Amhara, Ethiopia, 2018

Box 4.1, continued

PHOTO B4.1.1

Road-water harvesting as part of the mass mobilization campaign in Amhara, Ethiopia, 2018

Source: © MetaMeta (www.roadsforwater.com). Used with the permission of MetaMeta (www.roadsforwater.com). Further permission required for reuse.

Soil moisture next to the road has increased up to 100 percent in some cases, and farm productivity has risen by 35 percent on average. Moreover, the campaign has produced the added benefits of protecting roads from erosion, limiting flooding and sedimentation, and drastically reducing damage to the landscape.

detailed data collection has enabled analysis of costs and benefits. The road-water harvesting measures are estimated to cost US$1,800 per kilometer and to produce benefits of US$16,879 per kilometer. These benefits include reduced downtime and road maintenance, reduced damage from erosion, reduced flooding and waterlogging, and beneficial use of harvested water.

• The storage capacity of surface reservoirs such as ponds and borrow pits is limited to the size of the basin, but the water is readily available at the surface.

Surface storage systems also suffer losses from evaporation. Chapters 8 and 11 describe the development of borrow pits and ponds. • In contrast, much greater quantities of water can be stored in the soil, in shallow aquifers, or both, provided that the geology of the area is suitable.

The water storage capacity of soil varies according to the soil texture. Table 4.2 compares the storage capacity of different soils.