Stormwater is also a resource and important as the world's human population demand exceeds the availability of readily available water. Techniques of storm water harvesting with point source water management and purification can potentially make urban environments self-sustaining in terms of water.
Rivers flow downhill to sea level (generally speaking; some end in other bodies of water or join another rver). They flow with gravity from a higher elevation to a lower. The Nile rises on the western flank of the Great Rift Valley (many people consider Lake Victoria to be the source) and the Blue Nile joins the White Nile at Khartoum. The land falls away towards the north, thus the river flows north until it reaches the Mediterranean Sea at the Nile Delta. Direction of flow of a river is determined by elevation of the drainage basin, not geographical (North, South etc.) direction. http://en.wikipedia.org/wiki/Nile#Course.
The Nile River is one of the oldest, longest, and most famous rivers in the world today. Itâs over 4000 miles in length. Most people actually associate the Nile River with Egypt, but only one fifth of the actual course of the river runs through that country.. One of the unique features about the Nile River is the fact that it flows north, which is opposite the direction most rivers go. This means the Nile River originates in South Africa and then flows towards the Mediterranean Sea.