Proposed diversion canal scheme, 1896

Proposed flood diversion canal scheme, 1896. Under J.B. Henderson’s direction, the Water Supply Department investigated a variety of flood mitigation schemes to protect Brisbane from future floods. A report was presented to Parliament in 1896 and included this map of two flood diversion canals. According to Henderson, at the time there appeared to be a ‘prevailing belief  ̶  that without difficulty a canal could be formed at some point on the river to the sea by means of which floods below the canal entrance at the river end would be wholly averted.’ However, building them would not be simple. Either canal would involve the purchase of much land, the construction of several new bridges, revetting to protect embankments, and finally an inlet weir. According to Henderson’s calculations, the excavation alone would cost £9,523,194 for the upper Oxley canal, shown in orange, and about £7,138,000 for the lower Yeronga canal shown in light blue. In addition to affecting navigability and tidal behaviour of the Brisbane River, the canals would need frequent dredging. Henderson advised parliament to abandon consideration of this and other similar schemes. Queensland votes and proceedings, vol.4, 1896