<P> If it were not for the Nile River, Egyptian civilization could not have developed, as it is the only significant source of water in this desert region . </P> <P> Its other importance was its function as their gateway to the unknown world . The Nile flows from south to north, to its delta on the Mediterranean Sea . The floods were seen as the annual coming of the god . Possibly Egyptian mythology was based on this understanding, creating stories of gods or nature to give added importance to the processes and cycles that sustained Egypt . </P> <P> Whilst the earliest Egyptians simply laboured those areas which were inundated by the floods, some 7000 years ago, they started to develop the basin irrigation method . Agricultural land was divided into large fields surrounded by dams and dykes and equipped with intake and exit canals . The basins were flooded and then closed for about 45 days to saturate the soil with moisture and allow the silt to deposit . Then the water was discharged to lower fields or back into the Nile . Immediately thereafter, sowing started, and harvesting followed some three or four months later . In the dry season thereafter, farming was not possible . Thus, all crops had to fit into this tight scheme of irrigation and timing . </P> <P> In case of a small flood, the upper basins could not be filled with water which would mean famine . If a flood was too large, it would damage villages, dykes and canals . </P>

When the nile river flooded what did it leave behind