IMPACT OF INTENSIFYING IRRIGATION DEVELOPMENT AND IMPLICATIONS FOR SUSTAINABLE WATER RESOURCES MANAGEMENT IN THE WHITE VOLTA SUBBASIN - Sustainable Irrigation Development in the White Volta Sub-Basin - page 195

Impact on groundwater source
Figure 8.7 shows the impact of this scenario on groundwater source. The
results show unsustainable groundwater use in the Anayari catchment, while
that of Atankwidi and Yarigatanga is sustainable. The results imply that, if
irrigation should increase at 10% annually, the unsustainable limit of
groundwater use will be reached before 2025 in the Anayari catchment. This
scenario gives reason for investigating the sustainable limit of irrigation
development considering water resources availability, in particular

groundwater.

Figure 8.7 : Impact of scenario 2 on groundwater storage.
Impact on surface water source
The impact of this scenario on surface water sources was also investigated.
Figure 8.8a shows no significant impact on the Atankwidi streamflow. A
significant drop in streamflow is observed in the Yarigatanga catchment from
May to August when reservoirs are filling up (Figure 8.8b). This reduces the
total annual streamflow in the Yarigatanga catchment by 8.7%.