Lake Bunyonyi, located in Southwestern Uganda, is situated below a vast expanse of hilly terrain. Climate change has made rainfall patterns in the area incredibly unpredictable and thus unreliable for farmers whose livelihood depends on their crops.
Madison Berry, Haven Corsey, Baptiste Debuire, Anthony Kantzabedian, Grace Merkel, Alex Wood
EDNS 491 -Group F20-16-01
Project Review
This project is sponsored by the Global Livingston Institute (GLI), a non-profit organization whose goal is to educate students and community leaders on innovative approaches to international development and empower awareness, collaboration, conversations, and personal growth. In order to help solve the problem of unreliable rainfall, GLI has tasked our team with designing an irrigation system for the farmers of the Lake Bunyonyi community. The main constraints for this project are the cost of the design, lack of resources such as electricity or fuel in the area, the accessibility of materials, constructability, the amount of maintenance required, and the ability to serve the greatest number of community members.
This report details the team's progress in designing a low-cost irrigation system which is tailored to the unique geography and landscape of the community area surrounding Lake Bunyonyi. Initially, our team began the project by doing extensive research on the community, the lake, and existing solutions that could be applied to the Lake Bunyonyi region. Our research, along with conversations with GLI sponsors and local engineers, allowed us to gain a better understanding of the scope of the project and what was needed. This led to the first milestone of the Preliminary Design Report, in which the team presented many possible solutions falling into one of three subsystems: Water Transportation, Water Storage, and Water Delivery. A design matrix was developed with weighted selection criteria corresponding to the project's main design constraints. The steep terrain combined with the lack of electricity and access to fuel in the Lake Bunyonyi region caused our team to focus the bulk our research on various human and solar powered pumps that can be used to transport water from the lake to the model farm. These pumps have an overall output of approximately 10-15 meters. From the design matrix, a mechanical pump seemed to be the best option.
At the beginning of the second semester, GLI stressed the importance of the proposed solution being applicable to all of the members of the community. After learning that the majority of the community members live higher that 15 m in elevation from Lake Bunyonyi, it became apparent that the use of a human powered or solar pump would not be applicable for the bulk of the community due to their limited output. To serve as much of the community as possible, our team collaborated with Team 2 to discuss the possibility of creating different design solutions for community members living at different proximities to the lake. This idea was well received by GLI, and our team elected to take the challenge of creating a design solution for community members living above 15 m in elevation from Lake Bunyonyi, outside the range of the proposed pump solutions. Therefore, the team decided to transition into designing a rainwater catchment system. After analyzing rainfall and crop data and learning that the terrain begins to flatten higher in the hills, the team proposed a combined retention pond and siphon system that could be used to store and transport the largest volume of water at the given price point. However, after water quality and seismic concerns, combined with the fact that the retention pond was not received well by the community, our team decided to discard the retention pond aspect of the design and began researching alternative water storage methods. Originally, this solution consisted of a buried tank and siphon pump to store and transport water to the farmers. The use of a water storage tank was then redesigned to work in tandem with farmers' roofs. A gutter will be fastened onto farmers' roofs which will guide water into a nearby tank. As this rainwater catchment system utilizes available materials and is relatively low-cost, the team has found this to be the final design. This will make water more easily accessible for farmers located up on the nearby hills during the dry seasons. The rainwater catchment solution that our team has designed will allow future engineers working on the project to refine and begin its implementation. An operations and maintenance manual will need to be made to educate farmers and community leaders on how to use and upkeep this system.
Figure 1: Entusi Model Farm, Sponsored by GLI
Application of Design Methodology
As we have seen over the past two semesters, engineering problems never have a direct solution. With the influx of information, the problem has the ability to evolve and change. As a team, what we can agree is the proposed solution in this report is the best solution with the given requirements and will best impact the Lake Bunyonyi community. At the start of this project, the team was excited to learn about the ins and outs of the community and determine how best to fix its current water shortage problem. Since the partnership with GLI has been ongoing, we were fortunate to have a team before we do a project and research which we used heavily to make assumptions in the initial phases of designing our solutions. Using their research allowed us to save time or dive deeper into the information that had found to find clear answers and ask deeper technical questions to our project advisors and the client. Allowing each team member to research their topics allowed the information to be more valued when designing the solutions or asking the question since each one of us was an expert in different fields.
During the initial phases, our team decided to identify restrictions, exclusions, and assumptions for the scope of the project and keep referring to them as we got along so that the client understood clearly where our efforts were going towards and that if changes needed to be made the entire project team was made aware of them. This allowed the team to stay focused for the entirety of the two semesters and designing the best solution. As part of the humanitarian department, this project was heavily focused on making an impact on the individuals who live in the Lake Bunyonyi community, and therefore understanding their needs, style of living, daily life activities, and future made a huge impact on how we approach this problem. As a team, we decided to design a stakeholder map (See figure 2 below) which outlines how a simple change can make an impact on the local economy, environment, and the lives of people. This map allowed the team to understand needs and get the local context of what the solution needs to look like and perform.
