(a) Mastering the Floods
The inundation let loose at the most critical period of the battle of the Yser, when the enemy had succeeded in crossing the river at Saint Georges, Schoorbakke, Tervaete and near Oud-Stuyvekenskerke, could not at first be so regulated as to harass the enemy only. It had gradually invaded part of our own trenches, and it was therefore an urgent matter to get the waters under complete control, lest the heroic means employed should compel the Belgian Army to abandon positions held hitherto at so serious a cost of life. To effect this, important works had to be put in hand without delay; some for defence, others for offence.
The first defensive measure consisted in the construction of trenches, which it was imperative to build at once, whether in water which oozed up at all points or in deep mud. Working with feverish activity, men piled sand-bags, brought up in a constant stream from the rear, on the marshy soil. In this manner parapets of a steadily increasing solidity slowly formed a continuous front which, though still of doubtful strength, sufficed to protect the occupied zone against surprise attacks.
Before the business of putting the ground in a proper state of defence could be initiated, the inundation had to be got under effectual control. This implied, let us note, the power to flood the ground on the enemy's side at will, while preventing the water passing beyond a sharply defined line, and making it quite impossible for the enemy to threaten us in turn.
The enormous technical difficulties which our engineers had to overcome can easily be imagined. We may observe, in the first place, that the Yser district is intersected by many small tributaries of the river and by a number of interconnected canals. The two zones—our own and that of the enemy—thus had direct communication with one another, so that, unless minute precautions were taken, and a great deal of work done, it was not possible to flood either zone without exposing the other to a similar fate.
AN ARTILLERY UNIT'S CONTROL POST
BATTALION HEADQUARTERS IN THE FRONT LINE
