Never trust an artist's impression of any proposed new development.
There are good reasons for this if only because however detailed and accurate the images may be, they may not be what gets built.
Even so, there may be room for a little optimism about what is proposed for the flood protection works between the St David St footbridge and the Union St bridge in front of the university's clocktower building.
There have been plans for this since at least 2006. Your columnist and others have commented on them, pointing to various shortcomings, in my case primarily aesthetic and to do with the loss of heritage. There have been submissions and court challenges.
At one time your columnist was one of a group who met and discussed things with the regional council's designers and engineers.
That was not exactly reassuring as it became clear the latter had difficulty grasping what we were banging on about. For them ''design'' was solely about function and their only aesthetic was modernist which they hadn't perceived is just one of several choices.
They hadn't noticed that in this stretch of the Leith, dominated by a Gothic revival building, the existing channel is a subtle piece of understated revivalism which the regional council's then chairman had unhelpfully characterised as a ''drain''.
The shortcomings of the earliest proposals included lowering the concrete walls on both sides and widening the channel, thus losing the sense of high and narrow confinement and the ghost of the original street line along Castle St.
Such details of the replacement concrete's treatment that were available showed Corbusier-esque ribbed fairfacing in place of the more granular finished original. The existing slab coping was not to be replicated.
The new design had more extensive lawns on the Castle St or western side, diminishing the present austerity of concrete, an effect its authors particularly liked.
Perhaps the worst feature of all was the extension of the St David St footbridge across the new overflow channel on the western side. The result was to make the footbridge one section of a trestle bridge like a railway spanning the Lena in Siberia.
Some of the biggest negatives remain but appear to have been somewhat mitigated. An image was published (ODT, 24.7.13) showing the new treatment of the footbridge.
The new widened channel now passes under the footbridge's western approach in the form of a broad concrete path raised somewhat above the present low water level.
That in turn is backed on the west side by a new low concrete wall behind which rises solid fill. The new bridge section is arched where it passes beneath the carriageway and the water side support is sufficiently thick to avoid the trestle impression.
This is a significant improvement and one hopes it happens. But wait, there's more good news. On the clocktower side the present wall is to be lowered though only a metre.
As this is acknowledged to be of little or no flood relief value it's a pity it's happening at all. Still, the picture shows its coping with a broad slab treatment rather like that there now. Again one hopes it actually happens. Who knows. Perhaps it will.
There's cause for concern here though because new wrought iron safety railing is to be installed along this wall.
I've never heard of anyone falling over there but if you change the present arrangements you will trigger new building code provisions. (Another reason to leave it alone.) The railing may or may not be of good design, I've seen no images, but anything at all will detract from the austerity of the present impressive arrangement.
There's a place where some cast, not wrought, iron railing would be good but both present and proposed arrangements make its provision impossible.
There are some images and plans on a report buried deep on the council's website which give some further indications. Downstream, in the middle of the block, on the Castle St side, the new flood channel widens and sadly becomes only partly a concrete path.
The rest is apparently to be lawn which would again diminish the present imposing austerity. More green is not always good and the present balance is about ideal. Turn these lawns into concrete. There are to be steps here to the higher level which one hopes will be.
At the road level all along the west side there is a new low wall, presumably for extra containment. It's proposed it should be faced with bluestone, at the university's expense, which here would be a folly. The present concrete has no bluestone and the new stuff needs none either.
What would be good would be a coarse aggregate finish on all of the new concrete, emulating the old. This is an improvement but could be better yet.
Peter Entwisle is a Dunedin curator, historian and writer.
