Negative Impacts

Failure to address underlying causes of metropolitan water shortages - environmentally unsustainable growth coupled with wastage and inefficient use of water

Unwilling relocation of hundreds of businesses that form part of the social and economic fabric of the local community.

Unwilling relocation of hundreds of families.

Loss of approximately 76 square kilometres of high quality fertile irrigated farmland close to major population centres.  Relocating this activity will  cause huge environmental impacts somewhere else.

Requires disruption of all local major transport infrastructure - Bruce Highway, bridges, Mary Valley Road, Mary Valley Rail, telecommunications and power infrastructure.

Extremely shallow, variable water level will create an ideal environment for huge numbers of pest species - blue-green algae, water hyacinth, salvinia, cabomba, cane toads, mosquitoes, rodents, carp.

Decreased water flows to downstream communities and ecosystems- Gympie, Tiaro, Maryborough, Hervey Bay.

Uncertain effects on flood mitigation.

Ecosystem disruption in Great Sandy Straits 

Decrease in large existing tourism and fisheries industries in Great Sandy Straits.

Increased river bed and streambank erosion downstream.

Impacts on groundwater salinity.

Complete disruption of major remaining breeding habitat for 3 endangered and vulnerable vertebrate species -Lungfish, Mary River Cod and Mary River Turtle and destruction of  listed endangered regional ecosystems.

Tie-up of a huge amount of state investment that could be spent in other areas eg. education, health.

Sets a horrific precedent for state action in defiance of reasonable standards of community consultation and accountability.

Takes short-term pressure off developing more sustainable solutions for helping with metropolitan water consumption problem - eg. recycling, water tanks, efficiency, intelligent growth planning and restrictions.

Disruption of  cultural heritage sites, including aboriginal places of significance, heritage buildings and Kandanga cemetry.

Positive Impacts

Temporary relief in metropolitan water shortages sometime in the future - from the time construction is completed until demand  outstrips supply again.

Possible Increase in tourism-related industries in vicinity of dam wall

Climate moderation in vicinity of dam due to evaporation and heat storage.

Short-term employment and business opportunities associated with construction.

Increased biodiversity (mainly of introduced species)on that part of floodplain - eg water birds, marshland plant species.