Research by her party has revealed the utilities firm has handed executives £2 million in pay and perks in the last financial year.
The Lib Dems are calling for a ban on all CEO bonuses within the water industry and major reform of it.
The news comes as 12,000 people in the Guildford area were left without water for two days earlier this week.
Thames Water apologised on Sunday saying Storm Ciarán had caused technical issues at its Shalford treatment works.
It’s thought 3,000 people are still reporting issues.