It's not only the Hymn to the Nile that says water spouted up but almost every ancient source. Most importantly is the Pyramid Texts themselves;
1551a. To say: This thy cavern there is the broad-hall of Osiris N..
...
1553b. They tremble who see the inundation (when) it tosses;
The water comes from a cavern and tosses.
Horapollo said;
"Egyptian language NOUN, and which, when interpreted, signifies New, they sometimes pourtray a LION, and sometimes THREE LARGE WATERPOTS, and at other times HEAVEN AND EARTH GUSHING FORTH WITH WATER. "
"And they depict three waterpots, and neither more nor less, because according to them there is a triple cause of the inundation. And they depict one for the Egyptian soil, as being of itself productive of water; and another for the ocean, for at the period of the inundation,"
Hieroglyphics of Horapollo: Book I: XXI. How the Rising of the Nile
The concept that this cool water was "osiris" (osiris N) permeates the PT.
507a. To say: N. is come forth to-day at the head of the inundation of the flood.
...
507c. effervescent, proceeding from leg and tail of the Great (One) who is in splendour.
508a. N. is come to his watercourses, which are in the land of the flood, in
Mḥ.t-wr.t,
508b. to the places of satisfaction, with green fields, which are in the horizon,
509a. that N. may make green the herbs in both lands of the horizon,
509b. (and) that N. may bring the green to the great eye which is in the midst of the field.
692c. He is effervescent; he is effervescent; Shu, let thy arms be about N.
868b. thy water, thy cool water-libation is the inundation of the Great One (who) which is come forth from thee.
They even name him "fresh water"!!!!
25a. Osiris N., take to thyself thy natron, that thou mayest be divine.
25b. Nut has made thee to be as a god to thine enemy (or, in spite of thee) in thy name of "god."
25c.
Ḥrnp.wi recognizes thee, for thou art made young in thy name of "Fresh water."
They also describe an "efflux" that falls from him and powers his ascent to the sky;
2109. The sky trembles, the earth quakes before the god, before N.
2110a. N. [is not enveloped] by the earth;
2110b.
’Iḫ.t-wt.t, thou art not enveloped by the earth.
The water is "N" and is driven by his efflux "
’Iḫ.t-wt.t"
2110c. Thy fame is by day; thy fear is by night, as a god, lord of f ear.
2110d. Thou commandest the gods like the mighty one, chief of the mighty.
This efflux which they also associated with foam on beer and bubbles in bread (CO2) drives the gods and collects in low lying areas at night when the wind dies. This creates pockets where all animal life will die.
2111. [O] Osiris, the overflow comes, the inundation hastens, Geb groans.
The inundation tosses!
There was a single Ancient Language that was metaphysical in nature and based on the logic of the wiring of the human brain. It is a natural language that is still used by all other life on earth but in much simpler forms and tailored to the needs of specific species. This writing from the PT is a confused translation of Ancient Language.