I would like to say to the hon. Lady that my remarks about people misinterpreting what is being done do not apply to her. She has been a doughty champion on this issue; she has led debates in this House and we have had good cross-party discussions. She makes an interesting point: there are already five-yearly reviews, but whether that should be done more frequently is an interesting question, and maybe the Minister might like to respond to it in her winding-up speech.
Moving on, the pressures on the drainage systems have been developing over six decades, as investment in water treatment infrastructure and drainage systems underground has not kept pace with development above ground, as my hon. Friend Dr Poulter has pointed out. It is also exacerbated by pollution caused by others—both farming practices, which my right hon. Friend the Member for Hereford and South Herefordshire described, and run-off from highways and other hard standing—so I accept that it is not exclusively the responsibility of water companies.
As the Secretary of State himself acknowledged before our Select Committee, the solution ultimately may require separation of surface and foul water drainage systems, and I believe the Department is currently trying to get a harder estimate of the cost of such a massive exercise. It will take enormous capital expenditure to correct the problem for good, and the work will take decades to complete, but a start needs to be made now. The SPS provides that opportunity.
I will focus my remarks now on what Ofwat should consider in its negotiations with water companies to encourage them to identify and quantify solutions. It inevitably takes time to progress solutions through the planning process before the required infrastructure construction can begin, whether through nature-based solutions or traditional mechanical and chemical systems. Much of that involves installing monitoring equipment to increase public awareness of the quality of receiving waters in real time. That was a key transparency recommendation of my private Member’s Bill and our Committee report, and it is now required to be introduced under the Environment Act. However, it merely establishes the baseline; the real spend will be incurred in the corrective measures required.
In my own constituency, Severn Trent Water has announced plans to invest £4.5 million to achieve bathing water quality status along some 15 miles of the River Teme between Knighton and Ludlow as part of their “Get River Positive” investment plan. That is obviously very welcome. The Thames Tideway tunnel will make a remarkable difference to water quality here in London. It illustrates well both the high cost and the length of time involved in delivering a transformational project to improve water quality, namely £4.9 billion and 11 years from securing planning to becoming operational respectively.