With Australian PM & Liberal MP Scott Morrison and the tail wagging the NSW Government dog, Deputy Premier & Nationals MLA John Barilaro, both backing the proposed Mole River dam it appears that yet another poorly conceived and badly placed dam will be built

 

Dam valley: The Mole River looking upstream from Ringtree and Braeside' to Alister, where more than 800 ha of productive land and native vegetation is proposed to be flooded by the dam.
Photo: Bruce Norris in Tenterfield Star

On 12 August 2020 the NSW Legislative Council Portfolio Committee No. 7 – Planning And Environment self-referred the Inquiry into the rationale for, and impacts of, new dams and other water infrastructure in NSW.

This inquiry looked into the rationale for, and impacts of, new dam and mass water storage projects proposed by Water NSW including Wyangala, Mole River and Dungowan Dam projects, the Macquarie River reregulating storage project, the Menindee Lakes Water Savings Project and the Western Weirs project.

Water NSW undertook a feasibility study of the Mole River in 2017 which stated that none of the dam proposals for this river were financially viable at the time.

In 2019 the Morrison Government gave its support for a 100,000 megalitre Mole River dam which it saw as not just supplying Tenterfireld Shire with water but also sending water to south-east Queensland.

This begs the question of where the bulk of the water would be coming from given the Mole River catchment annual rainfall was less than 600mm in 13 of the last 18 years (2019) and, as Professor Quentin Grafton, water economist, ANU and UNESCO Chair in Water Economics and Transboundary Water Governance tells us, at 600mm or less annual precipitation a dam will not fill.

Tenterfield Shire Council has long made it clear that it sees a potential relationship between a Mole River dam and water from the Clarence River catchment - viewing interbasin water transfer from Upper Clarence River tributaries (in particular the Maryland River) to the proposed dam site as desirable additional water storage which would allow for water diversion into the border rivers system for the benefit of Murray Darling Basin irrigators and/or the establishment of a hydro electric scheme with the shire.

Northern Rivers readers might also recall that the Mole River has a long history of arsenic contamination.

ResearchGate, December 2001:

Mining and processing of arsenopyrite ore at the Mole River mine in the 1920–1930s resulted in abandoned mine workings, waste dumps and an arsenic oxide treatment plant. Weathering of waste material (2.6–26.6 wt% As) leads to the formation of water soluble, As-bearing mineral salts (pharmacolite, arsenolite, krautite) and sulfates which affect surface waters after rainfall events. Highly contaminated soils, covering about 12 ha at the mine, have extreme As (mean 0.93 wt%) and elevated Fe, Ag, Cu, Pb, Sb and Zn values compared with background soils (mean 8 ppm As). Regionally contaminated soils have a mean As content of 55 ppm and the contaminated area is estimated to be 60 km2. The soils have acquired their metal enrichments by hydromorphic dispersion from the dissolution of As-rich particulates, erosion of As-rich particulates from the dumps, and atmospheric fall-out from processing plant emissions. Stream sediments within a radius of 2 km of the mine display metal enrichments (62 ppm to 27.5 wt% As) compared with the mean background of 23 ppm As. This enrichment has been caused by erosion and collapse of waste-dump material into local creeks, seepages and ephemeral surface runoff, and erosion and transportation of contaminated soil into the local drainage system. Water samples from a mine shaft and waste-dump seepages have the lowest pH (4.1) and highest As values (up to 13.9 mg/L), and contain algal blooms of Klebsormidium sp. The variable flow regime of the Mole River causes dilution of As-rich drainage waters to background values (mean 0.0086 mg/L As) within 2.5 km downstream. Bioaccumulation of As and phytotoxicity to lower plants has been observed in the mine area….

By the time the current Mole River Dam scoping report had been completed the Mole River Dam project had been declared Critical State Significant Infrastructure (CSSI) under Division 5.2 of the NSW Environmental Planning and Assessment Act 1979 (EP&A Act).

As a CSSI the project may be carried out without obtaining development consent under Part 4 of the EP&A Act.