Ofwat has responded to Defra’s Improving Surface Water Drainage consultation as part of the Government’s water strategy, Future Water.  In a letter to Chris de Grouchy, Head of Flood Management ar Defra, Ofwat emphasised three key themes that run through its response.

The role of local authorities

Ofwat believes that local authorities are the most appropriate body to take the lead on producing Surface Water Management Plans (SWMP) and to take responsibility for the adoption and management of many sustainable drainage features.  In Ofwat’s view, their role in planning and managing the built environment puts them in the ideal position for these roles and best placed to play the 'integrating role' in delivering integrated urban drainage.  Ofwat believes that SWMPs should be produced on a voluntary basis but the regulator expressed its concern that SWMPs might be used as a means of 'mandating' particular investments by sewerage companies.  According to Ofwat local authorities must however have the right skills to carry out the role and commented that many lost their drainage expertise when teams were transferred to water companies.

Ofwat also commented on the need for greater clarity and definition around the expectations for water companies’ roles in providing data and expertise to support the development of SWMPs and said they should not become a default contractor or provider of last resort, as this could impose significant and inappropriate costs on water customers.

Keeping surface water out of serwers

Ofwat regards keeping surface water out of the sewers as vital in the context of a long-term need to adapt drainage systems as the climate changes, with a need to retain a clear policy focus on managing the amount of surface water entering the piped sewer network in order to reduce the likelihood of flooding.  According to the regulator, underground drainage networks will always have a finite capacity, so there will always be a need to plan and manage 'exceedance'.

The regulator commented that the automatic right to connect surface water drainage of new developments to the sewerage system should be removed, including connections to existing surface water sewers. In Ofwat’s view as much surface water as reasonably practicable should be managed by sustainable drainage solutions, then as much water as reasonably practicable should be dealt with by directly draining to a water course. Only after these options have been exhausted should a connection to a sewer be pursued.

The need for clear roles and responsibilities

Ofwat emphasised the need for clear roles and responsibilities and sees integrated solutions which involve a number of parties as important for the delivery of wider use of appropriate and innovative sustainable drainage systems.  However, it appears that Ofwat has no desire to see the Environment Agency taking over-arching responsibility for surface water drainage.  In Ofwat’s view, while the Environment Agency has a role to play in promoting good practice and sees an advisory role for the Agency in producing SWMPs as a good fit with its role in the strategic overview of inland flooding, the regulator was cautious about a potential sole responsibility.   Ofwat said

“..it is not clear how they, or any other body, could resolve any disagreement about the course of action to take to clarify responsibility and 'direct resources'.

“We need to be cautious about attempting to force integration by simplistically loading responsibilities (e.g. for all sustainable drainage features) onto a single body. “

The full response is available from the Ofwat website.