Trees grow well in Tanuf wadi; there is some surface water throughout the year & occasionally very deep pools can form, not to mention the dirt road being washed away.
P.S as of a couple of days ago, I could not get anywhere near this area because the track has been totally flooded – so my return for more rock art will have to wait 😦
David A Lockwood 
So refreshing to see those lovely splashes of green.
Yes it is – there is always lots of water in Tanuf.
Give it a few months of cold and you will miss all the sun 🙂 have a safe trip back home.
David.