The WA Opposition says taxpayers have been ripped off by the $10.4 million sale of a division of the Water Corporation.

The state-owned water body sold its construction and engineering division was sold for $10.4 million, but the Government says it was left with just $2 million for the deal after expenses.

According to documents filed with the stock exchange by the buyer RCR Tomlinson, the Water Corporation has $130 million in guaranteed work lined up over the next three years.

As part of the deal, RCR was granted selected bidder status on Water Corporation works for two years, with the option to extend.

Water Corporation chair Eva Skira was a director of RCR Tomlinson right up until the decision to make the sale.

WA Labor water spokesman Dave Kelly is unhappy with the whole thing.

“The Water Corporation paid out $7.4 million in consultant's fees and in redundancies,” he said.

“There will be a further tax bill of almost $1 million, leaving precious little for the taxpayer out of the $10.4 million sale price.

“What was in it for the taxpayers to sell this asset for such a small amount of money?

“And then have to purchase the services of that asset back from the private company.”

Water Minster Mia Davies was forced to defend the deal.

“It wasn't done on the basis of making a return, it was made around an operational decision by the board, to manage the workflow for the ECS [Engineering and Construction Services] going forward, and how best placed they would be to respond to a changing population growth projection,” she said.

“They were either looking at making people redundant, or they were looking at trying to find ongoing employment for a majority of employees which is what happened.”