Posted by Scott Hackett on Wed, Jun 27, 2018 @ 7:17 AM
Australia’s island state, Hobart, is well known for its history of catastrophic fires, including the disastrous wildfires of 1897-98 and 1967. As the second-driest city in Australia, it’s easy to forget though that Hobart is also vulnerable to serious flooding. Until earlier this month that is, when a record 236.2mm of rain fell on Mount Wellington and 129.2mm fell in Hobart. The deluge flooded the city, with the Hobart Rivulet breaking its banks and flooding other lower lying areas in Sandy Bay, South Hobart, New Town, Lenah Valley and Kingston. In Hobart, cars were swept away in Collins St and Syme St and McRobies Rd in South Hobart.
Hobart’s closeness to nature and surrounding hilly terrain makes the city especially prone to wildfire and flash-flooding. But, the May 2018 flooding is also partly attributable to the city’s postwar planning. Like the rest of Australia, city planning in Hobart was dominated by, “a disconnection from nature. Creeks and streams were filled in, built over or walled off (taming nature), creating risks of catastrophic failure in unexpected conditions. This approach also overlooked the important ecological functions of watercourses.”
Unfortunately, the problem is only getting worst as Hobart expands, with houses, roads and buildings increasing the hardscaped area and decreasing green cover, which acts like a sponge. Planners now must apply water-sensitive urban design principles, including protecting floodplains from development, limiting the development of very steep land, and restricting land uses on flood-prone sites. Separately, thought must be given to the development of the urban forest – planting urban trees and carefully incorporating water sensitive urban design to better manage stormwater runoff. Good planning can help prevent future disasters and keep Hobart’s residents out of harm’s way.