Policy paper

Appendix B: water resources modelling: National Framework for Water Resources 2025

Published 17 June 2025

Applies to England and Wales

Future water needs: national summaries

Four modelled scenarios were run as part of the National Framework. The national pressures and supply demand balance (surplus/deficit) vary significantly across each as highlighted in Figure 31. Results in text below are reported to 3 significant figures.

Figure 31: Components of the supply demand balance (surplus/deficit) in Ml/d under the four modelled scenarios of Do Nothing, High, Central and Low at 2055

These show the deficit in the total supply demand balance in the Do Nothing and High needs scenarios and a surplus in the Central and Low scenarios.

Note that Figure 31 shows only the principal drivers and does not provide a comprehensive representation of all components of the supply demand balance, such as headroom.

Do Nothing

Category	WRMP24 final plan supply demand balances in 2025
Drought measures impact on supply	0
Resource options impact on supply	0
Environmental needs impact on supply	-2,624.47
Climate change impact on supply	-344.12
Resilience impact on supply	-627.35
Leakage impact on demand	0
Non-household (NHH) growth impact on demand	0
Household (HH) population and per capita consumption (PCC) impact on demand	-992.98
Supply demand balance	-4,370

High

Category	WRMP24 final plan supply demand balances in 2025
Drought measures impact on supply	453.24
Resource options impact on supply	1,511.51
Environmental needs impact on supply	-3,083.44
Climate change impact on supply	-772.68
Resilience impact on supply	-627.35
Leakage impact on demand	232.57
NHH growth impact on demand	-209.88
HH population and PCC impact on demand	-98.99
Supply demand balance	-1,565.97

Central

Category	WRMP24 final plan supply demand balances in 2025
Drought measures impact on supply	505.04
Resource options impact on supply	1,511.51
Environmental needs impact on supply	-3,024.12
Climate change impact on supply	-255.96
Resilience impact on supply	-627.35
Leakage impact on demand	543.83
NHH growth impact on demand	375.91
HH population and PCC impact on demand	593.57
Supply demand balance	231.69

Low

Category	WRMP24 final plan supply demand balances in 2025
Drought measures impact on supply	452.41
Resource options impact on supply	1,511.51
Environmental needs impact on supply	-2,652.02
Climate change impact on supply	-162.24
Resilience impact on supply	-627.35
Leakage impact on demand	855.08
NHH growth impact on demand	515.53
HH population and PCC impact on demand	1,815.58
Supply demand balance	2,317.76

Reductions in public water supply to meet environmental needs across the modelled scenarios are taken from either WRMP24 or estimated as per National Framework 2025 (NF2) Environmental Destination planning scenarios (Phase 1) using recent actual forecast reductions. For an explanation of the development and history of the environmental destination figures please see Appendix C: Environmental Destination technical report. This explains how the figures have evolved and how our understanding of the scale of the challenge has improved. For an explanation of how supply reductions to meet environmental needs have been estimated using the latest available Environmental Destination data, please see our water resources modelling technical report.

Do Nothing scenario

The Do Nothing scenario assumes that:

• actions from 2025-2030 as outlined in water company WRMP24s are fully delivered
• no demand management and resource development after 2030
• household population, impacts to supply from environmental needs and climate; change increase as forecast under WRMP24
• population is based on 2055 WRMP24 forecasts
• PCC, non-household and leakage remain at 2030 levels
• no drought measures
• public water supply reductions to meet climate and environmental needs are as per WRMP24 at 2055

Under this scenario, the overall supply demand deficit in 2055 is 4,370 Ml/d. The drivers of this deficit are covered in the main report in section 3.2 but highlighted in Figure 14.

High water needs scenario

The High water needs scenario assumes:

• actions from 2025-2030 as outlined in water company WRMP24s are fully delivered
• worst-case climate change impacts (representative concentration pathway (RCP) emissions scenario 8.5; 3.2-5.4°C warming by 2100) and highest population increases
• that demand management options to reduce per capita consumption and leakage only meet 60% of their savings target
• non-household demand is reduced to 9% by 2050
• that supply options are delivered as per the company plans
• the highest ambition for the environment resulting in the highest reduction in public water supply to meet those environmental needs (NF2 full Environmental Destination planning scenario)

Under this scenario the supply demand deficit is reduced from the Do Nothing scenario but by 2055 still stands at 1,570 Ml/d.

The needs of the environment are still the largest driver of future public water supply needs under this scenario, driving 3,080 Ml/d of additional need nationally compared to the baseline. This is followed by impacts from climate change with 773 Ml/d of reduction of supply driving additional need. The move to 1 in 500 resilience will drive an additional 627 Ml/d of need nationally by 2055 compared to the current baseline under the High water needs scenario. There is an additional demand from household consumption of 99 Ml/d from 2030 to 2055 under the High water needs scenario. This shows that where national population growth is occurring under the highest forecast, the assumed demand management actions are not acting enough to reduce national demand.  There is a reduction in demand from non-household growth of 210 Ml/d in 2055 compared to the 2030 baseline. This is reflective of the demand management assumptions under this scenario.

Central needs scenario

The Central needs scenario assumes that:

• actions from 2025-2030 as outlined in water company WRMP24s are fully delivered
• population is based on 2055 WRMP24 forecasts
• public water supply reductions to meet intermediate climate change impacts (RCP emissions scenario 6.0; 2-3.7°C warming by 2100)
• intermediate ambition for the environment resulting in an intermediate reduction in supply to meet those environmental needs (NF2 intermediate Environmental Destination planning scenario)
• WRMP24 actions are implemented
• supply schemes are delivered
• policy targets for PCC and leakage reductions are met
• non-household demand is reduced to 15% by 2050

Under this scenario, there is not a deficit by 2055 but a supply demand surplus of 232 Ml/d. Whilst there is additional water required to meet environmental needs, climate and becoming more resilient (3,020, 256 and 627 Ml/d respectively); these needs can be met through delivery of supply schemes and demand management activities (reductions in PCC, leakage and non-household demand). This highlights what can be achieved with sustained efforts and demonstrates the need for the WRMP actions to be delivered and policy targets to be met.

There is a reduction in demand from household growth ranging under the Central water needs scenario of 594 Ml/d. This shows that whilst population growth is occurring to some degree under the Central scenario, the assumed demand management actions (to achieve 110 litres per head per day (l/h/d) by 2050) are acting to reduce demand.  There is also a reduction in demand from leakage and non-household growth of 544 Ml/d and 377 Ml/d respectively in 2055 compared to the current baseline. This is reflective of the demand management assumptions under this scenario (15% non-household and 50% leakage reduction by 2050).

Low needs scenario

The Low water needs scenario assumes:

• actions from 2025-2030 as outlined in water company WRMP24s are fully delivered
• that future demand reduction ambition is met and surpassed, with a 60% leakage reduction, 20% reduction in non-household demand and for individuals’ water use to be 100 l/h/d
• lower climate change impacts (RCP 4.5 emissions scenario; 1.7-3.2°C warming by 2100)
• lower population increases
• low ambition for environmental needs (NF2 current Environmental Destination planning scenario)
• only non-damaging drought permits or orders

Using these assumptions a Low water needs future would result in a surplus of 2,320 Ml/d nationally by 2055.

Whilst there is additional water required to meet environmental needs, climate and becoming more resilient (2,650, 162 and 627 Ml/d respectively); these needs can be met through delivery of supply schemes and demand management activities (reductions in PCC, leakage and non-household demand).

There is a reduction in demand from household growth ranging under the Low water needs scenario of 1,820 Ml/d nationally in 2055 compared to the 2030 baseline. This shows that whilst population growth is occurring to some degree under the Low water needs scenario, the assumed demand management actions are acting to reduce demand (achieving 100 l/h/d).  There is also a reduction in demand from leakage and non-household growth of 855 Ml/d and 516 Ml/d respectively nationally in 2055 compared to the baseline. This is reflective of the demand management assumptions under this scenario (20% non-household reduction and 60% leakage reduction by 2050).

Under the Low, Central and High scenarios, demand from household population growth and demand from non-household population growth assume a level of demand management has taken place, which therefore reduces the demand compared to baseline even through growth has occurred. All scenarios assume WRMP24 supply-side options are 100% delivered. Uncertainty in the delivery of resource options (including timeframes and the amount of water they provide) has the potential to be a significant risk to both national and regional deficits. 

Whilst leakage is not driving additional need nationally, there is the potential for water to be gained through the reduction of leakage. Water companies have committed to 50% leakage reduction by 2050; if the water industry were to be more ambitious and reduce leakage by 60%, this could provide up to an additional 310 Ml/d nationally.

Nationally, supply side drought measures (drought permits) and demand side drought measures (demand savings from the implementation of media campaigns and temporary use bans during a drought) can provide up to 500 Ml/d of additional water. This increases by 80 Ml/d to 400 Ml/d, if drought permits that could be considered damaging to the environment are included.

Uncertainty in modelled scenarios

The modelled scenarios also provide a way to explore the sources of uncertainty of modelled future water needs. Note that this is uncertainty within the bounds of the modelled scenarios only; uncertainty will also be found beyond the scenarios themselves.

Figure 32: Uncertainty in components of modelled future water needs

Category	PCC and household population	Non-household consumption reduction	Leakage	Climate change impact on supply	Environmental needs impact on supply	Resilience move to 0.2% annual chance of drought failure	Total
Percentage	53	10	16	12	9	0	100

The largest source of modelled uncertainty is the combined uncertainty of changes in population forecasts and per capita consumption (ranging from 100 l/h/d to 139 l/h/d) achieved by 2055, accounting for 53% of the modelled range of national future water needs. There are elements of this uncertainty that are both within and out of the industry’s control. Whilst population changes are outside of the water industry’s control, the industry has an important role in influencing its customers to reduce per capita consumption. This uncertainty highlights how imperative it is that the demand management strategies companies have committed to, are fully delivered. If population does increase above forecasts in plans, or customer behaviour doesn’t change in line with expected targets, there could be a risk to security of supply if this is not planned for. The uncertainty and range of forecasts demonstrate the need for adaptive planning, with clear monitoring plans with triggers and thresholds that set out when alterative actions would need to be taken. 

Uncertainty in leakage reduction and non-household consumption reduction, accounts for 16% and 10% of the range of uncertainty respectively. The modelled range of additional water need driven by the environmental needs and climate change on supply is relatively small (9-12%), specifically in comparison to population and per capita consumption. Note that this is the uncertainty around the environmental needs estimated impact on public water supply (the range of reduction in abstraction to meet environmental needs), not the uncertainty related to environmental flow recovery.

Across three of the four modelled scenarios, the modelling assumes delivery of all the resource development in company plans by 2055. This equates to approximately 1,500 Ml/d of water nationally. This is just under half of the water required to account for estimated environmental needs impact on supply. Uncertainty in the delivery of resource options (including timeframes and the amount of water they provide) has the potential to drive the nation further into deficit. If only 80% of resource development were to be delivered by 2055, the nation could slip further into deficit by approximately 300 Ml/d. This could be the equivalent of one or two strategic resource options.

The sources of uncertainty highlighted here emphasise the need for flexibility when it comes to water resources planning and demonstrate the benefits of adaptive planning. To enable adaptive planning, we would expect regional groups and water companies to consider a range of potential future scenarios as we have considered here, as well as pathways and alternative options to meet them. This has been covered further in Section 2.3 on adaptive planning.

Future water needs: regional summaries

The pressures facing the country differ by geography. The summaries below set out the additional water that would be needed in 2055 when compared to the current baseline (2030) under the 4 scenarios modelled for the National Framework 2025 in each of the regional water resources group geographies. Results in text below are reported to three significant figures.

For further details on the scenarios please see the summary table contained within the main National Framework document. Further information can also be found in the interactive dashboard.

Figure 33: The pressures in each region by 2055 under the Do Nothing scenario

West Country Water and Environment (WCWE)

Category	Demand from household population growth	Climate change impact on supply	Environmental needs impact on supply	Resilience move to 0.2% annual chance of drought failure	Total
Percentage	29	7	62	2	100

Water Resources West (WRW)

Category	Demand from household population growth	Climate change impact on supply	Environmental needs impact on supply	Resilience move to 0.2% annual chance of drought failure	Total
Percentage	24	9	60	7	100

Water Resources North (WReN)

Category	Demand from household population growth	Climate change impact on supply	Environmental needs impact on supply	Resilience move to 0.2% annual chance of drought failure	Total
Percentage	29	18	32	21	100

Water Resources East (WRE)

Category	Demand from household population growth	Climate change impact on supply	Environmental needs impact on supply	Resilience move to 0.2% annual chance of drought failure	Total
Percentage	23	3	58	16	100

Water Resources South East Region (WRSE)

Category	Demand from household population growth	Climate change impact on supply	Environmental needs impact on supply	Resilience move to 0.2% annual chance of drought failure	Total
Percentage	19	7	58	16	100

WRSE

The South East of England faces a deficit of up to 2,030 Ml/d by 2055 under the Do Nothing scenario. Under the High and Central water needs scenario the South East also has a deficit of 744 Ml/d and 217 Ml/d respectively by 2055.  Only under the Low water needs future is there a surplus of 757 Ml/d. This highlights that current action (as per Central scenario) does not go far enough to ensure enough water availability for the South East by 2055. This is primarily driven by reduction in supply to meet future environmental needs.

Reduction in supply to meet environmental needs is the largest driver of public water supply needs in the South East, with 1,350 Ml/d of additional water needed under a Do Nothing scenario compared to the current baseline. There is 1,370 Ml/d driven by Environmental needs under the Low scenario, 1,580 Ml/d in the Central scenario and 1,610 Ml/d of additional need compared to baseline in a High water needs future.

In the South East, demand from household population is the second biggest driver under a Do Nothing scenario, with an additional need of 424 Ml/d forecast compared to the current baseline. An additional need of 66 Ml/d driven by household consumption is also forecast under the High water needs future where only demand management only achieves 60% of their savings target, is not enough to accommodate a higher population growth scenario. There is a reduction in additional need driven by household consumption in the other scenarios, with 186 Ml/d less demand under Central scenario and 750 Ml/d reduction under Low water needs future. This shows that whilst population growth is occurring under Low and Central scenarios, the assumed demand management actions are acting to reduce overall consumption. This is not the case under the High scenario.

Reduction in supply due to future climate change impacts is a smaller driver of additional need, with a 161 Ml/d reduction in supply under the Do Nothing scenario, 161 Ml/d in a High water needs scenarios and 71 Ml/d under the Central scenario and 5 Ml/d reduction in the Low water needs scenario, compared to the current baseline.

The move to a higher resilience standard drives 377 Ml/d of additional need under all scenarios.

Demand from non-household population growth is driving no additional need by 2055 under the Do Nothing scenario as the demand is assumed to be as per 2030. Under all other scenarios there is a reduction in demand from non-household growth when compared to the baseline. This is 122, 80 and 28 Ml/d reduction in water need for non-household consumption for Low, Central and High scenarios respectively. This is reflective of the non-household demand target under those scenarios.  

Demand from leakage is driving no additional need by 2055 under the Do Nothing scenario as the demand is assumed to be as per 2030. Under all other scenarios there is a reduction in demand from leakage when compared to the baseline, ranging from 260, 146 and 33 Ml/d for Low, Central and High scenarios respectively. Whilst not driving additional need, more water can be gained through an increased ambition in reducing leakage across the South East, moving from 50 to 60% leakage reduction could provide 114 Ml/d additional water.

By 2055, no water companies in the South East plan to rely on supply side drought measures (drought permits), with no additional water provided through them. Demand side drought measures (demand savings from implementation of media campaigns and temporary use bans in drought), provide approximately 200 Ml/d, given 2050 policy targets of demand (110 l/h/d) and WRMP24 population forecasts.

The needs driven by the environment, climate and resilience across the Low and Central scenarios described above, are all met through a range of supply and demand management options, reflected in the surplus we observe.

High, Central and Low scenarios assume WRMP24 supply options are delivered, this amounts to 777 Ml/d of additional water for WRSE. Deficits are already observed in High and Central scenarios, any risks to delivery of options (including delays and so on) has the ability to increase this deficit significantly. One strategic resource option (SESRO) accounts for 40% of the water provided through delivery of supply options.

WRE

Under the Do Nothing scenario the WRE region would face a deficit of 679 Ml/d. The region is also in deficit in 2055 under both High and Central scenarios, at 360 and 91 Ml/d respectively. Under the Low water needs future only do WRE see a surplus of 262 Ml/d.

The biggest driver of additional water need under the Do Nothing, High and Central scenarios is the reduction in supply to meet environmental needs, with a figure of 415, 567 and 546 Ml/d respectively. Under the Low scenario environmental needs drives 447 Ml/d of additional need compared to baseline. Under High, Central and Low scenarios, the reduction in supply to meet environmental needs is higher than Do Nothing that reflects the WRMP reductions. Reductions in supply to meet environmental needs of the NF2 Environment Destination planning scenarios are estimated to increase from WRMP by up to 150 Ml/d.

In the East, demand from household population growth under a Do Nothing scenario shows a 165 Ml/d of additional need compared to the baseline. Under the High needs and Central needs scenarios, the additional demand from household consumption is 120 Ml/d and 7 Ml/d respectively compared with the baseline. In a Low water needs future there is a reduction from the baseline for household demand of 201 Ml/d, driven by ambitious demand management actions.  Assumed demand management actions are not enough to reduce household consumption in the High and Central scenarios. For the High scenario, this results in an additional need of 120 Ml/d, where additional demand related to the highest population forecasts exceeds demand management actions to reduce consumption (approximately 60% delivery of PCC targets).

Climate change impacts by 2055 under a Do Nothing scenario are forecast to reduce supply by 26 Ml/d. This compares to 27 Ml/d under the Low water needs scenario and 112 Ml/d reduction compared to the baseline under the High water needs scenario.

The move to a higher resilience standard drives 114 Ml/d of additional need under all scenarios.

Demand from non-household population growth is driving no additional need by 2055 under the Do Nothing scenario as the demand is assumed to be as per 2030. Under all other scenarios there is a reduction in demand from non-household growth when compared to the baseline. This is 62, 39 and 12 Ml/d reduction in water need for non-household consumption for Low, Central and High scenarios respectively. This is reflective of the non-household demand target under those scenarios.  

Demand from leakage is driving no additional need by 2055 under the Do Nothing scenario as the demand is assumed to be as per 2030. Under all other scenarios there is a reduction in demand from leakage when compared to the baseline, ranging from 104, 77 and 49 Ml/d for Low, Central and High scenarios respectively. Whilst not driving additional need, more water can be gained through an increased ambition in reducing leakage across the East, moving from 50 to 60% leakage reduction could provide 28 Ml/d additional water.

By 2055, no water companies in the East plan to rely on supply side drought measures (drought permits), with no additional water provided through them. Demand side drought measures (demand savings from implementation of media campaigns and temporary use bans in drought), provide approximately 30 Ml/d, given 2050 policy targets of demand (110 l/h/d) and WRMP24 population forecasts.

The additional needs driven by the environment, climate, resilience and in some cases, household demand, across the Low, Central and High scenarios described above, are all met through a range of supply and demand management options, reflected in the surplus we observe.

High, Central and Low scenarios assume WRMP24 supply options are delivered, this amounts to 347 Ml/d of additional water for WRE. Deficits are already observed in High and Central scenarios, any risks to delivery of options (including delays and so on) has the ability to increase this deficit significantly. One strategic resource option (South Lincolnshire Reservoir) accounts for 49% of the water provided through delivery of supply options.

WRW

Under the Do Nothing scenario the WRW region would face a deficit of 1070 Ml/d. The West region also has a deficit in 2055 under the High water needs scenario of 340 Ml/d.

The region is in surplus in 2055 under all the other scenarios, with a difference from the baseline of 287 Ml/d under the Central scenario, and 705 Ml/d in a Low water needs future.

The biggest driver of the WRW deficit under the Do Nothing scenario is the reduction in supply to meet the needs of the environment, driving 572 Ml/d of demand by 2055. Under the Low scenario environmental needs are driving an additional 572 Ml/d of additional need, under the Central and High scenarios this figure is 603 Ml/d of additional need.

Climate change impacts in the West region result in a reduction of deployable output of 84 Ml/d under the Do Nothing scenario, 86 Ml/d under the Central scenario, 78 Ml/d in the Low water needs future and 276 Ml/d in the High water needs scenario.

Additional demand from household population growth is 233 Ml/d in 2055 under the Do Nothing scenario. Under all other scenarios, there is a reduction in household consumption ranging from 108 Ml/d for the High scenario to 544 Ml/d for the Low scenario. This shows that whilst population growth is occurring to some degree under High, Low and Central scenarios, the assumed demand management actions are acting to reduce overall household consumption.

The move to a higher resilience standard drives 62 Ml/d of additional water need in WRW under all scenarios compared to baseline.

Demand from non-household population growth is driving no additional need by 2055 under the Do Nothing scenario as the demand is assumed to be as per 2030 baseline. Under all other scenarios there is a reduction in demand from non-household growth when compared to the baseline. This is 183, 140 and 89 Ml/d reduction in water need for non-household consumption for Low, Central and High scenarios respectively. This is reflective of the non-household demand target under those scenarios.  

Demand from leakage is driving no additional need by 2055 under the Do Nothing scenario as the demand is assumed to be as per 2030. Under all other scenarios there is a reduction in demand from leakage when compared to the baseline, ranging from 342, 232 and 121 Ml/d for Low, Central and High scenarios respectively. Whilst not driving additional need, more water can be gained through an increased ambition in reducing leakage across WRW, moving from 50 to 60% leakage reduction could provide 110 Ml/d additional water.

The additional needs driven by the environment, climate and resilience across the Low, Central and High scenarios described above, are all met through a range of supply and demand management options, reflected in the surplus we observe.

High, Central and Low scenarios assume WRMP24 supply options are delivered, this amounts to 238 Ml/d of additional water for the WRW. Deficits are already observed in the High scenario, any risks to delivery of options (including delays and so on) could increase this deficit significantly.

Water companies in the West plan to use supply-side drought measures (drought permits), providing 107 Ml/ld at 2055. This reduces to 27 Ml/d if drought permits that are considered to be damaging are excluded.  Demand side drought measures (demand savings from implementation of media campaigns and temporary use bans in drought), provide 107Ml/d, given 2050 policy targets of demand (110 l/h/d) and WRMP24 population forecasts.

WReN

Under the Do Nothing scenario the WReN region would face a deficit of 345 Ml/d. A deficit is also observed under the High water needs scenario of 94 Ml/d. This highlights the significance of full delivery of demand management commitments in current WRMPs, given uncertainties in climate and environmental needs. The region is in surplus in 2055 under Central and Low scenarios, at 209 and 462 Ml/d surplus respectively.  

Under the Do Nothing scenario the biggest driver of the deficit compared to the current baseline is environmental needs, although this is equivalent to the additional needs driven by household population growth (100-110 Ml/d).

Reduction in supply to meet environmental needs are driving an additional 110 Ml/d of demand compared to the current baseline under the Do Nothing scenario. This ranges from 117 to 128 Ml/d across the other scenarios. 

Climate change impacts reduce supply by 60 Ml/d under the Do Nothing scenario, 55 Ml/d in the low water needs future, 60 Ml/d in the Central scenario and 200 Ml/d in the High water needs scenario.

Demand from household population growth results in an increase of 99 Ml/d of additional need by 2055 in the Do Nothing scenario. Demand from household consumption results in an increase of 42 Ml/d of additional need by 2055 under the High scenario, driven by a higher PCC of 120l/h/d. Under the other scenarios, household consumption reduces (range in reduction from 49 to 225 Ml/d) compared to baseline. This shows that whilst population growth is occurring to varying levels under High, Low and Central scenarios, the assumed demand management actions are acting to reduce overall household consumption.

The move to a higher resilience standard drives 70 Ml/d of additional need in WReN under all scenarios.

Demand from non-household population growth is driving no additional need by 2055 under the Do Nothing scenario as the demand is assumed to be as per 2030 baseline. Under all other scenarios there is a reduction in demand from non-household growth when compared to the baseline. This is 106, 84 and 57 Ml/d reduction in water need for non-household consumption for Low, Central and High scenarios respectively. This is reflective of the non-household demand target under those scenarios.  

Demand from leakage is driving no additional need by 2055 under the Do Nothing scenario as the demand is assumed to be as per 2030. Under all other scenarios there is a reduction in demand from leakage when compared to the baseline, ranging from 145, 99 and 54 Ml/d for Low, Central and High scenarios respectively. Whilst not driving additional need, more water can be gained through an increased ambition in reducing leakage across WReN, moving from 50 to 60% leakage reduction could provide 46 Ml/d additional water.

The additional needs at 2055 driven by the environment, climate and resilience across the Low, Central and High scenarios described above, are all met through a range of supply and demand management options, reflected in the surplus we observe.

High, Central and Low scenarios assume WRMP24 supply options are delivered, this amounts to 67 Ml/d of additional water for WReN.

By 2055, no water companies in the North plan to rely on supply side drought measures (drought permits), with no additional water provided through them. Demand side drought measures (demand savings from implementation of media campaigns and temporary use bans in drought), provide approximately 36 Ml/d, given 2050 policy targets of demand (110 l/h/d) and WRMP24 population forecasts.

WCWE

Under the Do Nothing scenario the WCWE region would face a deficit of 260 Ml/d.

The region is in surplus in 2055 under all the other scenarios, ranging from 42 to 285 Ml/d.

The biggest driver of the deficit in the Do Nothing scenarios by 2055 for the West Country is the needs of the environment driving 182 Ml/d of demand. The reduction in supply to meet environmental needs ranges from 150 to 172 Ml/d across the other scenarios.

Climate change impacts reduce supply by 19 Ml/d under the Do Nothing scenario; ranging from a reduction in supply of 12 to 39 Ml/d across all other scenarios. 

Demand from household population growth results in an increase of 85 Ml/d of additional need by 2055 in the Do Nothing scenario. Household consumption decreases by 2055 in all other scenarios, ranging from a reduction of 45 to 162 Ml/d. This shows that whilst population growth is still occurring under High, Low and Central scenarios, the assumed demand management actions are acting to reduce consumption.

Non-household consumption is reduced by 2055 across all scenarios in WCWE, ranging from 37 to 67 Ml/d of reduction in non-household demand. This is reflective of the demand management assumptions under those scenarios.  

Demand from leakage is driving no additional need by 2055 under the Do Nothing scenario as the demand is assumed to be as per 2030. Under all other scenarios there is a reduction in demand from leakage when compared to the baseline, ranging from 73, 48 and 23 Ml/d for Low, Central and High scenarios respectively. Whilst not driving additional need, more water can be gained through an increased ambition in reducing leakage across WCWE, moving from 50 to 60% leakage reduction could provide 25 Ml/d additional water.

The move to a higher resilience standard drives 5 Ml/d of additional need in WCWE under all scenarios.

The additional needs at 2055, driven by the environment, climate, resilience, household and non-household demand across the Low, Central and High scenarios described above, are all met through a range of supply and demand management options, reflected in the surplus we observe.

High, Central and Low scenarios assume WRMP24 supply options are delivered, this amounts to 83 Ml/d of additional water for WCWE. Given only a surplus of 25 Ml/d in the High water needs scenario, there is a risk that any uncertainty around supply options delivery (including timing or magnitude) has the potential to cause deficits under a scenario where demand management options only achieve 60% of their targets.

By 2055, water companies in the West Country plan only rely on 2 Ml/d of additional water through supply side drought measures (drought permits). Demand side drought measures (demand savings from implementation of media campaigns and temporary use bans in drought), provide approximately 32 Ml/d, given 2050 policy targets of demand (110 l/h/d) and WRMP24 population forecasts.

Tables showing the change from baseline in the additional public water supply needed under each pressure and each scenario for the 5 regional groups

HH consumption, NHH consumption and leakage are multiplied by -1 so that each driver is using the same scale.

Positive numbers show an increase from the baseline.

Negative numbers show a decrease from baseline. Of these, values marked with:

• ‘C’ contribute to an overall deficit under that region or scenario
• ‘DNC’ do not contribute to an overall deficit under that region or scenario

Do Nothing scenario

	HH consumption (Ml/d)	NHH consumption (Ml/d)	Leakage (Ml/d)	Resilience impact (Ml/d)	Climate change impacts (Ml/d)	Environmental needs (Ml/d)
National	-993 [C]	0	0	-627.4 [C]	-344.1 [C]	-2,624.5 [C]
WRE	-165.3 [C]	0	0	-113.5 [C]	-25.8 [C]	-415.2 [C]
WRSE	-423.9 [C]	0	0	-376.6 [C]	-160.8 [C]	-1,346.3 [C]
WCWE	-84.6 [C]	0	0	-5.1 [C]	-19.5 [C]	-181.7 [C]
WRW	-232.4 [C]	0	0	-61.7 [C]	-84.4 [C]	-572.2 [C]
WReN	-99.1 [C]	0	0	-70.4 [C]	-59.7 [C]	-109 [C]

Low scenario

	HH consumption (Ml/d)	NHH consumption (Ml/d)	Leakage (Ml/d)	Resilience impact (Ml/d)	Climate change impacts (Ml/d)	Environmental needs (Ml/d)
National	1815.6	515.5	855.1	-627.4 [DNC]	-162.2 [DNC]	-2,652 [DNC]
WRE	201	61.5	104.4	-113.5 [DNC]	-27.2 [DNC]	-447.4 [DNC]
WRSE	749.4	121.8	259.5	-376.6 [DNC]	4.7	-1,366.8 [DNC]
WCWE	161.9	66.8	73.1	-5.1 [DNC]	-12.4 [DNC]	-149.5 [DNC]
WRW	543.5	182.5	342.3	-61.7 [DNC]	-78 [DNC]	-571.6 [DNC]
WReN	224.9	-106.3	145.3	-70.4 [DNC]	-55.4 [DNC]	-116.8 [DNC]

Central scenario

	HH consumption (Ml/d)	NHH consumption (Ml/d)	Leakage (Ml/d)	Resilience impact (Ml/d)	Climate change impacts (Ml/d)	Environmental needs (Ml/d)
National	593.6	375.9	543.8	-627.4 [DNC]	-256 [DNC]	-3,024.1 [DNC]
WRE	-6.7 [C]	38.6	76.6	-113.5 [C]	-28.9 [C]	-546.4 [C]
WRSE	185.8	79.1	146.1	-376.6 [C]	-70.7 [C]	-1,577.8 [C]
WCWE	99.4	53	48.1	-5.1 [DNC]	-17.5 [DNC]	-171.6 [DNC]
WRW	310	139.9	231.7	-61.7 [DNC]	-85.5 [DNC]	-602.7 [DNC]
WReN	48.6	84	99.4	-70.4 [DNC]	-59.7 [DNC]	-125.7 [DNC]

High scenario

	HH consumption (Ml/d)	NHH consumption (Ml/d)	Leakage (Ml/d)	Resilience impact (Ml/d)	Climate change impacts (Ml/d)	Environmental needs (Ml/d)
National	-99 [C]	-209.9 [C]	232.6	-627.4 [C]	-772.7 [C]	-3083.4 [C]
WRE	-120.5 [C]	11.3	48.8	-113.5 [C]	-111.5 [C]	-567.0 [C]
WRSE	-65.6 [C]	27.8	32.8	-376.6 [C]	-160.8 [C]	-1613.4 [C]
WCWE	44.9	36.5	23.1	-5.1 [DNC]	-39.1 [DNC]	-172.3 [DNC]
WRW	108.3	88.8	121.1	-61.7 [DNC]	-275.7 [DNC]	-602.7 [DNC]
WReN	-42.2 [C]	57.3	53.5	-70.4 [C]	-198.8 [C]	-128.1 [C]