'Opening [of] Denison Canal', 1905 (ALMFA, SLT)

The Denison Canal at Dunalley is the only purpose-built sea canal in Australia. Agitation by east coast settlers to improve transport by avoiding the longer, often rough voyage around Tasman Peninsula led to Lt-Governor Denison commissioning a report in 1854. Tenders were called in 1901, and the canal was opened in 1905. The canal proper is 895 metres long, and 2.42 km with dredged approaches. Its width is about 34 metres at ground level and 7 metres at low tide water level. Water depth ranges from 2.6 to 3.9 metres according to tide. The original, hand-operated swing bridge was replaced by an electrically powered one in 1965. Formerly used by small vessels and east coast traders, the canal is now restricted to fishing and pleasure craft by shifting sand bars in Blackman Bay. Tidal scouring obviates the need for dredging of the canal itself.

Construction of the canal through Ralph's Bay Neck at Lauderdale resulted from deputations to Parliament in 1911, 1912 and 1913. After an aborted start on dredging in 1914, construction was further delayed by the First World War. Clamour from farmers and orchardists resulted in a contract being let in 1924 for a canal 3 metres deep and 10 metres wide at water level. Excavation proved difficult, storms filled the eastern end with sand, anticipated breakwaters in Frederick Henry Bay to prevent silting were too expensive, and the project was abandoned. The body of the canal has limited use for water activities, the dredged western approach is barely discernible and the eastern end is blocked by a substantial land barrier. The original swing bridge has been replaced with a concrete culvert.

Further reading: Roadside information panels at Dunalley; A Alexander, The eastern shore, Rosny Park, 2003.

Graham Clements