Exodus 7:19

19. Stretch out thine hand upon the waters of Egypt The language of this verse shows a minute acquaintance with the extensive and complicated water system which was peculiar to Egypt. The streams are the arms which branch out from the Nile, just north of modern Cairo, through the great plain of the delta, carrying the waters down to the Mediterranean. There are two principal and five or more lesser streams. The rivers are the canals running each side of the Nile, and receiving their waters through sluices at the time of the inundation. As the land sloped northward, the water was conveyed through main canals running along the southern or higher side of each field, and thence it spread through branches, straight or curved, down northward over the land. The ponds were the large standing lakes left by the inundation; and the pools literally, every collection of their waters were the smaller ponds and reservoirs which they used who lived at a distance from the river.

Wood… stone This is also a peculiarly Egyptian touch, for the Nile water was kept in large stone tanks for public use, and was also filtered and purified for domestic use in smaller vessels.