This study analysed the Morphometry of River Ahum in an attempt to investigate the likely causes of seasonal flooding as experienced in the past.  Extract from the Topographic map of Makurdi was used to define the river basin.  Stream channel discharge from the river was measured using the current meter during peak discharge in the month of September.  From the study a fern–shaped watershed was developed with a drainage density of 1.257, bifurcation ratio of 8.33 and 3.00 for the three order streams.  An area ratio of 0.149 and 3.2 was calculated while a stream length ratio of 0.937:8.615 was developed.  Findings also indicated that the stream length of order 1 outnumbered that of orders 2 and 3 which culminate in seasonal flooding at the rainfall peak of 69.2mm resulting from the low land overflow.  The discharge during the study was between 0.167m³/s – 4.719m³/s.  It is advisable to carry out more studies on this river for a period of years for purpose of forecasting flood events.