Six farmers with more than 10,000ha in the Jurien region will be affected if a priority one zoning restriction is put in place under the policy.

A zoning restricts the practice of various land uses that are viewed as a threat to the quality of drinking water.

Shadow agriculture spokesman and Moore MLA, Gary Snook, said decent, hard-working farmers and their families would be sent to the financial and human scrapheaps if plans to introduce a zoning restriction went ahead.

"The Department of Water is proposing to place a Priority One Zoning Restriction over 10,000ha of land north-east of Jurien Bay which will effectively put six farmers out of business," Mr Snook said.

He said under the restrictions of the department's protection notice, farmers could no longer crop their land, have stockyards, store fuel or chemicals, have kennels for their dogs, or run their business from their home.

Mr Snook said all of these uses and dozens more were not permitted under the proposal P1 Zoning which, if gazetted, would put farmers out of business.

"Apart from being an outrageous attack on farmer's rights to farm their land and feed their families, it will permanently devalue their land," Mr Snook said.

"It is totally immoral for any government to take away a farmer's right to use and enjoy the capital value of their farm and is a clear case of eroding a farmer's property rights.

"His life savings and superannuation are tied to these rights."

Mr Snook said affected landholders had no avenue of appeal if they oppose the selected proposal.

The department's water resource management director, John Ruprecht, said whatever the decision in terms of zoning restrictions, farmers could still continue to carry out existing land uses.

"We haven't done a detailed survey of existing land use at this point in time, existing land use can continue," Mr Ruprecht said.

"We will be encouraging best practice with practices such as cropping to minimise any impact on water quality.

"If at some point in time those land uses changed we would need to approve that change."