‹‹‹ Vitr. 8.6.6 | Table of Contents | Vitr. 8.6.8 ›››
7It will moreover be expedient, when the level of the fall from the spring is obtained, to build reservoirs at distances of twenty thousand feet from each other, because if damage be done to any part, it will not then be necessary to take the whole work to pieces, and the defective places will be more easily found. These reservoirs, however, are not to be made on a descent, nor on the venter, nor on a rise, nor, generally speaking, in valleys, but only on plains.
7It is also not ineffectual to build reservoirs at intervals of 24,000 feet, so that if a break occurs anywhere, it will not completely ruin the whole work, and the place where it has occurred can easily be found; but such reservoirs should not be built at a descent, nor in the plane of a venter, nor at risings, nor anywhere in valleys, but only where there is an unbroken level.