Portsmouth Water has set out details of actions it plans to take during AMP6 to mitigate climate change impacts, including the construction of new flood defences at two high risk sites and new UV disinfection works at two water treatment sites to tackle increasing risks from cryptosporidium.

The water company is also looking at automating its emergency standy generation capability and an investigation into duelling a strategically significant main.

The plans are set out in the company’s second round Climate Change Adaptation plan released by Defra last week.

Introducing the plan, Managing Director Neville Smith said the company recognised that understanding future challenges such as climate change forms an increasingly important part of the its  long term approach to planning in order to maintain current high levels of service.

The report follows on from  Portsmouth Water’s  first adaptation plan published in 2011 as part of the first round of reporting under the Climate Change Act (2008) which focused on major public infrastructure providers from the energy, transport and water sectors.

In the current second round of reporting, Defra has adopted a voluntary approach in order to provide companies with the flexibility to identify their own adaptation plans and to avoid any unnecessary duplication with existing regulation.

In addition to inviting organisations from new industries to report for the first time, companies that took part in round 1 of the report, including Portsmouth Water, were invited to provide updates on the progress of their adaptation plans submitted in 2011.

Key risks at a strategic level identified in the water company’s first report (many of which were considered to be of low risk in the short, medium or long term) - included :

• Sufficiency of water available in existing sources
• Increasing and changing demand patterns for water
• Quality of water available for abstraction
• Performance of assets Resilience of assets
• Sea level rise

The report says the action plan is reflective of the company’s asset structure. For example, the majority of the mechanical and electrical assets have an asset life of 15 years and so are frequently replaced and updated and so are not as exposed to long term climate risks. In contrast, longer life assets such as concrete service reservoir structures which may last 50+ years will require more climate change considerations in the shorter term.

Portsmouth has set out details of work it will undertake during AMP6 on energy consumption, carbon reduction, water efficiency and leakage, including increasing the proportion of electricity used from renewable sources by 10% during AMP6. The water company is also trialling a new intelligent pump management system which can bring energy savings of up to 30%, increase efficiency and reduce carbon emissions. If the trials are successful the company will consider investment in AMP7

During AMP5 flood defences were  installed at 4 high risk sites which were considered to be at a likely risk of a 1-in-100 year fluvial flood or a 1-in-200 coastal flood following a flood survey. Following a further survey, new flood defences will also be installed at 2 more high risk sites during AMP 6.

Other initiatives the company is planning to undertake include:

• Ultra Violet disinfection works to be built at two water treatment sites to mitigate the increased risk of cryptosporidium
• The company will continue to proactively work with local farmers to improve the quality of raw water in the water catchment, targeting 5 sites experiencing increasing nitrate levels
• Improvement of disinfection to meet Water Quality Standards

Cryptosporidium risk score increased

The main area where Portsmouth has identified an increased risk score is from cryptosporidium contamination - the nature of the chalk aquifer in the region means the company is vulnerable to turbidity events. The risk has been demonstrated by increased detection of cryptosporidium at two sources close to each other and both sites have experienced outages as a result.

Portsmouth Water says the likelihood scores have therefore increased and it is continuing to closely monitor and review its water quality. As a result of increased cryptosporidium detection, more sophisticated treatment will be installed at two water treatment works in AMP 6 to mitigate the current risk.

The company will also investigate duelling a strategically significant main to increase resilience in the event of a major pipe burst and conducting an investigation into the automation of standby generation. Approximately 80% of the company’s water treatment works and pumping stations have stand-by generation to provide an alternate electrical supply in the event of a power outage, 60% of which require manual intervention.

Findings of Resilience Study will drive future capital planning

The report also outlines the company’s Resilience Study project planned for AMP6 in which the findings will drive future capital planning actions. Portsmouth is proposing to appoint a consultant to undertake an Operational Resilience Study which will be a combination of a written report to identify potential areas of improvement and a strategic operational model.  Using scenarios, the model will test the network to enable the company to assess the impact on demand dependent on site outages, planned maintenance and operational events.

Need for Ofwat to define level of resilience with “clear parameters of when to invest”

The report says the project is motivated by increasing interest in resilience within the UK water industry and its regulators in recent years and includes some interesting comment on the sector’s existing regulatory framework, saying:

“The current 5 year rolling planning cycles allow for short to medium term adaptation and flexibility, however it is not as suited to long term drivers such as climate change. Capital investment requires significant justification to the regulator however the wide uncertainty of the UKCP09 does not provide this.”…

“There is also potentially a need for the regulator to define the level of resilience to climate change that water companies should meet setting clear parameters of when to invest.”

Click here to read the report in full