Innovation of Inverted-well Changes the Concept of Conventional Well Design

Barind Tract of Bangladesh is one of the driest parts of the region where surface water supplies are limited. Large parts of this tract used to be fallow land because there were no major irrigation facilities until mid 1980s. A detailed hydro geological and groundwater survey of Bangladesh was implemented by UNDP in February 1978; Barind was described as follows, “the zone lie on the western Rajshahi known as Barind Tract. Thick clay deposits have been proven by test drilling which indicates that the main aquifer does not exist in the upper 300 m. Therefore groundwater potential is limited to development from relatively thin, fine grained sand zones that appear within the clay sequence. The aquifer is capable of supporting only small domestic needs”. The above mentioned theoretical study result of UNDP is surpassed by the innovation of “INVERTED WELL”. This was the outcome of the actual field trials to meet the local need and match available aquifer conditions that was not suitable for conventional well design. However, desired improved yield from aquifers of limited saturated thickness using inverted wells were achieved. Despite initial surveys which indicated the non-availability of major groundwater resources, till to-date there are around 6625 successful drilled wells are irrigating about 400,000 acres producing approximately one million metric ton of cereals food. Irrigated crop production in Barind area has brought about positive changes in rainfall trend. The average rainfall seems to have increased by 7.3 cm over the last 15 years period, which causes increase in humidity and improvement of the environment.