River morphology describes the shapes of the river channels and how they change over time. This study examine the morphology or channel adjustment along a 44.43-km stretch of the Lower Reach of Megech River in North Gonder of Amhara Region which drains towards Lake Tana and then to the Blue Nile, Ethiopia. The objectives of this study were to identify and examine the plan-form changes and to investigate the impacts and causes of the plan-form changes of the lower reach of Megech River for the last 30 years. Satellite images of the year 1984, 1995, 2000, 2006, 2009 and 2014 were used to extract the past and the recent channel plan for information. Typical channel cross sections at Megech Bridge were used for the comparison of vertical adjustment. Besides the above data, field observation and key informant interview were made. For data preparation and analysis, Image analysis software (ERDAS 2014), Arc GIS and Terrain analysis tools were used. Lower reach of Megech River has undergone major plan form changes past 30 years. At a distance about 19.3 km from the Lake, the river abounded the old channel course and shifted from west to east and developed new channel which directly drains to Lake Tana. The maximum shift was 4.64 km occurred in the left bank for the period 1995 to 2006 in reach 1, whereas the minimum shift of about 67.8 m was measured for the right bank for 1984 to 2000 and 20.9 m for the period from 2006 to 2009 in reach 7.The stretches showing the highest mobility are located to the left (east ward) in the downstream of the river reach (reach 1 to reach 4). The sinuosity of Megech River shows an overall increase of 8.2% for the 30 year study period. The general trend shows that Sinuosity of river Megech increases from 1984 to present. The Megech River registered an overall net gain of 74.2 % in channel area over 30 years. Generally, the plan form alteration of Megech River at different reach is due to natural and artificial influences. Therefore, responsible bodies should target to minimize the negative aspects of any interventions in the catchment and in the channel by designing appropriate watershed management and river restoration works.