Building a sand dam in Konso

In the Konso region of Ethiopia, WaterAid is helping the local community to construct a sand dam on the Arrayo River in Lehaite kebele, 17 km outside the town of Karat.

Unlike a conventional dam that stores water above the surface, a sand dam is a subsurface structure. The dam in constructed underneath the riverbed and traps and stores water between the pores of the riverbed’s sand.

The benefits of this are great since the water does not evaporate from storage as it would in a conventional dam. Additionally, the sand acts as a natural filtration system making this subsurface water safe to drink.

This type of dam is especially useful in seasonal rivers (rivers that only flow during the rainy season). Seasonal rivers appear to be dry when in fact the riverbed’s sand contains water.

A sand dam’s components are subsurface dam walls (two in this case) and PVC (plastic) slotted pipes that are buried beneath the sand at a level equivalent to the bottom of the dam wall. The slots are covered with gravel before being buried in the riverbed’s sand to prevent clogging.

Water trickles down through the riverbed sand and gravel, into slotted pipes, where it is captured and piped to a storage reservoir tank. From the storage tank it can be piped to various water points.

The water will not need any treatment because of the natural filtration that it went through and will be safer than the local groundwater (which contains high levels of fluoride).

Sanitation

WaterAid is also promoting construction of low-cost latrines to the local community. With guidance from WaterAid, villagers are building various designs of latrine including simple pit latrines and ventilated improved pit (VIP) latrines such as the one pictured, which has been made private by a covering of recycled food aid bags.  

Improving hygiene

To maximize the health benefits of the new water source and latrines, WaterAid is also promoting good hygiene practices such as regular handwashing. Latrines are being constructed with hand-washing facilities such as the jerry can of water attached to the latrine wall seen in the photo above. 

Due to the high cost of soap locally, WaterAid is raising awareness of the fact that ash can also be an effective agent for washing hands.