidance/ http://www.sepa.org.uk/regulations/water/guidance/ http://www.sepa.org.uk/environment/water/monitoring/ Scotland’s National Water Scarcity Plan 15 3.2. Scottish Water Scottish Water monitors its water supply sources throughout the year to make sure sufficient resource is available to meet customer demand. During prolonged dry weather when supply levels drop, drought contingency plans are put in place to maintain a constant drinking water supply. Plans have been developed for key supply sources and further prioritised plans are being developed. This water scarcity plan reflects the high level approach used with those plans and the Scottish Water tables (tables 5 and 6) are used primarily where a drought plan with specific measures has not been agreed with Scottish Water. Scottish Water works closely with SEPA and the Scottish Government to ensure that any changes to operating practice and new abstractions minimise the impacts on the environment and other users. Further work is being undertaken to assess areas which will be more vulnerable than others in the future. In addition, Scottish Water will work with their customers to encourage water saving measures with further reductions considered during prolonged dry periods. 3.3. Scottish Government The Scottish Ministers have established a clear policy and legislative framework to enable a balance to be struck between protecting public water supplies, the water environment and other users during periods of prolonged dry weather. Water orders may be made by Scottish Water where needed to protect public water supplies. Scotland’s National Water Scarcity Plan 16 The Water Resources (Scotland) Act 2013 This sets out the legal framework for Water Shortage Orders. Part 7 of the act says: 1) Scottish Water may propose to the Scottish Ministers that they make a water shortage order if it believes that there is— (a) a serious deficiency of water supplies in an area, or (b) a threat of a serious deficiency of water supplies in an area. A Water Shortage Order may permit Scottish Water to carry out various actions such as to gain access to land to abstract from an alternative source or to impose water saving measures on organisations or individuals if deemed necessary, including the imposition of hosepipe bans. The Water Resources (Scotland) Act 2013 can be found on the Scottish Government website here: The Act with a news briefing. As a period of prolonged dry weather continues, difficult decisions may have to be taken when there are competing priorities for water use. Ministers may issue a direction to SEPA, setting out how SEPA should use its powers to help deal with the emergency situation. Before issuing a direction, Ministers must take advice from SEPA and responses to any consultations with interested parties. Such action3 is most likely to be needed when water shortage has become widespread and severe and key water supplies have to be protected. 3.4. Other Organisations In managing water scarcity, SEPA, Scottish Water and the Scottish Government take advice from other bodies, such as Scottish Natural 3 https://www.gov.scot/publications/implementing-water-environment-water-services scotland-act-2003-use-car/pages/0/ https://www.gov.scot/policies/water/ https://www2.gov.scot/News/Releases/2012/06/scotland-water28062012 https://www.gov.scot/publications/implementing-water-environment-water-services-scotland-act-2003-use-car/pages/0/ https://www.gov.scot/publications/implementing-water-environment-water-services-scotland-act-2003-use-car/pages/0/ Scotland’s National Water Scarcity Plan 17 Heritage (SNH), fisheries boards and trusts4. Any proposal which could affect a designated site should be discussed with SNH at the earliest opportunity and actions which might affect the fish population should be discussed with the local fisheries trusts and boards. If the proposal is unlikely to damage the features of a SSSI or have a significant effect upon a European protected area or species then SEPA will consider authorising the application. Otherwise SEPA will consult SNH and if there is likely to be a significant effect on a European site or species, we will undertake an appropriate assessment and may refuse the proposal. It is critical therefore that potential impacts from any proposals are considered well in advance. 4 http://fms.scot/ http://fms.scot/ Scotland’s National Water Scarcity Plan 18 4. Deciding when to take action Problems caused by dry weather happen gradually and measures taken early can lessen the effects or prevent them from occurring. SEPA has therefore developed a staged approach to ensure the action taken is proportionate to the severity of the event. Analytical tools and monitoring allow us to measure the severity of a dry period and act accordingly. Other supporting local evidence such as ecological impacts (e.g. fisheries advice) water quality impacts, flow monitoring or feedback from authorised operators will be crucial to inform final decisions. Following experience of applying these indices in 2018, the criteria used to determine Significant Scarcity have been amended. Please see Annex 4. 4.1. Water scarcity level A water scarcity index is a measure of how exceptional a period of water scarcity is. SEPA has developed a water scarcity index to allow better planning and response to prolonged dry spells (see Annex 2) for more information on how it is calculated). This water scarcity index can be calculated using rainfall or flow data using departure from long term average figures and gives the following levels of warning: Table 1: SEPA’s Water Scarcity levels Normal conditions Water scarcity early warning Water scarcity alert Moderate water scarcity Significant water scarcity Extreme water scarcity Scotland’s National Water Scarcity Plan 19 The index can be calculated for different time periods. A 30 day index will be used for managing agricultural water usage and abstractions from rivers with little or no groundwater component. An index of 90 days picks up anomalies from the long term average and will assist with the early warning of water scarcity. This is a good compromise between using longer term data which won’t be sensitive enough to pick up changes in sources with little or no storage and using shorter term data (e.g. daily) which would not account for the effects of continued dry weather. SEPA will make use of the following indices: Table 2: 30, 90 and 180 day indices Indices Purpose 30 day rainfall and flow Managing abstractions from rivers, including agricultural abstractions. 90 day rainfall and flow Early warning of possible water shortages and to assess supplies with storage. 180 day rainfall and flow To assess cumulative impacts of longer term events. For public water supply, the period used will vary according to the storage available and the ‘critical period’ (length of time a reservoir takes to empty in its driest year). A similar approach would be taken for other users with storage reservoirs. Where appropriate, we would also use rainfall forecasts and soil moisture deficit in conjunction with water scarcity indices to provide early warning of a likely impact as shown in table 3 below. A catchment in the alert index alone will not be as at risk if the soil moisture deficit is low and rainfall is also expected. This is especially relevant for agricultural catchments where drier soils mean an increased requirement to irrigate crops. Scotland’s National Water Scarcity Plan 20 Table 3: Indication of soil moisture deficit and forecasted rainfall in relation to water scarcity Level Flows index OR Rainfall index + Soil moisture deficit + Rainfall (in 5 day forecast) Normal conditions <0.25 <0.25 0-20mm N/A Early Warning 0.25 0.25 20-60mm <30mm Alert 0.5 0.5 60-100mm <30mm Moderate scarcity 1.0 1.0 >100mm <50mm Significant scarcity5 2.0 2.0 >100mm <50mm Extreme water scarcity 2.5 2.5 >100mm <50mm Returned back to normal <0.25 <0.25 0-20mm N/A The water scarcity data provides us with early warning and context to assess the likely severity of an event. However the final decision to amend a CAR authorisation to limit abstraction rates to protect the environment or to allow more abstraction to maintain supplies will be based on additional local factors (see figure 2).The information will include data and expertise from third parties such as fisheries interests and operator data to explain current water levels within a reservoir for example. The indices also act as a trigger for further investigation such as catchment visits and increased monitoring and reporting. 5 Please see Annex 4 for updated definition of Significant Scarcity Scotland’s National Water Scarcity Plan 21 Water scarcity index Flow Index Rainfall index + + Rainfall forecast Soil moisture deficit De Rainfall forecast deficit Water scarcity level experience Water level and monitoring Factors used in decision making Reservoir levels Ecology monitoring and assessment (inc environmental standards) Impact on abstractors Impact on water users Figure 2: The main factors used in the decision to amend a CAR authorisation Scotland’s National Water Scarcity Plan 22 4.2. Hierarchy of action in response to dry weather There are various measures which can be taken to reduce the effects and limit the impact on the environment and people. We would expect all stakeholders to act responsibly and to work together to minimise the impacts and prolong the available resource. In the majority of cases it is expected that prior consideration of water resource management options should improve the reliability of water supplies and reduce environmental impact. We strongly encourage operators to minimise water use as far as possible as outlined in Annex 3 and draw up contingency plans for managing resources during periods of water scarcity to minimise the impact upon their business. The plans should also look ahead to build in resilience to possible effects of climate change (see section 6). Effort should be prioritised based on environmental risk and impact on business. As the effects of dry weather become more severe it may be necessary for us to progressively review authorised abstraction volumes and compensation flows from dams to mitigate impacts on people and the environment, using Regulation18 of the Water Environment (Controlled Activities) (Scotland) Regulations 2011 (CAR). The decision to implement the most appropriate solution set out in tables 4 - 8 will be based on a mixture of available information including the water scarcity level explained in the previous section together with local data, knowledge and experience. Once the level of risk drops we will progressively remove restrictions on abstractors and remove any changes put in place to protect the environment or public water supplies. It is important that operators maintain enough storage to meet the conditions set out in their authorisation. If an operator is having frequent problems with securing sufficient water during dry periods then we would welcome discussion of alternative sources or encourage consideration of alternatives such as water re-circulation or water storage. This is the first water scarcity plan in Scotland so we will learn from specific events and update our approach accordingly. During a period of water scarcity we will review the situation frequently to ensure measures are taken early to limit the impact on the environment and water users at that time and until conditions recover. Scotland’s National Water Scarcity Plan 23 Tables 4 - 8 below have been developed by SEPA to show an indicative hierarchy of actions for different sectors. The tables summarise the main steps likely to be involved but do not provide an exhaustive list of every possible action. As the situation improves SEPA will gradually remove any restrictions put in place. The steps are designed to trigger the consideration of action rather than being automatic. Each event will be a result of a combination of factors so it is important to allow flexibility to take those on board. Some steps may be more appropriate to bring forward and others to put back. For example, a CAR emergency notice may be issued sooner in a flashy catchment where alternative supplies are limited and the abstraction is key, e.g. a public water supply on a remote island. Similarly some steps are more appropriate in certain scenarios than others. E.g. environmental constraints may limit alternative supplies. Any changes to CAR authorisations, to allow more abstraction, restrict abstraction or to modify mitigation requirements will be evidence based using local knowledge and data. Steps such as leakage reduction are in addition to good practice. Scotland’s National Water Scarcity Plan 24 5 To be used in conjunction with measures in annex 3. 6 Levels coded as per table 1. 7 An example of the action that might be taken. 8 See table 3 9 Consider flexibility within operation, alternative supplies and water saving measures (see Annex 3) Scotland’s National Water Scarcity Plan 25 Scotland’s National Water Scarcity Plan 26 Scotland’s National Water Scarcity Plan 27 4.2.1. Scottish Water Scottish Water carries out extensive monitoring of their supply zones and provides weekly updates to SEPA with more frequent communication where required. During the extended dry period in the south west of Scotland in 2010, frequent dialogue between Scottish Water, SEPA and the Scottish Government ensured that there was successful management of potential water scarcity. The monitoring carried out by Scottish Water will be complemented by SEPA’s river monitoring data and predictive tools to give early warning of possible water scarcity and also to inform effective decision making. Scottish Water has an ongoing project, producing drought plans for their sources. The plans include colour coded operating rules which match the levels in table 5 below. The weekly update from Scottish Water shows whether sources are in normal operation or one of the coloured zones. SEPA’s hierarchy of action, shown in table 5 relates to Scottish Water’s reservoir control curves and reacts to the resource available in their reservoirs. Scotland’s National Water Scarcity Plan 28 11 To be used in conjunction with measures in annex 3. 12 Levels coded as per Scottish Water procedures. 13 An example of the action that might be taken. 14 See table 3 Scotland’s National Water Scarcity Plan 29 Scotland’s National Water Scarcity Plan 30 15 To be used in conjunction with measures in annex 3. 16 Levels coded as per table 1. 17 An example of the action that might be taken. 18 See table 3 Scotland’s National Water Scarcity Plan 31 Scotland’s National Water Scarcity Plan 32 19 To be used in conjunction with measures in annex 3. 20 Levels coded as per table 1. 21 An example of the action that might be taken. 22 See table 3 Scotland’s National Water Scarcity Plan 33 Scotland’s National Water Scarcity Plan 34 23 To be used in conjunction with measures in annex 3. 24 Levels coded as per table 1. 25 An example of the action that might be taken. 26 See table 3 27 Consider flexibility within operation, alternative supplies and water saving measures (see Annex 3) Scotland’s National Water Scarcity Plan 35 Scotland’s National Water Scarcity Plan 36 5. Communication Good communication will ensure extended periods of low rainfall don’t cause problems which escalate unnecessarily. We will provide early warning of prolonged dry weather so water users can take appropriate steps to minimise the impacts on their business and the environment. We will update our website to accommodate a range of information and advice that will assist operators, stakeholders and media. The frequency of updates will depend on the severity of the event, the potential impacts and rainfall forecast. We propose to include the following information on the website:  National plan  Sector based action hierarchy  Map displaying current river levels and long term rainfall data (example below)  Report on the current situation and summary of action being taken to mitigate the impacts  FAQs  Advice and useful links Scotland’s National Water Scarcity Plan 37 Scotland’s National Water Scarcity Plan 38 Operators should remain aware of the pressures on water resources and act accordingly. Any operators with concerns about meeting authorisation conditions should contact us at the earliest opportunity. You should be following good practice for your specific sector and be considerate of other water users in your area. There may be downstream private water supplies, other abstractors or sensitive sites. In prolonged dry conditions, we would recommend liaison with neighbours and other users to try and share the resource as much as possible. We can assist you in this process. In addition, information gathered at a local level can help inform decision making. Third parties can also take proactive measures to help out. We would encourage and support the consideration of action such as trapping and moving fish to avoid them being stranded. Many measures may be practicable and we would welcome early discussion of such initiatives. If people notice fish in distress they should contact SEPA and their local fishery board to make them aware as early as possible6. 6 http://fms.scot/ https://www.sepa.org.uk/contact/ http://fms.scot/ Scotland’s National Water Scarcity Plan 39 6. Way forward 6.1. Action Plans To complement and enhance this national plan, we will collaborate with stakeholders to develop a series of action plans, where appropriate, to better manage water scarcity at a local level. Whilst this national plan sets out the principles of water scarcity management, the action plans will identify local triggers that will initiate specific measures to be taken and include specific steps related to individual authorisations or groups of authorisations. The action plans could be prioritised in a similar way to how Scottish Water has prioritised plan development to areas most at risk. The action will be based on triggers initially at a catchment scale but could be refined where certain areas are particularly vulnerable. Scotland has a valuable agricultural sector that produces high quality food renowned across the world. Soft fruit and vegetable production largely based in the south and east of the country often requires large volumes of water to be abstracted from the water environment to irrigate crops. This typically occurs during dry periods when the resource is already under stress. If we are to experience drier summers then that pressure is likely to increase. We will liaise with the farming community and their representatives to develop a plan which will seek to implement appropriate measures to mitigate the impacts on the environment while endeavouring to achieve proportionate use of water. It is important that as much work as possible is done in advance to enable the sector to manage prolonged dry periods in a more efficient manner. We are already working with the farming sector to review catchments which have been highlighted in the RBMP as currently being under pressure; that work will complement and support water scarcity planning. By making information available to those who irrigate it gives them a chance to take appropriate and timely action. Scotland’s National Water Scarcity Plan 40 Funding is available for offline storage lagoons to collect and store water for irrigation in catchments identified as significantly impacted by abstraction for agriculture. These could provide additional water security where resources are under pressure already. See Annex 3 for more information. 6.2. Future planning The water scarcity plan will allow us to manage water resources in dry periods and contribute to the joined up approach set out in the river basin management plans. Page 4 of the Scotland River Basin Management Plan states that “Working together to secure the sustainable use of the water environment will help maximise the benefits a healthy water environment can bring for people and businesses. It will also help identify, and make use of, opportunities to contribute to our wider goals, including those for improved resilience to climate change, biodiversity, forestry, flood risk management, fisheries and sustainable land use.” 7 7 http://www.sepa.org.uk/media/163445/the-river-basin-management-plan-for-the-scotland river-basin-district-2015-2027.pdf http://www.sepa.org.uk/media/163445/the-river-basin-management-plan-for-the-scotland-river-basin-district-2015-2027.pdf http://www.sepa.org.uk/media/163445/the-river-basin-management-plan-for-the-scotland-river-basin-district-2015-2027.pdf Scotland’s National Water Scarcity Plan 41 Appendix 88 of the Scotland river basin management plan includes checks of whether action to address the main pressures on the water environment will also have implications on our ability to better cope with climate change. For example, measures to address the impacts of diffuse pollution such as managing inputs to land through improved soil management will also slow rainwater run-off and reduce the impacts of water scarcity and flood risk. We will continue to raise awareness of the need to adapt to climate changes and adapt our approach accordingly whilst working with others. For example we will work with water users and environmental organisations to identify areas most at risk in dry periods now and in the future so they can consider contingency planning. 8 https://www.sepa.org.uk/environment/water/river-basin-management-planning/the-current-plans/ https://www.sepa.org.uk/environment/water/river-basin-management-planning/the-current-plans/ Scotland’s National Water Scarcity Plan 42 Glossary Compensation Release: Water released from a reservoir to support a downstream river. Control Curve: An operating rule for a reservoir showing storage for each month at which certain actions need to take place. It is often used to show when abstraction from the reservoir needs to be reduced. Critical Period: The period of time a reservoir takes to empty in its driest year on record, assuming current demand. Flashy river: A river which responds very quickly to rainfall, the flow of water rising rapidly to a high peak before receding similarly. Typical of small, steep, upland catchments. Flow Percentile: The percentage of time for which a given flow is equalled or exceeded. For instance, Qn96, which is a proposed compensation figure, is the natural flow which is exceeded 96% of the time. Hands off Flow: The flow in a river at which abstraction has to cease. Multi-season reservoir: A reservoir with storage for more than one summer despite not filling in the intervening winter. Soil Moisture Deficit: A measure of soil wetness calculated by the Met Office, indicating the capacity of the soil to absorb rainfall. Scotland’s National Water Scarcity Plan 43 Annex 1 - Water saving advice There are a number of very useful sources of information for those wishing to consider water saving measures.  Scottish Water has produced a useful guide to the steps households can take to save water: https://www.scottishwater.co.uk/your-home/save-water  There are enhanced capital allowances available for some energy and water saving equipment such as rainwater harvesting systems, vehicle wash-water reclaim kit etc. The Enhanced Capital Allowances (ECAs) website is at: https://www.gov.uk/government/publications/water-efficient-enhanced-capital allowances Zero Waste Scotland provides free advice on:  Water efficiency and effluent minimisation: AND  Implementing a water minimisation programme: https://www.zerowastescotland.org.uk/content/implement-water-minimisation programme-your-business  Water, energy and resource efficiency savings: https://energy.zerowastescotland.org.uk/save-water  Waterwise have useful case studies and water saving advice at: https://waterwise.org.uk/save-water/ Good practice for irrigation UKIA provides free access to good practice guides on irrigation http://www.ukia.org/irrigationbooklets https://www.scottishwater.co.uk/your-home/save-water https://www.gov.uk/government/publications/water-efficient-enhanced-capital-allowances https://www.gov.uk/government/publications/water-efficient-enhanced-capital-allowances https://www.zerowastescotland.org.uk/content/implement-water-minimisation-programme-your-business https://www.zerowastescotland.org.uk/content/implement-water-minimisation-programme-your-business https://energy.zerowastescotland.org.uk/save-water https://waterwise.org.uk/save-water/ http://www.ukia.org/irrigationbooklets Scotland’s National Water Scarcity Plan 44 Annex 2 – Water scarcity indices In order to improve our ability to plan for and respond to water scarcity events, SEPA commissioned a study to find a methodology for measuring water scarcity severity in Scotland. The resulting analysis of historical water scarcity impacts in Scotland (Zaidman et al 2012) shows that it is departure from the norm rather than a measure of absolute water supply that determines whether water scarcity impacts occur and that suggested that a water scarcity index approach might work well. A water scarcity index is a measure of how exceptional a period of water scarcity is. SEPA’s water scarcity index can be calculated using rainfall or flow data and is calculated for 30 day, 60 day, 90 day and 180 day periods, by subtracting the logarithm of current rolling mean from the logarithm of the long term mean and dividing this by the standard deviation, as shown by the equations in the box below. Scotland’s National Water Scarcity Plan 45 Scotland’s National Water Scarcity Plan 46 For the purposes of managing agricultural water usage and river flows with little or no groundwater component, we will use an index based on the cumulative flows over the previous month. This is a good compromise between using longer term data which won’t be sensitive enough to pick up changes in sources with little or no storage and using shorter term data (e.g. daily) which would not account for the effects of continued dry weather. For reservoirs, the period used will vary according to the storage available and the ‘critical period’ (length of time a reservoir takes to empty in its driest year). Table 9: Water scarcity index Rainfall index River flow index (Cumulative rainfall) (Average flow) Condition 3 months 1 month Normal conditions <0.25 <0.25 Water scarcity early warning 0.25 0.25 Water scarcity alert 0.5 0.5 Moderate water scarcity 1.0 1.0 Significant water scarcity 2.0 2.0 Reference Zaidman MD, Anderton A, Peacock A, Kinnear J & Lamb R 2012. Development of Drought and Low Flow Indices. Report prepared by JBA consulting for SEPA project EOSRAD57. March 2012. Scotland’s National Water Scarcity Plan 47 Annex 3 – Water Saving Measures Advance planning during periods when there is plenty of water is essential to managing periods of water scarcity. A number of possible water saving measures are outlined below. Recirculation Some operators may have the potential to recirculate water depending on the specific process. Cooling water isn’t required to be of high quality and should be recycled wherever possible given the large volumes used. Altering production schedules Depending on the type of operation there may be flexibility to balance supplies within the current abstraction licence. Where water supplies are used intermittently there may be scope to amend production dates to avoid periods where the resource is under stress. Scheduling of water abstractions Simple informal water scheduling already takes place in Scotland where operators agree who can abstract on specific days. The system works well where operators can work together to maximise the collective benefit from the available resource. Management agreements A management agreement is a formal agreement between two or more operators based on the scheduling of abstractions set out above which provides a mechanism for achieving sustainable abstraction levels for all persons party to the agreement. The terms of the agreement are incorporated into the operators’ CAR authorisations, usually by variation, to formalise the arrangements for allocating water and establish limits on the quantity of water that can be abstracted from specific water bodies by each abstractor. We have authorised one management agreement and are monitoring its effectiveness with a view to expanding the approach to other catchments that are potentially at risk. Scotland’s National Water Scarcity Plan 48 Water abstraction groups Similarly water abstraction groups (WAGS) allow sharing of resource between operators; one licence is held and managed by a limited company and the company allocates resource to various abstractors. This mechanism avoids the need to vary conditions in multiple individual authorisations which is often the case when using a management agreement. WAGs can enable greater flexibility to share resource amongst a group of abstractors. Amending mitigation in CAR authorisations Dams and reservoirs often have conditions within their CAR authorisations requiring the provision of flows downstream of the impoundment (mitigating the impacts of the activity). Compensation flows are often enhanced during periods of fish migration by additional releases called freshets which mimic natural high flows. In certain cases where flows are so low elsewhere in the catchment there may be scope to amend compensation flows and freshets downstream of dams (fast track CAR) for short periods. If fish are not moving elsewhere in the catchment then delivering a freshet may cause more problems such as stranding fish. Such decisions would be taken with advice from local fishery boards and trusts and discussed with operators on a case by case basis. Alternative sources Alternative supplies from other less impacted surface water bodies or groundwaters may be possible. New supplies may have impacts on the environment or other water users therefore this should be discussed and investigated with us at the earliest opportunity to allow an assessment of the potential impacts to be undertaken. Considering storage Off-line storage ponds allow water to be abstracted during high flows to be used during periods of low flows. While ponds require a large area of land they can provide security of resource, low maintenance and additional benefits such as biodiversity and flood prevention. Scotland’s National Water Scarcity Plan 49 Funding for irrigation lagoons To improve water security and reduced impacts on the water environment in periods of low flows. https://www.ruralpayments.org/publicsite/futures/topics/all-schemes/agri-environment-climate scheme/management-options-and-capital-items/water-use-efficiency---irrigation-lagoon/ Groundwater supplies and augmentation Groundwater can provide a reliable supply of water when surface water resources are under stress. Groundwater could also be used to augment river flows when they are low either to protect valuable ecology or to top up the resource for subsequent abstraction downstream. Augmentation of surface water already happens in parts of England. https://www.ruralpayments.org/publicsite/futures/topics/all-schemes/agri-environment-climate-scheme/management-options-and-capital-items/water-use-efficiency---irrigation-lagoon/ https://www.ruralpayments.org/publicsite/futures/topics/all-schemes/agri-environment-climate-scheme/management-options-and-capital-items/water-use-efficiency---irrigation-lagoon/ Scotland’s National Water Scarcity Plan 50 Annex 4 - Clarification of criteria used to determine Significant Water Scarcity Following a review of water scarcity events during 2018 and previous years, we are updating how ‘Significant Water Scarcity’ is determined in this national plan to provide greater transparency and clarity. The revised approach takes effect in June 2020. The National Water Scarcity Plan sets out the hierarchy of action expected from those involved with water management and use, during prolonged dry periods. The slowly developing nature of these events, in comparison to flooding, allows us to take a staged approach that is proportionate to the risk to the environment and water users. As conditions worsen and reach Significant Water Scarcity we have said that temporary suspension of abstractions is required to protect the environment. We have reviewed the hydrological conditions and ecological impacts in the 2018 drought and considered these alongside other evidence. While the conditions can vary, impacts always reflect a prolonged period of dry weather. When rivers remain at low flows for an extended period they are highly sensitive to further reductions of flow and/or abstraction, with a heightened risk of severe, long-lasting ecological impact. To simplify and clarify our approach we will define Significant Water Scarcity when: The average river flows in the region concerned have remained exceptionally low for 30 days in a row. This will be defined when the five day mean flow is less than or equal to Q95 for 30 consecutive days. Explanation of terms The five day mean flow is the flow in a river averaged over a five day period. It is used to smooth out brief rises or falls in flow. These average river flows are calculated using a SEPA flow monitoring site that is representative of rivers in the region. The Q95 is a term used to describe an exceptionally low flow level. It is a flow which, on average, a river only dips below for 5% of the time. This equates to 18 separate days in any year on average. Scotland’s National Water Scarcity Plan 51 This clarification allows us to give notice to water users in at-risk catchments so contingency measures can be put in place. SEPA will continue to work with stakeholders to provide useful information as early as possible to let water users make decisions about upcoming water usage. Our Water Scarcity page (https://www.sepa.org.uk/environment/water/water-scarcity/ ) has weekly updates and the latest positions. The Drought Risk Assessment Tool (linked on water scarcity page https://www2.sepa.org.uk/drought-risk-assessment-tool ) displays which gauging stations have dropped below the Q95 level and for how many days. Abstraction licences will be grouped to the most relevant gauging station. https://www.sepa.org.uk/environment/water/water-scarcity/ https://www2.sepa.org.uk/drought-risk-assessment-tool