SESRO set to clear RAPID Gate Three despite cost escalation

(by Karma Loveday)

The Regulators’ Alliance for Progressing Infrastructure Development (RAPID) is consulting until 29 January on its draft decision that the South East Strategic Reservoir Option (SESRO) solution should pass Gate Three of its staggered approval process.

This decision would unlock £100m in funding, enabling the solution to continue refinement on its journey to Gate Four. The next stage of work includes further design development, finalising the groundwater flood risk mitigation and drainage solution, and developing the Preliminary Environmental Information Report.

RAPID listed the following key reasons for proposing to approve that the scheme passes to RAPID Gate Four:

• The £65.4m allowance for RAPID Gate Three development activities was spent efficiently – ensuring value for money for customers. 

• The depth of evidence provided regarding the programme and planning, risks and issues, and the procurement and planning strategy for the scheme was rated good overall. 

• There are clear benefits from proceeding with further development and enabling work, and this will be essential to keep to a timeline targeting a construction-ready state by 2029 (and operational from 2040).

  
  

The draft decision noted that the SESRO Gate Three submission did not present evidence concluding that the reservoir remains best value given the cost increase stated in the Gate Three submission (this is now estimated at £5.5-7.5bn capex). The solution owners – Thames, Southern and Affinity – must now use the statutory water resources planning process to update their best value decision making by 30 June 2026.