Drought Management Plan Annual Update 2019 Affinity Water November 2019 Security Notice This document has been written in compliance with our security policy so that no redaction is required for publication. Codes have been used to preserve the security of our production locations. Drought Management Plan Annual Update November 2019 Page 1 of 132 Asset Strategy document control sheet Document amendment history Version Status Date Amendment to this version V1 Draft 12/05/2017 First draft V2 Draft 14/12/2017 Amendments following public consultation Minor amendments to incorporate lessons learned from V3 Final 26/11/2018 2017/2018 drought experience and changes to draft WRMP19 Annual update to include lessons learned and align with V4 Final 29/11/2019 changes to draft final WRMP Document approval Document title Drought Management Plan Annual Update 2019 e-Document location https://stakeholder.affinitywater.co.uk/drought-management.aspx Name Signature Title Date Anneka Johnson- Senior Asset Author/originator 19/09/2019 Marshall Scientist Senior Asset Technical Reviewer Ellie Powers 28/09/2019 Manager Approver 1 HoD Head of Strategic Affie Panayiotou Planning and 07/10/2019 (internal use) Environment Approver 2 Legal Head of Legal Julie Smith 21/10/2019 (external use) Services Approver 3 AS Director of Asset Keith Gardner Strategy Data and 08/11/2019 Director Innovation Disclaimer This document has been prepared in accordance with the Affinity Water Quality System and is uncontrolled for use outside the company except for those recipients on the controlled circulation list. Uncontrolled copies will not be updated if and when changes are made. If you do not have a controlled copy and you wish to make use of this document, you should contact Affinity Water to obtain a copy of the latest available version. Drought Management Plan Annual Update November 2019 Page 2 of 128 This page is left intentionally blank Drought Management Plan Annual Update November 2019 Page 3 of 128 Executive Summary This is the Drought Management Plan (DMP) for Affinity Water and provides an update of our last DMP. This plan covers all eight of our Water Resource Zones (WRZs) across our three regions. This ensures a consistent approach to drought management is taken throughout the business and provides clarity to customers and stakeholders about the actions we would take to manage our response to a drought. Our previous annual update incorporated small changes to reflect the outcomes of our PR14 Water Resources Management Plan (WRMP), which referred mainly to our stated levels of service. The update saw the introduction of a 5th Drought Trigger Zone and a re-alignment of the actions across Drought Trigger Zones 3, 4 and 5. The full update published in 2018 then further cemented these changes and incorporated additional thinking on what this would mean in practice for the actions that we would take in the lead up to, during and after a drought. This annual update of the plan has included amendments to ensure alignment with the draft final WRMP19. It has also provided us with an opportunity to review and where necessary update our plan in light of the lessons learnt from the 2017-2019 drought and incorporates an update to our baseline environmental assessment in light of the completion of our AMP5 National Environment Programme (NEP) and AMP6 studies. As part of the development of our DMP, we have carried out scenario modelling to test our drought actions and lead-in times against a range of different drought scenarios. Droughts of different length, timing and severity were modelled to gain a full understanding of our robustness in managing these situations. Our DMP is built on our experience of managing a range of droughts over the last 30 years, in particular the multiple year groundwater droughts of 1990 to 1992, 1996 to 1998 and 2005 to 2007, as well as 2011 to 2012 and 2017 to 2019. We have a pro-active approach to managing drought and our objective is to provide secure, resilient, high quality public water supplies at all times. This will be achieved by: Being prepared for drought at any time and having our Plan ready to deal with it. Continuous monitoring of environmental conditions in partnership with the Environment Agency (EA). Identifying the onset of drought and mobilising additional resources to proactively manage risks. Assessing drought duration and severity together with the impact on water available to our customers. Minimising environmental impact of our operations during drought conditions by optimising the use of our resources. Implementing measures to reduce the demand for water or increasing capacity of our assets to maintain security of supplies. Our actions will become more concentrated as drought deepens and lengthens. Acting and communicating with our customers and other stakeholders in partnership. This Plan details the operational process that will be used to manage drought events. It provides an introduction to our supply area and water resources and demonstrates how routine hydrological data is monitored to determine the onset of a drought, the implications of which are managed by our Drought Management Group (DMG). The DMG is responsible for implementing actions to ensure public water supply is maintained through the drought. Our DMP links with the WRMP, which addresses investment issues relating to drought. Drought Management Plan Annual Update November 2019 Page 4 of 128 All droughts will vary in terms of their duration and impact on the availability of water resources. The return-to-normal conditions are unpredictable and dependent on increasing levels of rainfall/recharge, making the duration and severity of droughts difficult to forecast. We have therefore tested our DMP against a range of possible drought scenarios to ensure that the measures we propose to adopt are sufficiently robust to protect essential water supplies and minimise the environmental impact of these actions. The drought scenario testing work included modelling of drought events which are more severe than those on record. The outcomes of the work demonstrated that with our proposed drought management actions, our regions are resilient to historic drought events, including those assessed as worst historic events, in the 1930s and 1940s. This work has allowed us to validate the steps we would follow in severe drought conditions when requirements for restrictions on use of water or additional abstraction could result in the mobilisation of Temporary Use Bans (TUBs), drought orders for further demand restrictions and drought permits or drought orders to vary abstraction licences. A summary of these actions is shown in the diagram below. The Plan indicates how the severity and duration of drought is assessed and forecasted and when and how drought actions are implemented. This DMP defines individual roles and responsibilities within Affinity Water during a drought and the required levels of interaction/liaison with third parties, in particular the Environment Agency. The Plan contains details of our environmental monitoring and communication plans and the actions that would be triggered under this Plan in response to breaching the drought triggers. Finally, our Plan provides an outline of how the company will identify the end of a drought and describes the associated actions required at this point. Drought Management Plan Annual Update November 2019 Page 5 of 128 Glossary ADO Average Deployable Output – the average output of a source BMA Bulk Metered Area ALF Alleviation of Low Flow Scheme AMP Asset Management Period – 5 year investment period used AMR Automatic Meter Reading DD11 The Drought Direction 2011 DI Distribution Input – the amount of water entering the distribution system at the point of production DO Deployable Output – the output of a commissioned source or group of sources assessed under drought conditions Drought Order An authorisation granted by the Secretary of State under drought conditions which imposes restrictions upon the use of water and/or allows for abstraction/impoundment outside the schedule of existing licences on a temporary basis Drought Permit An authorisation granted by the Environment Agency under drought conditions which allows for abstraction/impoundment outside the schedule of existing licences on a temporary basis DMA District Metered Area DMP Drought Management Plan – Operational plan which sets out how the company will deal with a drought situation DTZ Drought Trigger Zone – a trigger line for groundwater levels at specific points which indicate stages at which different drought actions need to be carried out EA Environment Agency EAR Environmental Assessment Report – report to support drought permit applications, which investigates and predicts environmental impacts of permits, as well as setting out the associated monitoring and mitigation actions EP Effective Precipitation – the amount of precipitation which is actually added and stored in the soil. Used as an indicator of recharge GWL Groundwater level – level of groundwater above ordnance datum HDZ Hydraulic Demand Zone – zone characterised by having discrete supply and storage arrangements with strategic inter zone transfers HRA Habitats Regulations Assessment – an assessment of effects of actions on any Special Areas of Conservation, Special Protection areas or Ramsar sites, as per the requirements of the Habitats Regulations LSE Likely significant effects – referring to environmental impacts of certain actions LTA Long Term Average – average monthly rainfall