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 194

the Atankwidi catchment is that the reservoir storage in the Atankwidi
catchment has negligible impact on streamflow and that in the WEAP model
groundwater is unconnected to the surface water.

Figure 8.6: Impact of scenario 1 on streamflow; a) Atankwidi; b) Yarigatanga

8.4.2 The situation in 2025 if irrigation should
have expanded at a rate of 10%/a
This scenario is included based on the consideration that the current rate of
irrigation growth may increase in the near future. The scenario represents
measures that improve the current rate of irrigation expansion in the study
area. In this scenario all existing irrigation systems grew at 10% annually
except large-scale irrigation. Currently there are no future plans to develop
large-scale irrigation schemes and it seems unlikely that there will be such
expansion. The large-scale irrigation was expanded up to the maximum
irrigable area of the Vea Scheme.
Table 8.6 : Input values for 10% annual growth in irrigation at 2025.

Permanent
Shallow
Wells

Temporal
Shallow
Wells

Riverine
Alluvial
Dugouts

Small
Reservoirs

Large
Reservoir

Riverine
Water

tomatoes tomatoes tomatoes rice tomatoes tomatoes tomatoes

Crop

Water abstraction
( mm/season)

640 1550 980 1550 640 1310 900

I rrigation Efficiency 0.73 0.28 0.50 0.68 0.77 0.34 0.49

Water Consumption

88 66 76 85 90 69 77

( %)

Anayari

1581.9 1603.8 0 0 0 2770.2 1749.6

Irrigated
A rea (ha)

Atankwidi

14.6 153.1 0 0 0 729 510.3

Yarigatanga

211.4 21.9 510 340 291.6 10.9 3.6