The proliferation of water hyacinth is currently controlled by removing it from a water body and
disposing it by landfill in China. Using water hyacinth to remove nutrients from water bodies and to
produce biogas is another technically feasible option for the control of water hyacinth, but its environmental
and economic performances are not well understood. This study collected data from an experimental
biogas plant to develop a lifecycle analysis and a cost benefit analysis for the control of water
hyacinth proliferation in a eutrophic lake in China. Comparison was made between the alternative option
of using water hyacinth for biogas production and the current practice of disposing it in landfills. The
results reveal that the biogas option is economically feasible with a positive energy balance. The removal
of water hyacinth to produce biogas can contribute to water quality improvement and GHG emission
reduction whose values, however, depend on the processing scale of the biogas plant. Since both the
current approach and the biogas option can remove nutrients from water bodies, the additional value of
water quality improvement resulting from the biogas option is only possible when the processing scale of
the biogas plant is greater than the amount of water hyacinth disposed by landfill. The emission of
methane deserves attention when water hyacinth is disposed by landfill. The biogas option can respond
to China’s policies on water pollution control, renewable energy development, and energy saving and
emission reduction.