Water Corporation in Western Australia will shed hundreds of jobs, as it shifts its corporate direction.

The State Government has confirmed that Water Corporation’s workforce will be reduced by 10 per cent, or about 300 workers.

The redundancies come from a shift at the utility, as it focuses on operations and maintenance instead of new capital projects.

The new cuts come in addition to 150 jobs set for privatisation in the Corporation's engineering and construction services division.

“It's about getting the organisation right,” Water Corporation chief executive officer Sue Murphy has told the ABC.

“We did delay coming out to our staff with the detail until all of the employee support mechanisms were in place.

“We're doing this process as thoroughly as we can to make sure that we're not releasing roles until we're sure that we don't need them and making sure that ... we're not affecting maintenance levels or customer service levels.

“We've communicated with our staff when we know what we're saying and not before.

“When people are worried by rumour all we can do is tell them what we know to be true.”

Water Corporation says the first employees on the chopping block will be informed in coming days.

“We are doing ongoing detailed analysis of every role in the business,” Ms Murphy said.

“As we find roles that we don't need so much, we'll be removing those.”

WA’s Opposition water spokesperson Dave Kelly said the Water Corporation was now heading in the opposite direction to its strategic development plan, which came out just nine months ago.

“That five-year plan said the Water Corporation needed to spend an extra $950 million on capital in order to maintain its asset base and to prevent serious deterioration of the water supply system,” he said.

“Almost as soon as the five-year plan came out where [the Corporation] asked for more resources, there's been rumour after rumour of cuts and job cuts, and trimming of capital expenditure.

“There's just been a constant stream of information coming out, leaking out that the Government was intent on cutting the Water Corporation's budget.

“What it looks like to me is these cuts are short-term budget cuts to fix the Barnett's government overall budgetary position, rather than a well thought out strategy in the best interest of the Water Corporation and its customers,” he said.