The plan structure and strategy of investigation are conceived so as to obtain answers to research questions and control variance. The study adapted a descriptive survey design (qualitative and quantitative). Furthermore, data were analyzed qualitatively and quantitatively. Qualitative data were analyzed using descriptions such as documentations, interviews, and observations and open questionnaires, the quantitative data were analyzed using SPSS software 28.0 version. According to Kothari (2019) and Kumar (2018) , mixed research design comprises both qualitative and quantitative methods.

Shukla (2020) defines population as a set or group of all units from which data can be collected, such as individuals, air facts, and events or organizations. Thus, the study population selected all water stakeholders at the Afya Pure Drinking water in Kigoma Municipality to be a representative of the whole population.

The study was conducted at the Afya pure drinking water project located in Kigoma Municipality in Tanzania. The study area was obtained by random sampling procedures, from all names of all water projects in Kigoma Municipality in Tanzania. One piece of paper, named Afya pure drinking water project, was picked up by the researcher and was thus confirmed as the area for investigation.

The study employed three sampling techniques to select subjects, Table 1 . These were random sampling, purposive, and snowball sampling techniques, method of sampling in 2.4 population size.

Random sampling describes that “We write the name of each element of a finite population on a slip of paper, and put a slip of paper into a box or a bag and mix them, and then draw (without looking) the required number of slips for the sample without replacement”. Random sampling method selected water users, clearing and forwarding workers randomly without bias. Similarly on Purposive sampling: the researcher targeted people who were believed to be the key informants for the required information as he/she considered them to be knowledgeable on the issues under the given study based on the set objectives and research questions. Purposive sampling technique was used to select the water engineer, accountant and industrial water manager. Snowballing: snowball sampling was used in selecting water project technicians, water officials, and watchmen at Afya Pure Water Project ( Pace, 2021 ).

The instruments for data collection namely research tools ( Kumar, 2018 ). Data were collected using Four instruments, namely interview, documentation, observation, and questionnaires from both sources of data, likely primary and secondary sources.

Oral Interviews: The study involved the use of questions outlined to ask respondents in order to answer the research questions. The interview schedule was used and responses were recorded per question by the researcher.

Documentation: The researcher asked for written sources of data which in one way or another kept in looking for information and reading written materials such as reports on water projects notices, minutes of meetings, transcripts of speeches, and public records from Kigoma Ujiji related to water projects including the Afya Pure Drinking Water Project and translated its information in a descriptive manner.

Questionnaires: A questionnaire can be defined as a pre-formulated written set of questions to which participants record their answers. The respondents answered the questions on their own. The researcher in this study exercised both closed and open-ended questionnaires based on specific objectives and collected them for analysis.

Observation: The observation requires the use of five sense organs but seeing with your eyes is essential; in addition all observations must be planned based on specific objectives. Using an observation schedule, it was possible for the researcher to observe possible risks at Afya Pure Water Project through interaction with water buyers and company, clearing and forwarding workers, and sellers where he heard spoken words about the water project. The checklist for observation was used.

Reliability refers to demonstrating that the operations of a study can be repeated and still attain the same results ( Kamper, 2019 ). Furthermore, much research conducted by different academicians and organizations possesses both validity and reliability. This study will be a valid and reliable source for decision making because:

The observation check list was produced from specific objectives that were confirmed by academicians in the research field. Questions were straight forward and precise in nature and discussed by peers as well as professionals, academicians, and faculty of project management students and those who have knowledge about research to confirm them. Questionnaires were directly related to the three specific objectives set and its research question from the central objective of the study as a focal point. Furthermore, interview schedules and SPSS 28.0 Software for closed questions were used to produce trustworthy results.

Respondents were asked to state whether they belong to a private, public, or any other category of institution. The results were presented in Table 2 .

Respondents were asked when their respective institution was founded. The researcher was interested in knowing the experiences of the respondents in terms of time. These results show that most organizations were found between 2011 and 2015, followed by 2001 and 2010 years. This implies that respondents had adequate experience and history of water projects in Kigoma municipality. The results were presented in Table 3 .

The study was interested to know the locations of these institutions in order to discover if respondents know water projects around them in Kigoma Municipality. These results showed that majority of these institutions were found in Kigoma Municipality and therefore they have knowledge about water projects in Kigoma municipality such as the Afya drinking water project. The results were presented in Table 4 .

Respondents were asked to state their gender. The researcher wanted to know the contemporary record of the respondents of both male and female population in Kigoma municipality. The grades show that a slight majority were males. The results were presented in Table 5 .

The study was interested in knowing the age database of the respondents in Kigoma municipality. These results show that the majority of the respondents were youths between 20 and 30 years old. The results were presented in Table 6 .

Respondents were asked to state their h level of education in order to know their understanding with regard to risks in water projects, including Afya pure water drinking project. The findings show that degree holders were only 16.4 percent, while certificate and diploma holders were 66.6 percent. This implies that both groups have enough experience and understanding of risks in water projects. The results were presented in Table 7 .

Respondents were asked to state their marital status. The researcher was interested in knowing the rate of participation. The results were presented in Table 8 .

Respondents were asked different research questions concerning the contribution of risk management strategy on water project sustainability, results were presented in Table 9 .

Results presented in Table 9 , show that risk management measures contribute on project sustainability that internal and external risks such as financial risk, reputation risk, and operation risk (workers), operation risks help to achieve water sustainability if controlled properly. The researcher found out that this argument is in line with other researchers, such as Soares et al. (2024) , who stated that risk management strategy on projects sustainability has become significant in many organizations.

Under this objective, the study investigated the risks that hinder project sustainability, respondents were asked different research questions ( Table 10 ). The findings revealed that the majority of the respondents (70.5 percent) confirmed that poor monitoring of risks, unskilled workers on water projects and competition from other water industries such as “Dassani,” affect the market of the pure drinking water industries. The findings were in line with researcher Gachie (2019) , who found that the project’s sustainability includes three pillars, which are the economical pillar, the social pillar and the Environmental pillar. The study convinced that poor monitoring of risk and lack or little social pillar cause poor water projects sustainability. Moreover, the findings from the pure drinking water project responses given indicated that managing competition risk reduces risks in water projects.

Under this objective, the study required to examine the risk management measures that need to be taken in order to achieve water project sustainability. Respondents were asked different research questions, and Results were presented in Table 11 .

The findings revealed that there are risk management measures that need to be taken in order to avoid risks on water projects. Such risk management measures are regular project assessment, community involvement, and monitoring. The finding is in line with the researchers such as Schulte & Knuts (2022) , who indicated that the risk management approach to meet customer needs was to Identify risk, assess and treat risk so as to increase decision for sustainability. Furthermore, other research documents and reports at the Afya Pure Drinking Water Project indicated collaborative effort between the project team and the cost-risk teams to minimize risk. They also insisted that large organizations use formal control systems organized on a divisional basis as an effort to improving control of risks. The study observed that effective monitoring of risks, community involvement, and regular project assessment of water projects help in reaching desirable sustainability.