Please take the time to click on the above link to see just how close the Save Our Streets group are becoming to be an annoyance to the No Dam debate. It is worth reading because in the paper disruption in Unley is diminished and the disruption to Mitcham maximized. You wouldn't call it a balanced argument! There are currently 3 proposals that have been developed that allow for adequate flood protection and No Dam. All of the current options have culverts in Unley Streets. While the size of the culvert in Malcolm St varies in each option the size of the culverts in Arundel Ave get larger. Putting the culvert in the rail reserve is a proposed but unpriced option.
While the Worley Parson's report at.
http://www.unley.sa.gov.au/webdata/resources/files/WP%20report%20-%20Bypass%20Culvert%20Assessment%2026-4-12%20(no%20appendices).pdf says that there may be little tree damage; the evidence that we have all seen in Devon St suggests otherwise. The other bit left out is that the hole that needs to be dug to put in a culvert needs to be 2m wider than the culvert and over 1m deeper. So if the culvert in Arundel Ave is 3.3m wide the hole dug would need to be 5.3 m x 3m. The residents in Unley have already had trucks running through their streets for almost a year with the railworks, they have had enough and should not be subjected to unnecessary and expensive works if the Ellison's Gully dam is viable. At this time there is no option on the table that has a do dam and no culvert option.