Evaluation of willingness to pay toward improving water supply services in Sebeta town , Ethiopia

Sebeta town is one of the rapidly growing towns in Ethiopia. Its closeness to Addis Ababa city has attracted industrial, urban development, and population growth. This development has created problems with drinking water shortages in the community. This study aimed at determining the household’s willingness to pay (WTP) amount toward improving water supply services and analyzing the influencing factors of WTP. A contingent valuation (CV) technique was applied in quantifying the households’ WTP and the influencing factors toward the program. The field observations, key informant interviews, and household questionnaire interviews from 250 respondents out of the targeted 280 were employed in collecting field data. Results from CV revealed that 66% of the households were WTP toward improving the water supply services beyond their current monthly water bills. Households were WTP about 20 Ethiopian Birr (ETB) above the average current water bill of 161 ETB. The binary logistic model results statistically demonstrated that independent variables of gender, age, marital status, education level, years in Sebeta, and average monthly income were significantly influencing the household’s WTP at p1⁄4 0.01 and 0.05. This study provides vital hints for further research and baseline information for local administration and communities about the water supply in the area and holistic appropriation of water tariffs in line with government policy.


INTRODUCTION
Access to safe, affordable, and reliable drinking water and sanitation services are fundamental human rights (UNESCO ). Upholding the human right to water is an end in itself and a means for giving substance to the wider rights in the universal declaration of human rights and other legally binding instruments (Zelalem & Beyene ). Securing access to safe water for all helps reduce diseases caused by the use of contaminated water such as diarrhea, cholera, guinea worm, typhoid, and deaths in society. Water is essential for agricultural, household, indus- According to the World Bank (), 75% of water investments in developing countries come from loans, grants, or technical assistance. Furthermore, only 15 countries in sub-Saharan Africa committed to a 2% expenditure on water supply and sanitation from their national budget. In Ethiopia, the external agencies support about 56% of the required funds for water supply programs in the entire country, consequently, the government provides only 44% (Tarfasa ; Anteneh et al. ).
The financial requirements and cost recovery from water-related investments in developing nations are difficult to achieve. The water tariffs are so low in many third world countries since water is classified as a public good, not an economic good. To attract more financing by improving the risk-return ratio of water investments, there is a need to identify sustainable revenue sources for operations and maintenance, preferably through charges to those who benefit from the service (World Bank ; UN ).
Several studies have been conducted to determine residents' participation in water supply projects through willingness to pay (WTP) for water services in Africa. Positive results have been reported. For instance, 95% were WTP toward the management of water supply catchment used by Addis Ababa city (Anteneh et al. ), while 80% were WTP for improved water supply in Marakwet County, Kenya (Kiprop & Sumukwo ).
According to WaterAid, water demand in Sebeta town exceeds the available supplies (Phil & Maric ). Also, the recent study by Tariku () in the area revealed that the current water distribution systems do not supply water in the required quantity. Therefore, this study aimed at determining how community involvement could lead to the improvement of water supply services in Sebeta. The study had two objectives: (1) to determine the households' WTP toward improving the water supply services and (2) to analyse and optimize influencing factors of households to pay for improving the water supply services. This initiative will make sure that water available for domestic, commercial, public, and industrial concerning quantity coverage, consistency, and good quality considering the current and future demand of the area.

MATERIALS AND METHODS
The water supply situation in the study area Sebeta town is one of the Oromia towns and is the capital town of Sebeta Awas district of Oromia special zone surrounding Finfine as shown in Figure 1 Based on the information from the Administrative unit, the current population of the town is 352,505 with an average family size (FS) of 4.8 members. Tariku () noted that water distribution by mode of services in the area was 73.7% of households received water through public tap connection, 24.8% yard connection and 1.5% household connection. The report further disclosed that the average domestic water supply was 20 l/capita/day, which was below the minimum requirement of 80 l/capita/day for towns under category 2 according to GTP-2 (MoWIE ; Temesgen ). Therefore, the water board intends to supplement the existing water supply system of the town, providing safe water, easily accessible, in quantities adequate for drinking, food preparation, personal hygiene, and livestock, at a cost in keeping with the economic level of the communities and through facilities which can be easily operated and maintained.

Procedures of data collection
The study applied various methods of data collection, including reconnaissance surveys, field observations, key informants' interviews, and household surveys. The data were collected for a period of 2 months (February to March 2020).

Reconnaissance survey
A reconnaissance survey was conducted in town for 3 weeks (3 February 2020 to 22 February 2020) from 150 households. Different households were interviewed to capture their perception of the current water supply services.
These interviews were centred on asking households to comment about the drinking water services delivered by Sebeta Drinking Water Enterprises (SDWE) in terms of quality, quantity, and reliability and the number of days water is available at the tap.
Regarding the quality of water delivered at households, 52.8% of the participants ranked that quality is average, 36% good, and 11.2% poor. The study done at household taps in Sebeta by Tariku () reported that the total coliform was below the World Health Organization (WHO) standards. Therefore, this may be the reason for the lowest percentage of quality contentment among the participants.
The quantity of water supplied to the population, and 61.3% of the respondent ranked that the quantity of water delivered was poor due to less availability when needed.
Only 2.0% said that quantity was good. It is revealed in Table 1 that 96.7% ranked the existing water services unreliable. There was dissatisfaction with the existing water services among the residents due to water unavailability. Table 2 reveals the unavailability of piped water in the community for an average period of 3.3 days in a week according to the residents.

Sampling plan
The responses from the reconnaissance survey assisted in determining current water issues in the area and in formulating questionnaires for both qualitative and quantitative contingent valuation (CV) surveys. The survey was done with the help of a graduate research assistant for better data quality. Also, secondary data information obtained from the enterprise's offices and Sebeta town Administration Plan and Economic development office was used to determine the sample size and formulate the questionnaire for household data collection. More information about the town and its community was obtained through a comprehensive review of different documents such as government and international organizations' reports, internet, and journal articles.
The household questionnaire (see Supplementary Material) which was both semi-structured and structured in nature was drafted after an exploratory survey. It was pre-tested to ensure the validity and reliability of data.
Firstly, the 10 administrative Kebeles in town were treated as clusters. The first five clusters (Kebeles) with the highest population were selected for this study. These Kebeles include Sebeta, Alemgana, Walate, Furii, and Dimma. The household sample size for the research was calculated from Gochran () formula as seen in the following equation: where N is the number of households interviewed in the study and Z is the value showing the confidence level at where WTP was a dichotomous dummy variable (where 1 ¼ WTP for the program and 0 ¼ not WTP for the program), i refers to a household, P i is the probability of the households' WTP for the program, β 0 is a constant coefficient, and β 1 , β 2 , β 3 , …, β i , are the regression coefficients of independent variables; X 1 , X 2 , X 3 , …, X i .
The bivariate Pearson correlation was applied to determine the correlation between the independent variables.
This analysis was to find out statistically significant relationships between the variables, strength, and direction of the relationship. Hosmer and Lemeshow goodness of fit was used for the significance of the model as per the following equation (Zoran ): where O g was the total observations of subjects in the gth group, N g is the total observations of event outcomes in the gth group, and π g was the mean estimated probability of an event outcome for the gth group. H L was estimated by a chi-square with the number of groups-2 degrees of freedom. The explanatory variables that were used for analysis in the model included independent variables. These were dummy, categorical, and continuous variables: demographic variables, socioeconomic variables, and other variables depending on peoples' perceptions and practices related to water use. A total of 11 variables were identified as described in Table 3.

Statistical approach
As a result of the first question about the household's WTP toward improving the water supply services in the area, the households were asked whether they are WTP or not with- where i stands for the amount that a household is WTP and n stands for the sample size of households whose WTP is positive.   were young and energetic (Kiprop & Sumukwo ).

RESULTS AND DISCUSSION
According to the survey findings, 76% of the households were married, and the remaining 24% representing widowed,   higher the monthly income of the household, the higher the monthly expenditure.
Analysis of current residents' expenditure on water services

WTP toward the program
The results from the statistical analysis of the WTP toward improving the water supply situation are indicated in Table 6. WTP in this study means the contribution of residents toward improving the current water supply conditions in the area for a period of 10 years. This is different from the current monthly bills that residents are paying for water used.
Out of the 250 respondents, 165 (66%) were WTP toward the improvement of water supply in the area as shown in Therefore, there is a certain level of WTP for improved water services in many African communities.
As shown in Table 6, the study revealed that the minimum WTP amount was 50 ETB/year exclusive of the residents' monthly water bill payment. This value (50 ETB) corresponds to the WTP toward improving the existing water supply conditions in the area for the next 10 years.
The highest WTP was 700 ETB. The average yearly contribution was 241 ETB and the mode payment of 200 ETB, which was the same as the median. The mode revealed that the majority of the residents were willing to pay 200 ETB/year toward the program.
Further analysis of data about WTP toward the program monthly as Table 6 suggests that individuals in Sebeta were WTP on average 20 ETB in addition to their current water bills. The monthly median was 17 ETB. Therefore, the average monthly water bill of the household totals 180 ETB inclusive of payments toward the program of improving water supply. The increment in the average monthly payment for households was about 12.41%. Therefore, there was a promising factor from the residents toward paying for the program of improving water supply services in the area.

Analysis of variables in the binary logistic regression model
The data for the binary regression model were tested for multicollinearity. The correlation matrix of the explanatory variables revealed that data had no problem with multicollinearity. According to coefficients as shown in Table 7, the correlation between the variables was not strong. All correlation coefficients between variables were below ±0.5 which is accepted by many researchers (Patrick et al. ). Therefore, the explanatory variables were appropriate to be applied in the binary logistic regression model.

Analysis of influencing factors about WTP
The logistic regression coefficients (β), standard error correlated with coefficients, Wald, and the significance of the variable are shown in Table 3.
The probability of the households' WTP for the program of improving water supply services in Sebeta is indicated in The relationship between the dependent variable (WTP) and the gender of the household was statistically significant at p < 0.01, with a positive correlation regression coefficient

CONCLUSIONS AND RECOMMENDATION
The study was conducted in Sebeta town, Ethiopia.