Ninety percent of the rainfall in different regions of Myanmar are monsoonal. Precipitation varies country-wide, furnishing (200) inches per annum in the south and western coastal strips, (80) to (120) inches in the delta, (50) to (120) inches in the north and eastern hilly regions, and dropping to below (30) inches in central Myanmar.

As a result of the difference in precipitation, moisture availability for plant growth is not sufficient in certain regions, even during the rainy season and during the dry season the problems become more acute.

It is accordingly obvious that successful crop production is dependent on availability of stored water from rivulets and ponds.