LEITH FLOOD PROTECTION.

Otago Daily Times, Issue 21266, 21 February 1931, Page 12

LEITH FLOOD PROTECTION.

If the scheme which is recommended by Messrs MacLcan, Wilkie and Alexander in their report, published by us this morning, for the, protection of properties liable to be affected in times of serious floods in the Leith were one that could not be dealt with piecemeal, it would clearly have to be regarded as impracticable in existing circumstances. The total cost of the works which, in the opinion of the engineers, should be undertaken to afford reasonable immunity is estimated by them at £617,538. It would be idle to assume that authority could be secured by any local governing body to raise a loan at the present time of the magnitude necessary for giving effect to all the recommendations that have been made by the engineers. Fortunately their scheme is of a nature that lends itself to an exceptional extent to dissection, so that, it would seem, one recommendation may receive

attention at a time without prejudice to the scheme as a whole. For instance, the report expresses the opinion of the engineers that substantial alterations should be made in the structure of the bridges that have been constructed across both the Leith and Lindsay’s Creek. In some instances bridges should be renewed; in others, they should be heightened. so that increased waterway may be provided; in others, again, they should be wholly reconstructed. It is impossible to avoid the conclusion that in certain respects the report involves a reflection upon engineering methods in the past. Thus, while the Union street bridge, a costly structure, was erected within recent years after an experience of a flood that partially demolished the then existing bridge, it is now stated that it provides insufficient waterway. This same criticism is applied to a number of bridges which were apparently constructed at a level that did not allow adequately for the contingency of floods, though this should hardly have been disregarded. The importance of removing obstacles, such as insufficiently high bridges offer, to 'the free flow of flood water will be generally appreciated.' The recommendations which the engineers have made that the Leith should be widened at a few points and that deviations should be made are clearly directed also to the object of reducing the risk that flood waters may overflow the banks. It will be observed that the channel of the Leith below Union street is regarded by the engineers as too narrow and that a width of 100 feet from Leith street to the outlet is favoured by them. An additional precaution of obvious value against flooding is recommended in the construction of boulder traps. Most of the recommendations, therefore, may be adopted from time to time quite independently of the other recommendations. This is a distinct merit in the report at a time when all local authorities are likely not only to be straitened in their everyday finance but also to have their opportunities of raising money restricted through the occurrence of a more or less general financial stringency. '