Comparative performance of rural water supplies during drought

As rural African communities experience more frequent and extreme droughts, it is increasingly important that water supplies are climate resilient. Using a unique temporal dataset we explore rural water supply (n = 5196) performance during the 2015–16 drought in Ethiopia. Mean functionality ranged from 60% for motorised boreholes to 75% for hand-pumped boreholes. Real-time monitoring and responsive operation and maintenance led to rapid increases in functionality of hand-pumped and, to a lesser extent, motorised boreholes. Increased demand was placed on motorised boreholes in lowland areas as springs, hand-dug-wells and open sources failed. Most users travelled >1 h to access motorised boreholes but <30 min, increasing to 30-60 mins, for hand-pumped boreholes. Boreholes accessing deep (>30 m) groundwater performed best during the drought. Prioritising access to groundwater via multiple improved sources and a portfolio of technologies, such as hand-pumped and motorised boreholes, supported by responsive and proactive operation and maintenance, increases rural water supply resilience.


Hand-pumps -Supplementary Figure 14
Hand-pumps are generally installed on boreholes between 15 and 45 m deep. Some hand pump designs are capable of pumping water from up to 100 m. Deep groundwater (>30 m) is generally more resilient to drought than shallower groundwater [15]. In Ethiopia the Afridev is the common type of hand-pump. Deep well versions of the India Mark II hand-pump are also becoming common in Ethiopia.
The most regular maintenance tasks required for hand-pumps are greasing of the bearings and inspection of the general condition of the pump. More significant (but less frequent) maintenance tasks include rethreading or replacing pump rods and rising mains. These more complex tasks usually require external support, particularly for some hand-pump models which need specialist equipment to remove the rising main and cylinder, including the India Mark II. Seals and bearings are highly vulnerable to wear and need replaced regularly. During drought it may be necessary to extend the rising main and rods, assuming the borehole is of sufficient depth to do so. All sources should be protected from contamination by maintaining the sanitary apron and fencing off the area around the source. Multistage centrifugal pumps are required when pumping from depths greater than 50m.

Motorised boreholes -Supplementary Figure 15
Motorised boreholes must be maintained by a trained caretaker and require effective external support.
Diesel powered pumps require refuelling on a regular basis. Pump oil and water levels should be monitored and replaced when necessary. In some situations fuel might be expensive or scare affecting on-going operation. At regular intervals filters should be cleaned, oil changed and components such as nuts, bolts and the exhaust replaced. Solar powered pumps require regular maintenance of solar panels, including checking for damage and cleaning.
The most frequent problems with motorised boreholes is excessive wear of the moving components and, in the case of electrical and solar pumps, failure of wiring and electrical components.
Submersible pumps may also fail if there is excessive silt or if the borehole runs dry. Thus, the pump should be placed at an appropriate level below the water table and removed regularly to clear silt.
Groundwater levels should be monitored routinely when using submersible pumps to ensure that the risk of the submersible pump running dry is minimised. Pipes associated with the distribution system are often reported as a cause of failure for motorised boreholes and, along with storage tanks, require regular inspection. In general maintenance and repair is more complicated than that required for handpumps and generally requires a higher level of skill and external expertise. For both hand-pumped and motorised boreholes it is essential that spare parts are readily available. where water is stored. The water can then be collected from a tap in the spring box or distributed via a gravity piped system. The most common maintenance tasks for protected springs include ensuring that water is able to flow freely from the spring box and into the drainage system, and ensuring that the area surrounding the spring is clean. If springs become blocked, the protective backfill layers may need to be replaced. Other tasks may include silt removal and leak repair. Most operation and maintenance tasks can be carried out without external support. When protected springs feed gravity water supplies, regular inspection of the pipe network is required to ensure that there is no leakage.

Springs -Supplementary Figure 16
Pipes may need to be repaired and the taps on stand posts may need to be replaced.

Protected wells -Supplementary Figure 17
Protected hand-dug-wells have a much larger diameter than boreholes. Diameters range from a minimum of 0.8 m up to several metres. Hand-dug-wells should be lined, they usually have a wall surrounding the well at the surface and a protective cover. Well depths are relatively shallow (compared with boreholes), but can range from a few meters to over 50 m in some cases. The larger diameter of hand-dug-wells means that, unlike boreholes, they can provide some water storage.
Protected hand-dug-wells may be fitted with a rope and bucket (sometimes on a pulley or a windlass), a hand-pump, or even a motorised pump. Typical maintenance tasks for protected hand-dug-wells include repair of protective coverings and linings, usually by a specialist mason. If water levels fall wells can be deepened, but this is a much harder, and more time consuming, task than extending the pumped depth of hand-pumped or motorised boreholes.

Open sources -Supplementary Figure 18
Open sources include surface water without treatment, unprotected hand-dug-wells and unprotected springs. All of these sources are classified as unimproved. Surface water is highly vulnerable to contamination and is more likely to dry up during drought.

Water trucking -Supplementary Figure 19
Emergency water trucking involves transporting water from another area or catchment into a droughtaffected area for temporary storage or immediate distribution. Water may need to be treated prior to distribution if drawn from vulnerable sources. Emergency water trucking is a high cost drought intervention and typically an intervention of last resort.

Note 2: Overview of the role of mobile maintenance teams
During the period from January to May 2016 UNICEF contracted mobile maintenance teams in four strategic areas to support the Water, Sanitation and Hygiene Committees (WASHCo) in operation and maintenance of hand-pumped and motorised boreholes and electromechanical equipment. The mobile teams were expected to ensure sufficient stock of spare parts supply for electromechanical equipment.
An overview of the roles and responsibility of the maintenance teams is provided below.

Objective
 To sustain water supply provision from existing boreholes by preventing failure in drought affected Woredas.

Tasks
 Conduct a rapid assessment of selected motorised borehole schemes and identify and itemise the following; type of generator, control board and other electrical equipment.
Gather all other relevant information.
 Evaluate conceptual designs of electromechanical equipment installation.
 Support WASHCo's in correct installation of cables, switchboards and generators to ensure stability of electrical supply during power fluctuations.
 Test and maintain electric switchboard control panels, generator and all required cables.
 Maintain/replace all components found to be faulty or at end of serviceable life.  Assist WASHCo's in developing daily maintenance checklists for scheduled maintenance.
 Ensure teams are equipped with the required tools and spare parts at all times.
 Assist in identifying appropriate and high quality spare parts and preparation of technical specifications of spare parts required for operation and maintenance of equipment.
 Train WASHCo's and equipment operators in all procedures required to test and maintain electromechanical equipment to ensure water supply remains functional.
 Ensure transfer of knowledge and skills to WASHCo's and equipment operators for ongoing operation and maintenance of electromechanical equipment.
 Support development and implementation of regional workshop focusing on operation and maintenance of electromechanical equipment.
 Support the development of a protocol for testing functionality of all equipment.
 Submit a monthly report to RWB including the list of activities performed and list of all electromechanical equipment.