From the onset of the rains in early December, the Ruaha River had irregular bursts of flood waters, emanating from the various sand rivers in the Park and also in Usangu. This water flowed for several days at a time, all from local rainstorms, in different sections along its course but it was never a constant flow. The picture below shows the flood water from a rainstorm on the 27th December 2011. This flow lasted a few days only before drying up again. One can tell it is from local flooding due to its brown colour.
I suspect that the massive off takes in the Usangu area are greater than ever before. It is no wonder that Mtera Dam is not filling up very fast.
If the water was allow to flow naturally I feel sure that the river and hence the dam would be an awful lot higher than what we are witnessing at present.