Water hyacinth (Eichhornia crassipes) is one of the major challenges in Lake Tana, negatively impacting the surface area coverage of the lake, and the wetlands around it. This study aimed to investigate water hyacinth's (WH) morphometric characteristics and harvesting methods in Lake Tana, in the northwest highlands of Ethiopia. An explanatory research design, satellite images, field observation, field measurement, and literature reviews were used. Descriptive statistics were applied to analyze the quantitative characteristics of WH morphometric characteristics. Stata was applied to compute the statistical analysis of the data. The results showed that the spatial distribution of the weed was 10.59 km² (1059 ha) in the dry season of 2024 (January) and 7.372 km² (737.2 ha) in the wet season of 2023 (August). WH showed a mean leaf length of 9.47 cm, leaf width of 10.6 cm, stem length of 33.63 cm, stem diameter of 2.3 cm, root length of 121.8 cm, root diameter of 8.5 cm, root shoot ratio of 3.7, leaf blade area of 57.8 cm², and leaf area index of 55374.03 cm². In addition, a mean of 21 leaves per plant and 47 plants per 1 m² was found. The average fresh and dry weight of WH was 62.09 kg/m² and 4.63 kg/m², respectively. The total wet biomass of WH in Lake Tana was 457,727.48t/year in the wet season of 2023 and wet WH biomass of 651945t/year in the dry season of 2024. On the other hand, the dry biomass of WH was 34,132.36t/year in the wet season of 2023 and 48,615t/year in the dry season of 2024. Furthermore, the net value of machine harvesting was $6,236,833.82/year. Monitoring water hyacinth’s morphometric characteristics and identifying cost-effective harvesting methods is crucial for effective lake management. Machine-based harvesting was found to be a cost-effective and preferable method. Although machinery harvested more biomass, integrated method is essential for effective WH harvesting, Lake Tana conservation, and sustainable management.