The problem word of this verse is undoubtedly . In Old Testament parlance, this term has generally been translated as 'firmament'; but there is merit in considering Holladay's relevant comments:
: (beaten, [metal]) plate, firmament' (i.e. vault of heaven, understood as a solid dome) GN 1:6.
The basic meaning of the word was something firm, or solid, that was capable of dividing 'waters' into two parts; and in the context of Kharsag and its Reservoir of water, the term fits neatly as an expression for the 'dam wall'. This was a kind of 'plate'; and standing at its base and looking up to its heights, it would have seemed to reach up to the heavens.
The intention of the verse emphasises that before the dam was built there was only one source of water - the river; but, afterwards, there were two accumulations - the one in the reservoir and the other in the watercourse and irrigation channels below.
|jerusalem bible||(alternative genesis)|
|God said: 'Let there be a vault in the waters to divide the waters in two'. And it was so.||The Shining Ones said, 'Let there be [built] a wall in the middle of the [river] waters, and let it separate the [upper] waters from the lower waters.' And it was done.|
The damming of the river at the mouth of the local ravine was a major work essential to the success of the Kharsag project, and no local 'creation story' would have been likely to overlook it. In this context, the building of the dam wall, which is recorded in Sumerian literature and indirectly referred to in Enochian sources is a far more believable operation than the placing of a solid vault in the sky to divide the waters of the heavens from the waters of the earth!