Study On The Indirect Benefit Evaluation Of Water-saving Tap Renovation In Shanghai Based On Cost-benefit Analysis

Cost-benefit analysis is an effective tool for project evaluation.The benefits of many environmental projects,including water-saving projects,are reflected not only as direct benefits but more as indirect benefits.Based on the cost-benefit analysis method,this thesis focuses on the indirect benefit,and carries out the cost-benefit analysis on the water-saving project of the Shanghai water-saving faucet project,this is valuable in theory and practice.Water-saving project has obvious direct benefits,such as save the cost of water paid by residents,but has more obvious indirect benefits,including of indirect benefits of residents,save repair cost and the cost of alternative water),indirect benefits of enterprise(profits of enterprise,workers' income,employment growth and recycling old tap),environmental indirect benefits(savings on investment in water collection,electricity saving,emission reduction benefits).How to assess indirect benefits and integrating indirect benefits assessment into project decision-making and management is very important for water-saving projects.In the second chapter,the direct and indirect benefits of water conservation are analyzed,and the evaluation methods of direct and indirect benefits are discussed,the significance of assessing the indirect benefits of water conservation is explained from four aspects: ensure the comprehensiveness of the evaluation,reduce project loss at the beginning and ensure the sustainability of water conservation,ensure the scientific decision-making,and make up for the lack of research.This thisis selects the Shanghai water-saving faucet renovation project as an example to carry out a cost-benefit evaluation study.The project is a water-saving project implemented by the Shanghai water administration during the 12 th and 13 th Five-Year Plans.It is an important work for building a water-saving society,implementing the three red lines,building a resource-saving and environment-friendly society in Shanghai.It is typical and representative and can be used as a case for cost-benefit evaluation.The project was launched in 2013 and until to 2017.The cumulative investment was 493,2013 yuan,the total number of renovated taps was 100,000,and the total number of involved families was 52,864.According to the social discount rate of 6% discounted to 2017,the total investment is 5.57 million yuan,and the average single tap investment is 55.67 yuan.The longest service life of faucet is 7 years,therefore,the thesis calculates the benefits of the project until 2023.At the project research stage,2000 questionnaires were issued to investigate and analyze the influencing factors and the transformation of the project implementation.The water-saving contribution of the water-saving faucet in the paper refers to the amount of water saved in the same time and effect during flushing process.The water-saving reconstruction company provided the maximum flow data of the old faucet and water-saving faucet.Through experiments and investigations,it was found that in practical applications,the water flow was about 31% of the maximum flow of the old faucet.And the water-saving faucet has a flow-limiting turbocharger,the flow rate of the spout has been reduced,and a supercharger and a bubbler are installed inside the spout,the daily flow of the residents is about 75% of the maximum flow.According to the above proportions,it is calculated that the water saving amount of one faucet is 1.29L/min during application.In consideration of direct benefits,the direct benefit is the water consumption fee for households saved by the project.After the completion of the renovation project in 2017,the direct benefit discounted value was 3.08 million yuan,the direct benefit-to-cost ratio was 0.55,and the individual faucets gained a return of 30.81 yuan;according to the number of reconstructions,the government was directly subsidizing 58.28 yuan for each household.By 2023,the amount of direct benefit is 6.34 million yuan,direct cost-benefit ratio is 1.14,the average single tap revenue 63.42 yuan,equivalent to 119.98 yuan per household subsidies.Therefore,the direct benefit is obvious,exceeding the investment of water conservation reform.Then further consider and calculate indirect benefits from three aspects: residents,enterprises and environment.After the transformation in 2017,the indirect benefit discounted value totaled 20.23 million yuan,and the cumulative benefit cost ratio was 3.63.By 2023,the discounted value of indirect benefits was 40.67 million yuan,and the cumulative benefit cost ratio was 7.31.The indirect benefit is about 6.47 times of the direct benefit..In consideration of the total project benefits,after the transformation in 2017,total benefit discount value was 23.31 million yuan.The total benefit cost ratio of the project is 4.19 yuan,the average faucet income is 233.13 yuan.By 2023,the total discounted value of the benefit is 47.01 million yuan;the total benefit cost ratio is 8.45,that is,the average faucet income is 470.14 yuan.The thesis analyzes the project's benefit distribution ratio,the average ratio of direct and indirect benefits to total benefits was 13.52% and 86.48% respectively.In indirect benefits,the proportion of sub-items is 96.94% for environmental indirect benefits,2.34% for indirect corporate benefits,and 0.72% for indirect residents,the proportion of each sub-item in environmental benefits is that,the investment cost for water abstraction is 57.9%,the emission reduction benefit is 41.69%,and the energy-saving benefit is 0.42%.Therefore,the indirect benefit of the project mainly comes from environmental benefit,the environmental indirect benefits mainly come from the investment cost for water withdrawal and the investment cost for wastewater treatment.Finally,the thesis discusses the following five aspects: rationality of water saving rate,the indirect benefit classification,the number of questionnaires and survey scope,the value of social discount rate,and the indirect benefits mainly come from saving investment in water withdrawal and investment in sewage treatment.The thesis proposes the following suggestions: promote water-saving renovation projects in other regions of our country and promote indirect benefits evaluation studies.