(2) The Babylonians controlled the Euphrates, and at the same time provided against its time of “low supply”, by escapes into two depressions in the western desert to the NW. of Babylon, known to-day as the Habbaniyah and Abu Dis depressions, which lie S. of the modern town of Ramadi and N. of Kerbela.  That these depressions were actually used as reservoirs in antiquity is proved by the presence along their edges of thick beds of Euphrates shells.  In addition to canals and escapes, the Babylonian system included well- constructed dikes protected by brushwood.  By cutting an eight-mile channel through a low hill between the Habbaniyah and Abu Dis depressions and by building a short dam 50 ft. high across the latter’s narrow outlet, Sir William Willcocks estimates that a reservoir could be obtained holding eighteen milliards of tons of water.  See his work The Irrigations of Mesopotamia (E. and F. N. Spon, 1911), Geographical Journal, Vol.  XL, No. 2 (Aug., 1912), pp. 129 ff., and the articles in The Near East cited on p. 97, n. 1, and p. 98, n. 2.  Sir William Willcocks’s volume and subsequent papers form the best introduction to the study of Babylonian Deluge tradition on its material side.

(3) Their works carried out on the Tigris were effective for irrigation; but the Babylonians never succeeded in controlling its floods as they did those of the Euphrates.  A massive earthen dam, the remains of which are still known as “Nimrod’s Dam”, was thrown across the Tigris above the point where it entered its delta; this served to turn the river over hard conglomerate rock and kept it at a high level so that it could irrigate the country on both banks.  Above the dam were the heads of the later Nahrwan Canal, a great stream 400 ft. wide and 17 ft. deep, which supplied the country east of the river.  The Nar Sharri or “King’s Canal”, the Nahar Malkha of the Greeks and the Nahr el-Malik of the Arabs, protected the right bank of the Tigris by its own high artificial banks, which can still be traced for hundreds of miles; but it took its supply from the Euphrates at Sippar, where the ground is some 25 ft. higher than on the Tigris.  The Tigris usually flooded its left bank; it was the right bank which was protected, and a breach here meant disaster.  Cf.  Willcocks, op. cit., and The Near East, Sept. 29, 1916 (Vol.  XI, No. 282), p. 522.

It was only by constant and unremitting attention that disaster from flood could be averted; and the difficulties of the problem were and are increased by the fact that the flood-water of the Mesopotamian rivers contains five times as much sediment as the Nile.  In fact, one of the most pressing of the problems the Sumerian and early Babylonian engineers had to solve was the keeping of the canals free from silt.(1) What the floods, if left unchecked, may do in Mesopotamia, is well illustrated by the decay of the ancient canal-system, which has been the immediate