Environmental group says expansion puts lake at risk

Lake Hayes has become the sink for sediment and nutrients from the lake's catchment, a concerned group says.

Environmental campaigners have warned of an increase in contamination levels in Lake Hayes if new developments are allowed to go ahead in the area.

The Friends of Lake Hayes Society (FOLH) made a submission last week, which focused on poor water quality in the lake, to a hearings panel considering Queenstown Lakes District Council's proposed district plan (PDP) for the Wakatipu Basin.

The society said high levels of nutrients and sediment entering the lake will only be made worse by further development in the catchment area surrounding it.

Society chairman Mike Hanff said the lake has ``effectively become the sink for most of the sediment and nutrients generated by the catchment.

``No monitoring or management measures have been put in place to assess the environmental performance of developments in the catchment during flood events.

``Clearly this system is not designed to protect Lake Hayes or Mill Creek from adverse contamination.''

The Wakatipu Basin land use planning study completed in March 2017 led to the proposed rural amenity zone (RAZ) and lifestyle precinct being included in stage 2 of the PDP, which aims to limit development and protect rural land in the district.

In its submission to the panel, FOLH opposed the PDP on the grounds that the land use planning study should be revisited to include impacts on the lake and the contribution of groundwater.

The group also called for the plan to restrict any further residential or commercial subdivision and developments in the catchment area until ``suitable reticulated sewerage is installed''.

It would like to see the district council adopt and implement a Lake Hayes catchment plan, with robust water quality protections and monitoring procedures.

In his evidence to the panel, Dr Marc Schallenberg said the level of phosphorus entering the lake needed to be reduced.

"Contaminants will increase with population growth and increased land use.

"Both Mill Creek and Lake Hayes already exceed water quality levels set by the central and regional government.''

The ORC has approved four new initiatives to improve water quality in the lake as part of its long-term plan, which will take place over the next year.

They include allocating $40,000 for a monitoring buoy to measure levels of algal bloom in the lake and $100,000 to pay for initial works to make improvements.

The funds will go towards building infrastructure to allow Arrow irrigation water to be diverted into Mill Creek to reduce the level of nutrients in the lake.

The council will also increase its water quality testing procedures in neighbouring Mill Stream and Hayes Creek, and intends to develop and consult on proposals to improve the lake's condition.

District council planners recommended that the society's submission be rejected.

joshua.walton@odt.co.nz