Manual Pumping

Water-lifting devices are used to withdraw water from surface water sources (lakes, rivers or reservoirs), groundwater sources (hand dug wells or drilled wells) and underground reservoirs, or to pump water into distribution or irrigation systems.

Hand pumps (also named manual pumps or human-powered pumps) are a type of water-lifting device mainly serving community water supplies that can be operated manually. Human-powered pumps also include foot pumps (HOLDEN & SWANEPOEL 2004) and rope and bucket systems with or without a windlass or shadouf (OLLEY 2008).

Various other forms of lifting devices with external power sources exist: animal, wind and solar powered pumps as well as electric and diesel pumps.

Human-powered pumps are capable of lifting relatively small amounts of water from depths of up to 100 m. They are widely used in places where access to power sources is limited, where financial resources for investment are constrained, and where domestic water requirements are not excessive. Additionally, they are relatively easy to install and rather simple to operate, making them one of the most commonly used and promising water-lifting technologies for rural areas in developing countries (OLLEY 2008).

Human-powered pumps have the potential to improve a community’s local water management system and hence its livelihood significantly. In terms of drinking water supply, hand pumps provide faster, easier and safer access compared to lifting devices with rope and bucket. In terms of irrigation, hand (or foot) pumps can significantly increase agricultural yields: not being dependent on hiring costly and heavy diesel pumps, farmers can irrigate independently whenever optimal for the crops. Equally, women, children and small farmers are empowered (see also gender issues).

On the downside, human-powered pump systems often failed due to a lack of community involvement and adequate maintenance, and due to installation of pumps that were not suitable for heavy usage. The broad recognition of this fact lead to simple low-cost pumping systems (VLOM pumps), which can be operated and maintained by a local community without external assistance, and to the awareness of the importance of community participation in the planning of the pump project from the very beginning and the indispensability of management of maintenance (SKINNER & SHAW n.y.).

Establishing a human-powered pump-based water supply system requires a thorough analysis. When selecting the pump system, a wide range of options should be carefully considered in order to choose the optimal long-term solution. Consult OLLEY (2008): Human-powered Hand-Pumps for Water Lifting (pp.1-2) for a full list of criteria and key questions to answer before selecting pumps.

Until today, hundreds of different human-powered pump systems have been developed based on several mechanical principles. Human-powered pumps make use of one single or a combination of those principles. (BAUMANN 2000):

• Direct lift: Water is physically lifted in a container. E.g. rope and bucket, bailer, Persian wheel.
• Displacement: Water is incompressible. Hence, it can be pushed or displaced (reciprocating technique). E.g. piston pumps, rope pumps, progressive cavity pumps, diaphragm pumps.
• Creating a velocity head: Water can be propelled to a high speed. The momentum produced can be used either to create a pressure or a flow (Rotary technique). E.g. helical rotor, propeller pumps, centrifugal pumps, rebound inertia pumps, jet pumps.

Human-powered pump systems are often categorised in shallow-well (up to 7 metres) and deep-well pumps (above 7 metres).

Based on these human-powered pump types, many different pump models, sub-types and variations are available. All of them have different characteristics (i.e. costs, O&M requirements, health aspects, etc.), and hence suit various different local conditions. For a detailed description of pump models, see MONTANEGRO et al. (2010). For agricultural purposes, many other forms of water-lifting devices exist (see also OLLEY (2008): Human- and Animal-powered Water Lifting Devices for Irrigation).

Capital costs for human-powered pumps are mainly associated with the purchase of the pump, installation, construction of the apron and drainage system, and fencing (HOLDEN & SWANEPOEL 2004). The costs for the pump strongly vary according to the chosen pump type and materials. For most pump types, low-cost options exist making use of locally available material and labour. See BAUMANN (2011): Low-cost Hand Pumps for a detailed description of specific low-cost pump models.

Data from a number of stakeholders in Africa show that many human-powered pumps are actually out of operation, although they were once considered to be robust and simple in maintenance. This represents a crisis of wasted infrastructure investment. The disturbing truth is that installed rural water supply infrastructure is often far harder to keep operational than expected and consequently fails due to poor maintenance before its planned design lifetime (RWSN 2010).

Constructing new water points instead of maintaining existing ones is hardly ever considered to be sustainable. The Rural Water Supply Network (RWSN) argues for the establishment of realistic, long term financial mechanisms and institutional support systems (see also financing (see PPT) and buidling an institutional framework), which can actually lead to adequate operation and maintenance in the long-run and, thus, to a sustainable rural water supply (RWSN 2010).

It can be argued, that in terms of improving water supply systems, external financial support should rather focus on capacity building than on (free) provision of materials and tools. Keeping in mind that self-purchased objects are better taken care of, the idea is to make people pay for water supply systems (see also water pricing and abstraction charges) instead of donating them. However, subsidising may be an option in some context if the project is well organised, implemented and monitored (see also government contributions). As single families frequently are incapable of affording an own well and pump, a form of financial management is required: cost sharing amongst a group of families or community based savings can both make for a sustainable water supply system and a better social cohesion. Alternatively, microfinance can also be an option.

Equally, user involvement during the implementation process (see also community action plan) and communal management of operation and maintenance is vital to enable long-term viability of human-powered pumps. An option for achieving this objective is to nominate a (paid) caretaker who carries out necessary physical tasks such as cleaning the area, lubricating moving parts, tightening bolts and nuts, monitoring the output rate and requesting help for major problems; yet, training of users on how to use the pump properly and general guidance in heath care issues should likewise be part of the caretaker’s remit (ELSON et al. n.y.). 

As for physical maintenance, differing pump types will require a different level of attention and distinctive maintenance tasks (ELSON et al. n.y.). Detailed information on maintenance for the most common pumping systems is found in BRIKKE & BREDERO (2003).

Use of a pump for hand-dug wells brings significant improvement in terms of health. Sealing the opening with a concrete apron and the pump itself effectively prevents contamination from surface (see water source protection). However, some pump types (e.g. rope pumps) may need special attention regarding cleanness as the rope inevitably gets in contact with the outside.