Small reservoirs development has the potential especially the rural to increase water harvesting and storage towards ensuring adequate supply to a wider population, facilitated by the relatively little expenditure required for their construction. Despite their immense significance, developing small reservoirs beyond a certain threshold in a catchment/basin may pose significant adverse effect on the hydrology of that basin. This research therefore sought to explore the impact of small reservoirs and dugouts in the Ghana on hydrology and water allocation in the Black Volta Basin using the Water Evaluation and Planning System (WEAP) and satellite imagery. The methodology involved; analysing hydro-metrological data (1951-2010), demographic data and Satellite Imagery among others. The stream flow gauges for Lawra (Upstream), Bui (midstream) and Bamboi (downstream) were used in analysis. The results showed no significant impact on runoff and about 55.6 B m3 of water flowing downstream untapped. Moreover, unmet livestock and irrigation water requirement range from 1,000 m3 to 6,500 m3 and 40,000m3 to 55,000 m3 respectively, all of which were recorded in the dry season. This implies excess water during the rainy season and some level of scarcity in the dry season. Finally, the study realized the possibilities of developing up to 350 Small Reservoirs by 2040 (under the extreme case of ‘5 times growth rate scenario’) without impacting negatively on hydrology provided the rainfall pattern persist and no significant developments take place in the upstream countries. In conclusion, there is an abundant untapped water resource in the BVB during the rainy season though the basin suffers some level of scarcity in the dry season due to lack of infrastructure to harness the resource at the time of abundance. On this basis, recommendations were made that 5 reservoirs be constructed annually to expand livestock production and dry season irrigation in especially the northern portions of Ghana as it lie along the fringes of the Sahel which is likely to be hard hit by the Climate Change Menace.