As a Cornish MP, I have long been aware of the challenges created for our aquatic environment by storm overflows. When I became Secretary of State in February 2020, I instructed officials to change the strategic policy statement for Ofwat to give the issue greater priority.
This is the first Government to set a clear requirement for water companies to reduce the harm caused by sewage discharges: we have set that in law through the Environment Act 2021. We are taking action now on a scale never seen before. Water companies are investing £3.1 billion now to deliver 800 storm overflow improvements across England by 2025. This will deliver an average 25% reduction in discharges by 2025.
We have also increased monitoring. In 2016, only 5% of storm overflows were monitored. Following the action of this Government, almost 90% are now monitored, and by next year 100% of all storm overflows will be required to have monitors fitted. This new information has allowed our regulators to take action against water companies. The Environment Agency and Ofwat have launched the largest criminal and civil investigations into water companies ever, at more than 2,200 treatment works, following the improvements that we have made to monitoring data. That follows 54 prosecutions against water companies since 2015, securing fines of nearly £140 million.
Water companies should consider themselves on notice. We will not let them get away with illegal activity. Where permits are breached, we are taking action and bringing prosecutions. Under our landmark Environment Act, we have also made it a legal requirement for companies to provide discharge data to the Environment Agency and make it available to the public in near real time: within an hour. This is what Conservative Members have voted for: an Environment Act that will clean up our rivers and restore our water environment; that has increased monitoring and strengthened accountability; and that adds tough new duties to tackle sewage overflows for the first time.
The Government have also been clear that companies cannot profit from environmental damage, so we have provided new powers to Ofwat under the Environment Act to modify water company licence conditions. Ofwat is currently consulting on proposals that will enable it to take enforcement action against companies that do not link dividend payments to their environmental performance or that are failing to be transparent about their dividend payouts.
Yesterday, I laid before Parliament the storm overflows discharge reduction plan. The plan will start the largest investment in infrastructure ever undertaken by the water industry: an estimated £56 billion of capital investment over the next 25 years. It sets strict new targets for water companies to reduce sewage discharges.
Designated bathing waters will be the first sites to see change. By 2035, water companies must ensure that overflows affecting designated bathing waters meet strict standards to protect public health. We will also see significant reductions in discharges at 75% of high-priority sites.
Water is one of our most precious commodities. Water companies must clean up their act and bring these harmful discharges to an end. I commend our storm overflow report, which was published yesterday, to the House.