The leadership change comes a day after the water supplier was given the lowest environmental rating by regulators following 335 pollution incidents.
Yorkshire Water has confirmed the departure of its chief executive, just a day after the water company received the poorest environmental performance rating from the regulator.
Nicola Shaw has chosen to step down after four-and-a-half years at the helm of the organisation, the company said.
Nicola Medalova, a former National Grid executive, will arrive next week as chief executive-designate, before officially taking up the position in January.
Ms Shaw said there was “still a lot of work to do”, but the business was on a “stronger footing for delivery in all aspects of its work”.
He added: “Now seems like the right time to begin an orderly transition into the next chapter of the company.”
On Thursday, the Environment Agency (EA) announced it had downgraded Yorkshire Water’s environmental performance rating from two stars out of four to one – the lowest possible rating.
This classification means it is considered an underperformer and, along with Southern Water, Thames Water and South West Water which also received a one-star rating, is automatically prevented from awarding bonuses to senior executives under new regulations introduced last year.
The utility, which serves more than five million customers in the Yorkshire region, recorded 335 pollution incidents in 2025, including 13 categorized as serious, the EA found.
It was fined a total of £1.2 million last year for pollution incidents.
Yorkshire Water has also faced previous criticism over remuneration to Ms Shaw worth £1.3 million between 2023 and 2025 paid through Jersey-based company Kelda Holdings. The company emphasized when shareholders, rather than bill payers, had funded the payments.
Ms Medalova said: “Yorkshire Water faces huge challenges but also huge opportunities to continue to improve, and I look forward to working with Nicola Shaw, the leadership team and colleagues across the business as I step up to speed.”
They are committed to maintaining a “relentless focus” on delivering “for customers, communities and the environment”.