Rainwater harvesting: Practiced potential for Integrated Water Resource Management in drought-prone Barind Tract, Bangladesh

Present study aims to aid for sustainable management plan of the study area by assessing the potentiality of Integrated Water Resource Management (IWRM) following Bangladesh Water Act (BWA) 2013 and implementing its pilot model through Rain Water Harvesting (RWH) technique as a scientific outcome. The livelihood in the area is at high risk due to drought-situation and expansion of groundwater based irrigated agriculture over the last decade. The stream network and watersheds have been delineated for assessing the potentiality of surface water conservation. The implemented RWH process includes technologically modified dug well recharge and recharge well, runoff water conservation in re-excavated ponds, Kharies along with constructed check dam, and Beels. The annual bimodal distribution of rainfall has high harvesting potentiality during rainy season along with direct runoff amount of 1215 mm. The total harvested amount of rainfall from rooftop, settlement area and cultivated area are 9670869 m(3), 145329128 m(3) and 730431628 m(3) respectively with total amount of 885431625 m(3).The total harvested amount of rainfall and runoff water can fulfill 71% of the total water demand of household and agriculture. After implementation of MAR technique situation started to reverse, that is GWT started rising in response to the augmented groundwater recharge artificially. Analyzed physical, chemical and bacteriological parameters of groundwater quality for pre- and post- MAR technique application stages found suitable for drinking purpose. Before implementation of surface water management scheme water was available for three to five months but after implementation it is round the year. Moreover, the implemented RWH schemes and cross dam, reduce pressure on groundwater withdrawal and provide benefits to farmers particularly women for domestic uses, pisciculture, duck rearing etc., pinpoint '4R' principles of IWRM. Beneficiaries are happy about the inclusiveness and sustainability of schemes with most positive attitude for IWRM practice in study area.