Lake Eyre Basin Rivers 180 infrastructure. Plans are yet to be publicly released. Mount Isa still holds substantial mineral resources and could continue for decades. Potential environmental, health and social impacts could increase if the open cut developments proceed, without rigorous baseline assessments and environmental management. Risks to the flows and water quality of the Leichardt River provide significant lessons for the free-flowing rivers of the Lake Eyre Basin. 0 40 80 120 160 200 240 0 2 4 6 8 10 12 1930 1940 1950 1960 1970 1980 1990 2000 2010 0 130 260 390 520 650 780 1928 1938 1948 1958 1968 1978 1988 1998 2008 Lead (Pb) Zinc (Zn) Copper (Cu) (a) (b) Fig. 19.5. Long-term annual trends (1931–2014) in (a) lead (% Pb) in ore milled (green line) or mineral resources (open green triangles) zinc (% Zn) in ore milled (blue line) or mineral resources (open blue squares) silver (g/t Ag) in ore milled (dashed black line) or mineral resources (diagonal black crosses) and copper (% Cu) in ore milled (dotted red line) or mineral resources (open red circles) and (b) production of lead, zinc and copper from the Mount Isa mining complex (data updated from Mudd 2009). Or e grade silver (g/t Ag) Or e grades (%Pb, % Zn, % Cu) Annual production (kt/y ear )