Kapiti Coast District Council has identified 40 sacred Maori sites on which owners will not be allowed to subdivide, alter existing buildings, or disturb the land.
Letters were sent to affected property owners last month, giving them four weeks' notice that the historic status of the waahi tapu sites would be included in the new district plan, to take effect this week.
Owners have been told submissions on the proposal close on March 1.
The latest proposed change to the district plan follows the announcement in August that the values of 1800 beachfront properties would be affected by new predictions of 50 and 100-year coastal erosion zones.
The council commissioned three local iwi, Te Atiawa ki Whakarongotai, Ngati Toa and Ngati Raukawa, to look at possible sites of historic interest to them on the Kapiti Coast.
About 400 were identified, which have been trimmed to 40 for inclusion in the proposed district plan.
Waikanae Community Board chairman and lawyer Michael Scott said yesterday: "Yet again the council has potentially undermined people's property values.
"They should have discussed the issue with property owners before dropping the information on LIMs [land information memorandums] and titles.
"In the worst-case scenario, a farmer will be allowed to graze stock but not be allowed to disturb the land surface, and a section owner only allowed to use certain types of foundations.
"More than that, you will not be able to dig a hole and put a swimming pool in. Some of these notices are going to drastically affect people's property."
He believed the council was leaving itself dangerously exposed to compensation claims, following any judicial reviews of its decisions.
One property owner, who did not want to be named, received a council letter last month "out of the blue" stating that Maori researchers believed a pa site and an urupa may have been on his land.
The letters outlined restrictions on what could be done on the land, including earthworks, modification of existing buildings and subdivision. The only land disturbance permitted was "for the purpose of human burials".
The property owner said the property had been in European ownership and farmed since 1830. Previous owners had never mentioned a pa site, and the land had been extensively modified over the years. He planned to appeal against the council's move.
He feared it would allow Maori to walk on to his land and start burying their dead, but council sustainable development manager Jim Ebenhoh said the proposal would not give people the right to go on to private land not at present used for burials and inter people.
"Urupa which are active cemeteries can continue to be used for that purpose, allowing for the possibility that, if a group gained ownership of land where an urupa had been situated, they could reactivate it," Mr Ebenhoh said.
Jonathan Smith, who plans to build an eco-village on his Waikanae North land, also received a letter about a waahi tapu site on his property.
"I am concerned about how the process has been managed, the late timing. Present-day landowners could have been more involved in the process."
He had already recognised a waahi tapu site on his land by creating an open space. "Now they say there was a pa site and an urupa. Where does an urupa start and stop?
"I do not think there has been much thought about the consequences for present-day landowners. I would like to recognise the value of it without being clobbered by it."
- The Dominion Post