of the way underground, before discharging into the Torrens at Felixstow. Fourth Creek, or Morialta Creek, arises on the other side of Norton Summit, with various tributaries flowing into it from Marble Hill and Lobethal. It is most well known for its falls in Morialta Conservation Park. "Moriatta", a Kaurna word meaning "ever flowing", is now the official name of Fourth Creek. This name has been adapted to Morialta, which is now the name of an electoral district, school and the park through which the creek flows. Fifth Creek arises within the Morialta Conservation Park, runs alongside Montacute Road for some way and discharges into the Torrens at Athelstone. The largest catchment of the Torrens is Sixth Creek in the Adelaide Hills, which joins the Torrens at Castambul on Gorge Road. Water flow At the time of European settlement the river was a summertime chain of waterholes bounded by large gum trees. Flowing through the area where the city of Adelaide is sited the river was sometimes invisible beneath its gravel stream bed. It frequently flooded in winter and did not reach the sea, instead ending at coastal dunes where its waters created a vast but shallow freshwater wetlands. These wetlands, known as The Reedbeds after the dominant vegetation, occupied a large area of the western Adelaide Plains and were also fed by other waterways. The river only flowed to the sea through the Port River, Barker Inlet, and Patawalonga River following heavy rain. The river's catchment area of approximately is the largest of any waterway within the Adelaide region. The upper reaches are used to create a potable water supply for metropolitan Adelaide with the river supplying three of Adelaide's eight reservoirs. The upper catchment has an average annual rainfall of between at its eastern end to near Uraidla. The Torrens has a very variable flow leaving early settlers to use trial and error in determining bridge heights, with many bridges consequently being washed away. Due to the variability of Adelaide's climate, flow rates can change from a trickle to flood conditions quickly. On 5 June 1889, prior to major flooding, the flow rate before it entered the suburbs was , rising to , eight days later. Since settlement it has repeatedly flooded, sometimes with disastrous consequences. Adelaide's western suburbs were especially prone to flooding due to their location on the river's alluvial fan. As development of Adelaide progressed