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 198

Table 8.8 : Current surface water irrigation and potential expansion up to 2%
of catchment area

Surface Water Irrigation Technologies

Catchment Irrigation

Technology

Current
Area
(Km 2 )

Potential
For
Expansion

Limiting Factor(s)
for Expansion

Additional
development
(quantity)

Projected
Area (Km 2 )

Small
Reservoirs

2.17 Low Financial, Social and

environmental

66 9.37

Anayari

Small
Reservoirs

0.02 Low Financial, Social and

environmental

53 5.50

Atankwidi

Small
Reservoirs

0.29 Low Financial, Social and

environmental

none 0.29

Riverine
Water

0.40 Low Excess water from

Vea Irrigation
scheme

Scale Factor
of 3

1.20

Yarigatanga

Large
Reservoir

1.45 unplanned none

Figure 8.9: Impact of scenario 3a on streamflow; a) Atankwidi streamflow; b)
Yarigatanga
Figure 8.9 shows a reduction in streamflow due to the upscaling of irrigation
development according to Tables 8.7 and 8.8. From the model results, annual
streamflow drops of 7.5% and 8.5% are observed in the Yarigatanga and
Atankwidi catchments, respectively. Since base-flow in the study area is
negligible (Martin, 2006), the reduction in streamflow estimated by the
model is basically due to the upscaling of surface water irrigation. The
impact of groundwater on streamflow will be estimated using simple water
balance analyses (see next section).