=Wadi Kalalat= heads in the north-west portion of Gebel Kalalat, and courses nearly eastward to reach the sea in latitude 23° 52′. For the first two-thirds of its course of about thirty kilometres, Wadi Kalalat is shut in by high hills, and falls rather rapidly. At its head a rough steep pass is said to exist into the head of Wadi Shut. After passing round the north flank of Gebel Kalalat, the wadi receives two small tributaries called =Wadi Um Maiat= and =Wadi el Dibag lil Batoga=, the former draining the north-east face of Gebel Kalalat and the latter the north-west face of Gebel Batoga. After receiving Wadi Dibag, the Wadi Kalalat makes a bend northward for about two kilometres, then turns south-eastward to the opening of the hills on the coast-plain. About two kilometres above the point where it leaves the hills, on the south side of the main wadi, is a rocky gully containing the =Galt Batoga= a rock basin which contained good water in 1907 and which is very easy of access in a few minutes from the main wadi. About one and a half kilometres further down, the small =Wadi Um Sellim=, draining the north-east parts of Gebel Batoga, joins the Wadi Kalalat just before it opens on to the coast-plain. The course of Wadi Kalalat from here to the sea, about eleven kilometres, is ill-marked, over a sandy plain. A ruined enclosure of considerable size, called =Garia Kalalat=, lies close south of the wadi about seven kilometres from the sea. =Wadi Um Goran= is a small wadi draining by many heads from the east face of Gebel Batoga and its foot hills to the sea in latitude 23° 50′. =Wadi Kunserob=, draining the south parts of Gebels Kalalat and Batoga, courses at first nearly southwards, then curves round south of Gebel Dibag, and after receiving =Wadi Dibag lil Kunserob= from the north-west, proceeds eastward through the hills and across six kilometres of sandy coast-plain to the sea in latitude 23° 47′. =Wadi Abu Berigâ= is a short drainage line from among the hills to the sea, a little south of Wadi Kunserob. =Wadi Khoda= is an important main drainage channel some forty-five kilometres in length, coursing a little north of eastward to reach the sea in latitude 23° 43′. For the greater part of its length it is shut in by high hills, only the last six kilometres being across the sandy coast-plain. With a basin approximately 780 square kilometres in area, it drains the mountains of Abu Dahr, Dahanib, Shut, Reyan, Shenshef, Hindia, and Um Akra, some of which rise to over 1,000 metres above the sea; it thus receives a fair amount of water in rainy years, and is well supplied with trees and bushes. Its average fall is about nine metres per kilometre.