Abstract:
In Bangladesh, surface water was the principal source for drinking water ever upto
recent past. However, during the recent decades, due to the intensive development
programs, the ground water is utilized for drinking purpose in most rural areas.
Unfortunately, recent investigations have demonstrated almost countrywide occurrence
of high arsenic levels in the tubewell water. Today, Bangladesh seems to be one of the
most arsenic affected countries in the world, Bangladesh is a tropical country and
receives heavy rainfall during the rainy season. In the present context, rainwater
harvesting is being seriously considered as an alternative option for water supply in
Bangladesh.
The objective of this research is to study the potential of the rainwater harvesting
system in Bangladesh. Ninety seven percent of rural population has access to tubewell
water and ground water is still good for all type of uses except drinking. Therefore, the
main emphasis is given on the rainwater harvesting as a source of drinking water. The
research includes a literature review on rainwater harvesting systems, costs and water
quality.
In performing the study, frequency analysis is undertaken on annual rainfall data from
25 stations of Bangladesh Meteorological Department (BMD). The most appropriate
probability distribution for each location is determined and used to estimate the
reliability of the system of that location. Based on this, design curves are developed to
estimate the reliability of the system for any consumption rate at different areas in
Bangladesh.
Mass curve analysis is used to deterinine required storage volumes for every location.
Based on statistical analysis of required storage volumes, design curves are developed
for estimation of storage tank volumes covering the need for drinking water of different
household sizes. These curves can be applied at field level by non professionals.
