Nowadays, water pollution has become a major factor restricting social development. To address this, the government has issued a series of policy documents to control water environmental pollution and achieved certain results. However, on the whole, the prevention and control of the pollution of water environments requires a large amount of capital investment, but the corresponding results and benefits are not significant. Hence, this paper takes Shanghai, Nanjing, Hangzhou, and Hefei as examples to study the financial cost-effectiveness of the governance of urban water environments from the two dimensions of time and space. It is concluded that the cost of water environmental treatment has a negative effect on the comprehensive benefit of environmental treatment in the region in the short term and a positive effect in the long term, which indicates that water environmental pollution treatment is a work that needs to be adhered to for a long time, and long-term planning is also needed for cost input. On this basis, strategies to improve the cost efficiency of water pollution treatment are presented.
There may be missing or unmeasurable control variables, which will lead to the random error term including the influencing factors of environmental benefit.
The cost of the governance of water environments has a negative effect in the short term and a positive effect in the long term.
It is also necessary to optimize the top-level design of water environmental pollution control in the lower Yangtze River Economic Belt.