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Where's the water? | Capacity challenge


Water companies in England are preparing their next Water Resource Management Plans (WRMPs) – documents produced every five years as part of the regulatory Asset Management Plan (AMP) negotiations and which, until now, have looked ahead at demand for the next 25 years.

But population growth and a changing climate are this time prompting a rethink at the water industry ministry, Department for Environment, Food and Rural Affairs (Defra).

The government also wants the water companies to build up resilience across England, not just within their own boundaries. That means they will have to work together, and with government agencies such as the Environment Agency and with the private sector; sharing water; and building joint new assets. 

Water resource planning timetable

Water resource planning timetable

Water companies will be asked to “consider every option” including:

  • Collaborating with neighbouring water companies to trade or enable cascades of water, or develop joint infrastructure/connections
  • Collaborating with other sectors, such as energy and agriculture, to develop joint infrastructure, offer water services or procure water supplies
  • Enhancing the natural resilience of the catchment to increase the water available for abstraction without posing unacceptable pressures on the environment
  • Minimising leakage, reusing water and helping customers use water more efficiently.

There is some urgency from Defra. The new approach will apply for the new AMP period, starting only three years away in 2019. A new resilience section must be included in WRMPs to show how the options have been considered. The year 2019 is also the 30th anniversary of water privatisation, and as the industry reaches maturity it is being asked to reassess its priorities and its contribution to society.

Doing the numbers

According to those doing the numbers in the industry, this will likely require capital investment in new reservoirs, industrial scale reverse osmosis schemes to allow reuse of sewage water and heroic transfer projects using pipelines and canals. The investment required will be as significant as any yet seen, to provide enough resource to keep the population supplied with water.

In its Creating a great place for living; enabling resilience in the water sector published in March, Defra points out that the existing water resource planning framework has helped the water companies understand future needs and maintain the balance of supply and demand within their own boundaries. 

Water resilience

“But it has not fundamentally increased the resilience of water supplies in parts of the country, or driven a step change in how water is traded between regions,” it says.

It goes on: “As a nation, we are not managing the water available to us optimally, with some customers at greater risk of supply interruptions than they might expect.”

As a consequence, Defra has asked the water industry, led by Water UK, to develop a national resources long term planning framework looking at the next 50 years. It also wants the industry to investigate the strategic options that could be needed. These will be used to inform the WRMPs (see box). Crucially, the work will test a range of population growth, climate and environmental protection scenarios to assess the impact on water supply.

drought 1976

drought 1976

Nightmare scenario: Standpipes in the streets

“What Defra is seeking to draw out is recognition that water companies have a critical part to play in meeting the needs of the country as a whole,” says Thames Water water resource stakeholder Simon Hughes. “None of us will get economic growth, wellbeing and good quality of life unless there is enough water.”

So what are the problems? 

Arguably, the most immediate is population growth and especially population growth in the regions of Britain that are already water stretched, namely East Anglia, the South and South East,  particularly London.

Northern Powerhouse

All power to the Northern Powerhouse, which may spread economic focus in the future, but at the moment and for decades hence it is the dry South – which gets less rain than Barcelona or Jerusalem – where current growth is centred. 

London is looking at a potential 40% increase in its population by 2050.

Current figures assume a rise from 8M to 11M – the equivalent of adding the populations of Birmingham and Edinburgh to the capital. Demand for water is projected to exceed supply by 10% in 2025 and by 21% in 2040.

Urgent decisions

This means Thames Water is facing some urgent decisions.

Added to its equations is a changing climate of warmer and wetter winters, and hotter and drier summers.

Current collection and storage systems are set up for the rainfall patterns and water supply demands of the past not the future. As demand grows and rainfall polarises to a lot in winter and very little in summer, Thames Water needs to reassess. 

European legislation

It requires extra capacity to gather and store the water when it is in the system rather than letting it run away to sea, and it needs to look at additional ways of filling the supply gap in the dry season.

This also has to be planned against a background of the European Union’s Habitats & Water Framework Directive that requires more water to be left in the rivers and aquifers rather than being abstracted for water supply. The aim of this is to benefit the environment, a key part of creating the wellbeing that makes for great places to live, which is the underlying aim of the Defra paper.

“We’ve actually been really fortunate that there has been no significant failure in water resource in the South East for a long time,” Hughes points out. There was a lucky escape in 2012 when hosepipe bans got London through a dry spell, but it was 1976 when the country last saw a standpipe in the streets. In the South West, reservoirs ran dry and ministers were suggesting bath sharing as a way of saving water. 

We’ve actually been really fortunate that there has been no significant failure in water resource in the South East for a long time

Simon Hughes, Thames Water

More recently, during the floods of 2007, 500,000 people were left without water or power when a treatment works and substation were flooded. No one wants more of that.

There is also the cost of drought to consider.  

According to a report by members of the ICE’s London and South East expert water panel, a level 3 Drought Order requiring a temporary use ban that would involve cutting off car washes and fountains, for instance, would cost the capital between £4.3M and £9.5M a day or close to £300M a month. 

An Emergency Drought Order would restrict many more uses of water. This would result in, for instance, air conditioning essential for computer rooms in City and Canary Wharf offices being switched off.

Drought risk to Underground

It could also lead to the closure of the London Underground if the pressure and volume of water required for firefighting cannot be guaranteed. The cost to the capital would be between £236M and £330M a day or a staggering £7bn to £9bn a month.

It is not impossible to imagine that after a few occurrences of that situation, traders, bankers and business would be fleeing to better resourced cities on the Continent such as Frankfurt.

So what are the options in terms of demand management and increased supply, taking London as an example? 

Thames Water is currently working through a review and screening of alternatives for new supply with the help of an Option Screening Report produced for it by consultant Mott MacDonald.

In terms of supply, Thames is looking at three major options, says Hughes. 

These are:

  • A transfer scheme using a possible mixture of canals and a pipeline to bring water from the River Severn to the Thames. That, according to Hughes, “requires a deep understanding of the water impact, its effect on species and water quality as well as how we could use existing infrastructure like canals, or put a pipeline up and over the Cotswolds”.
  • Industrial scale water cleansing and re-use, potentially based at Beckton sewage treatment works, where sewage would be filtered through reverse osmosis and then mixed with raw water at Coppermills, where it would receive additional treatment to potable standard. “We need to understand what is acceptable to the public in terms of reuse and we are expecting views to be mixed. Plus, it is a high carbon, high energy process,” says Hughes.
  • A new reservoir for storing high winter flows with option sites safeguarded in Oxfordshire at Abingdon, Longworth and Chinnor. “We are looking hard at the cost benefits of building large storage,” says Hughes.

In reality, Hughes says that over the long term, the company may need a combination of all three, phased in over time as the population grows.

Planning permission for new storage has always been a hurdle and Britain’s last significant reservoir was built almost 40 years ago. 

But schemes such as a new resource to feed London could now be deemed to be Nationally Significant Infrastructure Projects under the aegis of the National Infrastructure Commission. This would allow a different, faster, planning approach. 

That would open the door to new funding options – Thames Tideway Tunnel is being privately financed and similar options could be available for new investment.

Experience tells us that people moving into houses with water efficient showers, for instance, replace them with high use power showers purchased from DIY stores

Paul Chadwick, Mott MacDonald

As Defra has indicated, managing demand will have to play a major part in future supply equations. Londoners are using 160litres/day each, 10litres/day higher than the national average, which itself needs to fall. 

“We could all use less water,” says Mott MacDonald divisional director Paul Chadwick. “As the population grows, new homes will be built, and there is an opportunity to make them water efficient using the sustainable homes code attached to the Building Regulations. 

“But experience tells us that people moving into houses with water efficient showers, for instance, replace them with high use power showers purchased from DIY stores and bathroom suppliers. There’s a need for change at a national level for better control on the sale of water efficient appliances.”

Chadwick also points to leakage control as another option for conserving water. 

Cost of leaks

“But the problem is cost. Companies have all fixed the big leaks through find and fix, mains replacement and pressure control. But there are thousands of small leaks all over London alone that evade normal leak detection methods that would require a step change in mains replacement to address, with consequent impact on water bills.

“However, the Water UK national study may demonstrate that increased investment in leakage reduction would be of best benefit to water supply, which may change the game.”

The Water Act 2014 placed a new resilience duty on industry regulator Ofwat. And Defra has also indicated that the Water UK project could encourage it to change the levels of service required from companies to make supplies more drought resilient, allowing the regulator to look more widely at the evidence to support new levels of capital spending. 

“That is where the scenario approach of the Water UK work is excellent,” Hughes says. “People will be able to see what could happen and how we could deal with it. Do we plan for the more severe options from our scenario analysis and if so, what will they cost? It’s a policy choice we can put to government and customers but in an informed way.”

Defra is due to issue guidance on water resource management planning this spring, the Water UK national study reports in the summer with a level of service direction to companies, if issued, due to be announced by Defra in the winter. The results would feed into WRMP work from 2017. Draft plans have to be submitted the following year.

Defra roadmap

The Creating a great place for living – enabling resilience in the water sector report published by Defra is a policy framework roadmap.

It sets out how the government will enhance its policy framework to account for increasing pressure on the water sector in England because of climate change and population growth.

Population in England is forecast to grow by 10M by 2050; at the same time summer temperatures are likely to increase, with rainfall decreasing, leading to an increased risk of short duration droughts.

New water resources will be needed. The roadmap sets out how Defra will enable water companies to enhance the resilience of public water supplies. It will also support those industries taking water directly from rivers and groundwater to better manage their resilience risks including through closer collaboration with water companies. The document also sets out how the department will work with Ofwat to enhance the sector’s resilience.


Regional supply solutions

Defra has asked Water UK to look at the options for balancing supply and demand between regions and to highlight options that represent best value for money over time “so they are not ignored in favour of the cheaper”.

As well as informing companies’ water resource management plans, it should provide valuable evidence for the National Infrastructure Commission to help its assessment of long term infrastructure needs.

The work involves the water companies and government agencies including Ofwat, the Environment Agency and the Drinking Water Inspectorate. It is being aided by consultants Mott MacDonald, Atkins and Nera.

The outcome of the work will provide information to Defra on which it can base a decision as to whether to issue new guidance on levels of service to one or more companies. 

Water companies will be able to use scenario options produced by the project to help consider the options. 

The scope has now been extended to include Wales with the support of the Welsh Government and the regulators.

Work includes:

  • Reporting on the capacity and connectivity of the current asset base including mapping potential transfer routes
  • Reviewing current levels of service and risk using probability based stochastic modelling rather than historic rainfall records
  • Presenting planning scenarios, options and choices over a 50-year horizon and developing potential investment options.




















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