Council has called for an environmental impact statement on the entire plan to upgrade the highway between Katoomba and Blackheath rather than the "inadequate" version prepared for the short Medlow Bath section.
In its submission to Transport for NSW about the Medlow Bath proposal, which would see a four- to five-lane highway extending from the wall of the Hydro to the railway tracks, council said TfNSW was treating Medlow Bath and its community of 600 as "a problem to be overcome".
It criticised the review of environmental factors (REF) prepared for that section and said the enormous impact of the proposal demanded an EIS.
"TfNSW's attempt to assess the environmental impact of only a 1.2 kilometre section of the GWH upgrade through an REF, in isolation from the remainder of the proposal, inevitably leads TfNSW into error and allows an inadequate assessment to be presented.
"An EIS is warranted given the potentially significant environmental impacts arising."
Council further said that TfNSW was bound by the Environment and Planning Assessment Act to conduct an EIS.
"Guidance from the NSW Land and Environment Court makes it clear that the practice of 'salami slicing' larger projects into smaller segments to avoid having a significant environmental impact and thus avoiding the obligation to prepare an EIS, is unacceptable."
While recognising that the highway is a national important corridor, council pointed out it also links Mountains villages so its impact should be assessed in the context of both its national and vital local roles.
"The regional level benefits of the upgrade appear to carry disproportionate weight in the assessment, at the expense of the local."
It said the corridor between the Hydro wall and the train line was never intended to accommodate five lanes of traffic (two each way plus a turning lane) and would have adverse impacts.
These include the quality of the village, the removal of heritage plantings, pedestrian refuges to be replaced with a visually intrusive pedestrian bridge and removal of on-street parking in the village.
It also said the REF didn't give proper weight to issues of noise impacts and loss of amenity to Medlow Bath residents and businesses.
"Medlow Bath's quality and function as a village will be reduced to a place to 'move through' rather than 'move within'."
Council said TfNSW's plans in effect created "a 'bypass' but through the centre of the historic village".
Because of this, TfNSW should consider alternatives. "The lack of engagement and co-design ... with community stands in contrast to the approach adopted elsewhere in the corridor."
TfNSW held extensive consultations in Blackheath, including having a dozen residents on a co-design committee.
Council said a tunnel was the "principal alternative option".
"A weighted assessment of this option would consider the traffic function and design speed, the amenity and heritage impacts/benefits, environmental impacts/benefits, alternative use of the Medlow Bath section of the highway for local and tourist traffic, public domain improvements, planting, on-street parking and as an alternative link road, set against the drivers of time and cost."
The REF failed to consider the long-term effects on ecosystems which support endangered species including the Blue Mountains water skink and giant dragonfly, as well as Blue Mountains swamps.
It also did not adequately consider the adverse impacts on the Hydro Majestic, which is set well back from the highway and allows a "respectful viewing space" through which people can view the dramatic drop into the Megalong. A five-lane highway up to the hotel's wall would remove that.
And it provided no data to support the future need for the pedestrian bridge, which would have a "significant visual impact" on the village. Council's submission said the "relatively minor improvements to accessibility and safety" of a bridge didn't offset the substantial adverse effects.
The submission has already been sent to TfNSW to meet deadline but is expected to be endorsed at this week's council meeting.
