Wednesday, 13 December 2017
Bridge Meeting Report
On Tuesday the 12 Dec a forum was convened by Moreland council, Pitt & Sherry engineers re discussion of the washed out Ronald St footbridge over Edgars Creek. The aim of the meeting was to give stakeholders an opportunity to express their views on a replacement structure and its potential alignment and allow council and contracted bridge engineers to report where they were at in terms of finding an adequate solution to the problem.
The sticking point to a resolution comes from Melbourne Water who will not allow the construction of a replacement structure that does not span the distance of a ten-year flood level mark. Using this as their brief the engineers highlighted three possible scenarios in which a solution may be achieved.
Option 1 - Reconstruct a bridge on the original alignment, the pros being that concrete paths are already in place from the previous structure, with the cons being to span the 10-year flood level the bridge may end up being up to 100 metres in length.
Option 2 - Involves constructing a bridge in the same area closer to the dog swimming area which is higher ground and easily spans the ten-year flood level, the pros to this seem to be a bridge span of half the size of option 1 and the cons are loss of vegetation, construction of new paths to link with the existing and a bridge that would seem to require a great deal of engineering as to safe grades as there is a considerable change in levels from one side of the creek to the other.
Option 3 - Upgrade the gravel track on the northern side of Edgars creek up to the Kodak bridge, with the pros being council not having to reconstruct the bridge and the cons being the creation of all-weather paths over a considerable distance that are shared paths, ie also used by maintenance vehicles such as tractors and trucks, the steepness of the grade to get people up to the height of the Kodak bridge access point was cited as a concern as was safety for walkers as the area is isolated and less used. Vegetation would also need to be removed in order for construction of paths, and drainage considered as this side of the hill is prone to much seepage to the surface after rains creating slippery pathways. From my observation, this was the least favoured of the 3 options.
In summing up from my understanding, Council had seemed to not have used or disregarded existing plant studies in the area, engaging other vegetation specialists that seemed at odds with members of the Edgars Creek planting group. There was also no data cited from a monitoring study of the frequency of the old bridge which was documented when the Coburg Hill estate was seeking planning approval. There has also been no modelling as to what the impact may be from the removal and sculpting of the concrete drain area that abuts the old bridge to determine if this may positively decrease the relative size of the ten-year flood area, which may result in a smaller bridge in the original alignment.
All areas that may require excavation must also be in accordance with the preservation of Aboriginal sites if they are to be found in an option area.
The bridge engineers have put a ballpark figure of 1 million dollars to construct a new bridge that will satisfy Melbourne Waters requirements. Council have put $50,000 dollars towards a feasibility study and have not committed to beginning construction for up to 2 years.
Comments can be directed to council or Pitt & Sherry bridge engineers.