When the community has decided that more and better water is needed, it will be necessary for them to decide what kind of source is possible and will best suit their needs. A well is not always the most appropriate water source in a particular locale. Their goal is to find the cheapest, most reliable way to provide the needed amount of clean water.

Here are the chief potential sources of water listed in their approximate order of preference based on cost, quality of water, need for equipment and supplies:

• Springs - If there are year-round springs nearby, they can usually be developed to supply clean water. This water can often be conveyed through pipes without the expense of pumps or water treatment. Springs can most often be found in hilly or mountainous regions (see Fig. 1-1):

• Wells - Because there is water at some depth almost everywhere beneath the earth's surface, a well can be sunk (using the appropriate technique), almost anywhere. The water that comes into the bottom of a well has filtered down from the surface and is, in most cases, cleaner than water that is exposed on the open ground;

• Rainwater - Collection and storage of rainwater may provide another source where surface and underground water supplies are limited or difficult to reach. Normally, except in the rainiest regions, rainwater will not supply all the water needs of a locale; however, as a supplement, it can be collected from roofs or protected ground run-off areas, and stored in covered cisterns to prevent contamination.

FIG. 1-1. SPRING LOCATION

• Surface water - Streams, rivers, and lakes are all commonly used as sources of water. Although no construction is needed to enable them to supply water, the quality of the water is almost always poor. Only clear mountain streams flowing from protected watersheds could be considered as fit for human consumption.