GREEN campaigners say a decision to defer a plan to build homes near a delicate eco-system is a victory for rare wildlife.

A decision to build 10 affordable houses on grassland in Warren Crescent was deferred by councillors following criticism by Friends of Lye Valley and local allotment holders.

Lye Valley, to the east of the Churchill Hospital, contains 20 rare plants and a very rare bog.

It is also a Site of Special Scientific Interest (SSSI).

Now they are hoping a decision to defer judgment on the scheme may draw a line under future development there.

The group said the delicate balance of the eco-system would have been destroyed by the drainage system which applicants Turley Associates, acting on behalf of Oxford City Council, had proposed.

Fears that the Town Furze allotment patch would die off because muck-depositing vehicles would be blocked from entering were also cited as a reason for putting the plans on hold.

And members of East Area Planning Committee have agreed that there is insufficient information about the impact on the site to decide.

Chairwoman of Friends of Lye Valley Dr Judy Webb, who has been studying SSSIs for more than 10 years, welcomed the move and said it should spell the end for attempts to build homes on the site.

She said: “There is not enough information in the application to be sure that this mitigation will actually work forever to protect the fens. Therefore the housing should not happen, it is too risky.

“The fens have already been seriously damaged by surrounding urban development, enough is enough. It threatens the wildlife of the Lye Valley because the green area adjacent to Warren Crescent is in the catchment of the springs which feed the wetland SSSI and fens immediately adjacent.

“Building and paving over this area would prevent rainwater entering the soil and percolating down so that it can feed the springs.

“Potentially the springs may produce less water and the wetland become drier, with loss of species.”

Turley Associates had drawn up a mitigation plan to push water into the soil to overcome this problem.

But Dr Webb said it would only work in the long-term with proper monitoring, and had never been attempted before.

The Friends say they are also concerned that occupants of the houses will have to be stopped from paving over their green back gardens to make sure they stay permeable.

Friends member Jane Alexander added: “What they were proposing had never been attempted before and could have had a hugely damaging effect on wildlife.

“There is a calciferous bog in the SSSI, which is very rare, and the development would cut off all the extra nitrogen which feeds the soils.

“We have already lost an orchard due to development in recent years, and all the insects and everything else that comes along with it. There should be no more homes built here.”

Calciferous bogs are formed on top of a limestone formation. They are rare because limestone formations usually act like a sponge and water cannot stand very long on top of limestone without disappearing into the water table.

There are 20 types of plant on the Rare Plants Register in Lye Valley which exist in fewer than 10 other county sites.

Oxford City Council and Turley Associates did not offer comment when approached.

It is not known if the application will reappear.