Search for new snail habitat
THE Nathan Dam project has been delayed for at least another two years, while scientists search for a suitable new home for the endangered boggomoss snail.
A small population of about 100 snails live in the boggomoss habitat at Mount Rose Station which would be flooded if the Nathan Dam proceeded.
SunWater has been undertaking a detailed engineering, financial and environmental study for the Nathan Dam and Pipelines Project since July 2007.
As part of the Environmental Impact Statement (EIS) process they commissioned a series of surveys across the dam and pipeline areas for plant and animal life, including possible relocation for the Mt Rose snail population.
Nathan Dam project manager Peter McTaggart said the surveys were complete and produced some interesting findings particularly in relation to the boggomoss snail.
A trial was staged to see whether the snails would survive being relocated to an alternative habitat.
The trial, conducted by Dr John Stanisic, found that the population size was sufficiently robust to withstand the movement of some individuals.
Mr McTaggart said the translocation trial involved moving individual snails from the Mt Rose population to two sites considered to be suitable habitat and not directly affected by the proposed Nathan Dam inundation area.
“The purpose of these trials is to determine whether the snail can be moved successfully and if so, this would be proposed as a means to mitigate the impacts of the dam,” Mr McTaggart said.
Mr McTaggart said the trial would take a minimum of three years, as it needed to demonstrate the snails could breed and produce viable young for two generations.
“This extended timeframe for the trial has meant that the current EIS studies are not on hold until such time that the translocation trial appears to be successful.”
He said the trial would extend the business case by a minimum of two years.
“SunWater remains of the view that the Nathan Dam and Pipelines Project is the best long-term water supply solution for the Dawson-Callide sub-region.
“SunWater will focus its efforts in the short term on successfully completing the (snail relocation) trial, with the intention of resuming the remaining technical studies when the trial is underway and initial results have been obtained.
“We anticipate that they will complete the feasibility study, EIS and Business Case in mid 2012 and dam construction by 2015.”
Dr Stanisic's survey also revealed that the Mt Rose snail population was bigger than original estimates.
It was thought the population was made up of about 100 snails, but this has been revised to greater than 350.
A larger population of about 1000 adult snails resides in a small separate habitat in the Isla-Delusion area.
This population is constantly under threat by fire and trampling by stock.Snail trail
- The boggomoss snail occurs in two populations in the Dawson Valley, northeast of Taroom, on the Dawson River.
- The larger population, estimated at 1000 mature adults is in a small patch of riparian habitat as Isla-Delusion.
- The smaller population, directly under threat by the dam, is in a boggomoss habitat at Mount Rose Station, on the Dawson River.
- Boggomosses are a series of small, elevated peat bogs or swamps scattered among dry woodland communities.
- There is a 50% probability the population will become extinct in the wild in the next 20 years.