| Water purification, distribution and sewage disposal for Peace Corps volunteers |
|Section 3: Planning the distribution system|
WATER DISTRIBUTION SYSTEMS
PLANNING THE DISTRIBUTION SYSTEM
One of the most difficult and baffling problems in the planning of a small water-supply system for a rural community is the lack of criteria upon which a design can be based. The volunteer needs answers to such questions as: "What increase should be allowed for future population growth?") "Should provision be made for periods of peak demand?"; and "What about storage?" Such technical questions have been thoroughly studied and standardized in textbooks dealing with design of water supplies for urban communities. However, for most rural, underdeveloped areas of the world, reliable design guides have not yet been established. Furthermore, certain elements of design are matters for local decision, depending on geography, local economy, custom, and other factors.
The experience gathered from several rural water-supply programs has been analyzed and is summarized below to serve only as a broad guide. It is realized that there are wide variations in water-supply practice throughout the world and that every designer should not apply blindly the criteria listed here; instead, you should be able to make a critical analysis of the conditions and problems of the area under study and should develop applicable criteria. In so doing, you should contact the health administration of the area concerned with a view to consulting the minimum standards for design and construction which this administration may have issued through its public health engineering division.
There is, however, general agreement on the following fundamental point; in the design of rural water-supply systems, primary consideration should be given to the protection of the quality of the natural water selected, since treatment should be considered only as the very last resort. This requires the incorporation in the design of necessary sanitary safeguards, beginning with the proper location of intake structures and pipes. Except, in unusual circumstances, other engineering and structural elements should be conceived around this need.
Before beginning the actual construction of a village water system, a well defined plan needs to be drawn. The water system, when completed, will be the result of a large commitment from all the local people, both in finances and labor. To be sure that the system is what they want and need, careful planning is a requisite. In planning the water distribution system, there are seven major categories to be defined.
1. Existing Facilities: What already exists? How good is it? Can it be made part of the overall system?
2. Size and Nature of the Community? How many people will be users? How are they distributed? What customs or traditions do they have that must be considered in the overall plan?
3 System Capacity: How much water is needed dally? When are the peak demands?
4. Water Source: What type of source will provide the most economical and satisfactory water for the system?
5. Proposed System: Location of facilities, pipes, outlets, etc.
6. Site of Proposed Facilities: An outgrowth of the proposed system, What problems will there be in obtaining the land needed for the proposed facilities?
7. Financing: How will the materials be obtained? Will this project be financed by government, cooperatives, on a cost basis, etc.?