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Water Distribution System
After addressing the issue of water quality, the subject of EWB-Hope's project turned to water quantity. The average amount of time it takes an Nkuv community member to walk to the nearest stream to fill a 15L bucket of water is 5-20 minutes. This journey must be completed multiple times a day in order to have enough water for daily activities - cooking, washing fruits, and cleaning up before meals. The overall goal of the distribution system is to install community tapstands such that no house is more than 150 meters from running water. So far approximately 60% of the population has been serviced.
Because Nkuv is without electricity, the distribution system had to be designed without pumps. The distribution system begins at a river approximately one and a half miles from the village. The elevation difference is great enough to support a gravity-fed water distribution system. In 2008, a diversion dam was built in the river that held three intake pipes for the distribution system. A few sections of pipe were installed to ensure that the intake manifold was functioning correctly, and such was the case.
However, during the rainy season, a buildup of debris, as well as washout downstream caused problems for the intake. During the May 2009 trip, a series of gabions were constructed and installed around the dam in order to prevent recurrences of the problem. The system was designed by several senior engineering students at Hope over the course of the Spring 2009 semester.
The next major component in the distribution system was a water storage tank. A storage tank was necessary in order to maintain a constant supply of water to the community. The tank that was constructed in May 2009 is 10 cubic meters in volume, and capable of sustaining 20L per community member when full.
The pipeline is constructed out of varying sizes of NP-10 pressure piping, similar to PVC. The pipe diameter must be large at the beginning of the system, to allow for enough water to reach the tank. The pipe sizes then get smaller as the supply of water gets smaller as well. This allows for the same amount of pressure be achieved everywhere in the system.
In 2009, enough pipe was laid to service two of the four quarters of Nkuv. These two quarters represent approximately 60% of the population.
The community tapstands are an essential part of the distribution system. Various designs were used in May 2009, as no definite plans existed for how they would be constructed. Nine tapstands were completed in 2009, as well as a tenth temporary tap used for tank construction.
The plumbing of the tapstands was also a consideration. If tapstands near the storage tank receive too much water, there will not be enough water and pressure for taps downstream. In order to combat this, individual globe valves were installed at each tap. The globe valve grants the Nkuv Water Committee the ability to adjust the amount of water individual tapstands receive, so that every tap receives the same amount of water and pressure.