ID is tentative, needing some expert input.
Lepidosperma curtisiae was the best fit for this plant: leaves twice as long as culms; culms biconvex; leaves terete and about 1 mm diam.
The tussocks were growing in a shrubby semi-shaded moist area, and although culms were erect, the leaves were lax and flopped. Culms were somewhat hidden amongst the leaves (see second photo). Culm length to first spikelet ranged from 13 to 25 cm; leaf lengths were up to 1.2 m, leaves were terete. Shade may have affected growth.