Write a drought plan

How to write a water company drought plan.

What to include in your drought plan

Your plan should include how you’ll deal with a range of droughts including long duration and very low rainfall relative to expected conditions in your water resource zones (WRZs). You should at least plan to be able to provide supplies through a repeat of historic droughts in your company records. However we strongly encourage you to plan for drought events that are of longer duration and lower rainfall than those in the historic record. If you choose not to, you should explain why.

You should understand what drought events your supply system is vulnerable to and what the probability of such an event occurring is.

If you need additional options, which are not included in your current water resources management plan (WRMP) to deal with droughts worse than recorded, make a case for them in your drought plan and include them as resilience options in your next WRMP.

You don’t need to say what you would do during a civil emergency as this is covered by your emergency plan. But you should set out the full range of actions that you’ll use up to this point.

Your drought plan should set out:

Maps you should include

Your drought plan should also include maps showing:

  • the management areas and WRZs you use
  • the alternative resources you can use during a drought, for example bulk transfers
  • the location of all potential drought permit and drought order sites
  • important ecological sites that your actions may affect, for example designated and non-designated sites of conservation importance

What else you should consider

Your drought plan should also include:

  • any data exchange arrangements you’ve made with the Environment Agency or Natural Resources Wales
  • any consultations you’ve carried out with other water companies and a statement of how you’ve taken these into account
  • any agreements you’ve made with other water companies about bulk supplies, transfers of water or division of shared resources
  • how you’ve tested your drought plan against different drought scenarios – test scenarios should differ in severity, location and length and where possible be related to those used in your WRMP
  • how you’ve produced the drought events you’ll use in your scenarios
  • information on how you’ll mitigate reductions in supply to fixed fire hydrants as a result of your actions, for example pressure reduction

What to include with your plan

You should also:

  • produce a non-technical summary of the drought plan
  • present detailed technical information as an appendix

Check your plan is consistent with other plans and can be published

You must make sure that your drought plan is consistent with other plans, including:

  • WRMPs
  • business plans
  • emergency plans
  • drought plans by the Environment Agency or Natural Resources Wales

You must consider whether any information is commercially confidential or a risk to national security before including it in your plan.

Identify drought triggers

Drought triggers help you identify when you need to take action at all stages during a drought, from its onset to its end. Your drought plan should include your chosen drought triggers and the actions connected with each one.

Drought triggers you can use on their own or in combination with each other are:

  • rainfall levels
  • reservoir volume
  • river flows
  • groundwater levels
  • any other appropriate measures

You should explain why you’ve chosen your drought triggers.

You should choose drought triggers at 1 of these 4 levels:

  1. drought management zones
  2. individual WRZs
  3. groups of resource zones
  4. your company as a whole

You should say which of these 4 levels you’ve chosen and explain why you’ve chosen it. Different triggers might apply in different areas, depending on the situation. Include a map in your plan if you need to make separate decisions about triggers in different areas.

Where necessary you should also include control curve diagrams to show your chosen triggers and levels of operation. Control curves display what level of operation a company should be in based on how much water is available and the time of the year. For example, level 1 might be normal operations whilst level 4 might be all supply side drought actions.

You should allow enough time in your plan to prepare for and carry out the actions associated with each trigger, for example applying for a drought permit or drought order or introducing water restrictions.

You should also show that your drought triggers are consistent with your WRMP where appropriate.

Test your drought triggers and proposed actions

You should use tests to prove your chosen triggers are appropriate to a range of droughts. Your tests should:

  • identify how well your drought triggers would work in different drought scenarios
  • identify what actions you’d take in different scenarios
  • assess what the effects of past droughts would be and what actions you’d take if they occurred today

Tests should cover drought lengths that are:

  • short-term, one-season droughts – typically 6 to 12 months
  • medium-term, multi-seasonal droughts – 1 to 2 years, typically consisting of 2 dry summers and a dry winter
  • long-term droughts – typically lasting more than 2 years

You should explain what relevant data you’ve used to derive the conditions for each of your tests. This should include historic data (for example, worst drought on record) and any data you may have had to produce through statistical simulation or collect indirectly (for example, from similar catchments).

Your drought plan should:

  • describe the timeline leading up to your scenarios, for example what combination of drought triggers initiated the drought and when each were triggered
  • provide details of the duration and rainfall deficit of the scenarios used in your tests
  • justify why you chose these scenarios, explaining why they were appropriate for a particular area
  • show how you’ve used the tests to develop drought triggers
  • explain what actions you’d take for each scenario
  • confirm that these actions are consistent with your WRMP

You should revise your drought scenario tests every time you review a drought plan to make sure the most up to date data are included.

Set out what you’ll do during a drought

You must clearly and concisely set out everything you plan to do during a drought.

Say how you’ll reduce demand

Your drought plan must set out what you’ll do to reduce demand for water during a drought. For example you could:

  • promote extra water efficiency
  • encourage voluntary reduction of non-essential water use
  • carry out initiatives to improve household water efficiency
  • reduce mains pressure
  • increase active leakage control
  • temporarily restrict water use
  • restrict non-essential uses of water using a drought order

Summarise what you’ll do to reduce demand in a table in this format. Include any other information needed to demonstrate and justify each of your actions along with how your actions fit in with your communications plan.

How you’ll reduce demand Action 1 Action 2
What action you’ll take, for example increase active leakage control    
Trigger for this action (or the preceding action that leads to this action)    
Saving in demand (in megalitres per day, unless stated otherwise)    
Saving in demand (% reduction on peak weekly demand)    
Location (the area affected or the whole supply zone)    
Implementation timetable (time from trigger to implementation, time of year and duration of actions)    
Any permissions needed or constraints that apply (include details of any contact you’ll have with bodies responsible for giving permits or approvals)    
Risks associated with the action, for example effects on the environment, social and economic factors and uncertainties associated with timing, quantity, quality or cost    

Usually the most efficient way to reduce water demand is to carry out your actions across your company as a whole. You shouldn’t need to reduce demand in areas smaller than WRZs.

Restrict water use temporarily

Your plan must explain how you’ll temporarily restrict water use during a drought. For example you could explain:

  • the temporary restrictions you plan to carry out (for example drought orders), including the order in which they’ll be carried out
  • how you’ll comply with the Water Use (Temporary Bans) Order 2010
  • potential exemptions and concessions
  • how you’ll balance water savings against adverse effects on customers and businesses
  • how much time you’ll set aside for comment during the consultation period before using a restriction and how you’ll deal with an unexpectedly large response
  • how you’ll tell customers, neighbouring companies and interest groups about the introduction, phasing in and lifting of temporary restrictions and how you’ll keep this information up to date
  • how you’ll prove to customers, partners and the government that you’ve acted in a proportionate and reasonable way

You should consult the UK Water Industry Research (UKWIR) report ‘Code of Practice and Guidance on Water Use Restrictions’ when considering how to temporarily restrict water use.

Estimate water savings you can make

Your drought plan should explain how you arrived at your estimates for reductions in water demand. You should specify where your information comes from and highlight any uncertainties you have about your estimates.

Further advice on reducing demand

When it is appropriate you can use the UKWIR publications to help you reduce demand and understand the savings you’ll make. These publication titles include:

  • estimating the water savings for baseline water efficiency activities
  • drought and demand: modelling the impact of restrictions on demand during drought
  • drought and demand: potential for improving the management of future drought
  • understanding the impacts of drought restrictions
  • drought demand modelling - for a copy of this contact the Environment Agency by phone on 03708 506 506 (call charges apply) or email

Include how you’ll maintain supply during a drought

Your drought plan must set out what you’ll do to maintain water supply during a drought. For example, you could:

  • recommission unused sources of water that you still have licences for
  • transfer water in bulk from other water companies or other WRZs
  • use alternative sources, for example satellite boreholes that you have licences for
  • lower pumps or deepen boreholes
  • carry out engineering work, for example increase water treatment works or the distribution network capacity
  • use other options – either temporary or permanent engineering works, for example desalination or tankering by lorries
  • use drought permits and orders
  • reschedule planned works to avoid outage

In order to demonstrate that your actions are appropriate you should:

  • estimate how much each of your actions will contribute to maintaining water supply and say how you arrived at this estimate
  • make sure your actions are consistent with the drought plans of any other water companies they affect
  • set out the limits to the amount of water you can transfer from other companies

You don’t need to say what you would do to maintain supply during a civil emergency caused by a water shortage as this will be covered by your emergency plan.

Summarise what you’ll do in a table in this format. Include any other information needed to illustrate your actions.

How you’ll maintain supply Action 1 Action 2
What action you’ll take (for example carry out engineering work)    
Trigger for this action (or the preceding action that leads to this action)    
Deployable output or yield of the action (in megalitres per day, unless stated otherwise), plus how you calculated it    
Location (area affected or the whole supply zone)    
Implementation timetable (time from trigger to implementation, time of year and duration)    
Any permissions you need or constraints that apply (include details of any contact you’ll have with bodies responsible for giving permits or approvals)    
Risks associated with this action (for example effects on the environment, social and economic factors and uncertainties associated with timing, quantity, quality or cost)    

If your actions in a drought lead to infrastructure improvements that permanently increase water output, you should state this in the ‘deployable output yield assessment’ of your WRMP.

Include details of drought permits and orders

Drought permits and drought orders allow you to increase water supplies during a drought. Drought orders can also be used to restrict use of water. Your drought plan must include details of all the drought permits and orders you might apply for under the full range of drought that you’ve planned for.

Drought permits and orders are not for managing resources during natural disasters (for example flooding) or other emergencies (for example mismanagement or other infrastructure damaging events).

For each permit or order in your plan you should provide:

  • details of what you’ll do to reduce demand for water before you apply for a permit or order
  • an environmental assessment showing the likely effects of the permit or order on the environment
  • how you’ll monitor potential environmental impacts (set these out in your environmental monitoring plan)
  • how you’ll provide mitigation or compensate for any adverse effects
  • an assessment of the rainfall patterns that could cause the drought permit or order being required

You must also be able to justify why a permit or order is the most appropriate action if there are alternatives, for example reactivating mothballed abstraction points.

You should carry out as much preparation work as possible in advance of a drought event. Applications for drought permits and orders should, where possible, be ready to submit before they’re needed. You should regularly assess and update the information held in these applications to keep them current, for example when you review your drought plan every year. This will help process your permit application more quickly and identify any problems in advance.

Say how you’ll communicate during a drought

Your drought plan should include a plan of how you’ll communicate with customers, partners and other interested groups during a drought.

Your communications plan should identify how you’ll:

  • increase customer awareness of the limited availability of water during a drought
  • keep customers, regulators and relevant organisations, for example local resilience forums, fire and rescue services and power plant operators, up to date about how a drought is developing, what you’re doing to manage it and how it might affect their supply
  • encourage customers to help during a drought by being more water efficient
  • work with interested groups and partners to reduce demand for water during a drought

When planning communications with your customers you should consider the conclusions of the Consumer Council for Water’s report ‘Understanding drought and resilience’.

Your plan should also set out:

  • how your proposed communications activities are linked to drought triggers
  • how you’ll make sure these activities are cost efficient for your customers
  • how you’ll promote the positive work you’re doing to manage the drought
  • what information you’ve agreed to exchange with the Environment Agency or Natural Resources Wales during a drought – you should agree this during preliminary discussions before preparing your draft drought plan
  • the different audiences that specific communications apply to, the main messages for these audiences and how you’ll tailor and communicate your activities to each audience

You should also:

  • pay particular attention to communicating with customers about temporary water use restrictions or bans on non-essential use
  • consider how much time you’ll need to carry out communications around increasing supply or controlling demand
  • make sure your communications plan is consistent with your emergency plan - you may need to carry out additional communications activities to deal with emergency water supply situations and emergency drought orders

If the drought affects other water companies, you should work with them and the Environment Agency or Natural Resources Wales to share information and develop joint communications activities.

When you’re planning your communications activities, you should consider the findings in the UKWIR report ‘Drought and demand: potential for improving the management of future drought

You should monitor and evaluate the effectiveness of your communications activities during a drought, for example through customer feedback, website traffic or a change in demand for water.

Your communications lead and management structure

Your drought plan should set out the management structure you’ll put in place during a drought. You should include a communications lead who will be in charge of carrying out the activities described in the communications plan.

Other suggested roles within a drought management structure include a:

  • drought manager
  • public relations lead
  • customer services representative
  • technical staff

Include details of individual roles and responsibilities and any changes to the structure as a result of a worsening drought.

You should also describe any management actions that are linked to drought triggers, for example how often the drought management team meets.

State what you plan to do after a drought

Your drought plan should set out:

  • the triggers you’ll use to identify the end of a drought
  • how you’ll review the processes you’ve followed during a drought

A drought ends when:

  • risks to the security of supply and environment from drought are no greater than they would be during a normal year
  • normal conditions have resumed for a specified period of time

You should use several indicators to determine that a drought has ended. You can also use modelling to assess if there’s still a risk from drought.

You should only declare the end of a drought after confirming with the Environment Agency and Natural Resources Wales that the water resource situation has returned to normal.

Your drought plan should set out:

  • your process for stopping your drought management actions
  • how you’ll communicate this information to customers

Review your plan performance after a drought

Your drought plan should set out what you’ll do to review your performance during and directly after a drought. You should identify in your plan what you’ll release as a result of the review (for example a ‘lessons identified’ report) and give a clear timetable for the completion of these. Include any relevant milestones (for example, data gathering stage or report writing stage).

You may need to review your drought plan, environmental assessments or monitoring plan based on this assessment. You’ll need to understand:

  • how successful, effective and cost efficient your drought management actions are (including the effects of restrictions to water use)
  • the environmental effects of your drought management actions (monitoring data before, during and after a drought and appropriate analytical techniques)
  • how effective any mitigation measures you carried out were
  • whether your estimates of reductions in water demand matched actual reductions

If the environment is taking longer than expected to recover after the drought has ended, you should undertake staged reviews to reflect this delay.

You may also need to use the results of your review to update your WRMP where relevant. You’ll need to understand:

  • what actions are needed to maintain the sources you used during the drought, for example investing in them or reassessing yields
  • whether the drought triggers were effective at identifying when to implement actions
  • if your demand management strategy needs revision following the drought
  • whether any investments you made as a result of the drought will affect other plans or programmes

During your review, state how you’ll work with the Environment Agency or Natural Resources Wales and any other people or organisations involved in the drought.

Published 20 July 2015
Last updated 7 December 2015 + show all updates
  1. Changes include: asking companies to look at a range of drought events, including a strong recommendation to consider plausible droughts beyond the worst drought on record and explain why if they haven’t; asking companies to consider the necessity for resilience options for events beyond what their supply system is capable of; clarification of our expectations for environmental assessment, mitigation and compensation (particularly with reference to what should happen at each stage ie before, during and after a drought); clarification of our expectations for companies to supply information on proposed drought permits and orders; clarification of what we expect in a monitoring plan; addition or update of links to the latest research or resources; other changes to update wording or references for clarity or to reflect policy and legislative change (ie move from 3.5 year cycle to 5 year cycle).

  2. First published.