Hand-dug well

1. Hand dug well, unlined

Digging of a well with a small diameter of 0.9 metre diameter

Well fan. Used to bring fresh air in the well especially good when wells are deeper than 10 meters

Rope pump used to pump out water so the well can be dug deeper.

Description

Wells can be dug in almost any kind of soils with simple tools.Advantages compared to drilled wells;

  • In most cases much cheaper- Can be made with tools like a hoePick axe, hammer
  • Skills are locally available
  • Large storage capacity so good inareas with poor aquifers. (Water flowsin at night and taken out in the day)
  • If completed with a well cover, apronseal and pump, hand dug wells candeliver safe water

Disadvantages compared to drilling

  • Can only go in the first shallow aquifers so limited to suitable areas
  • Digging often limited to dry season, waiting for the lowest water level.
  • Shallow water layers are more often contaminated than deeper layers
  • More difficult to make a good seal 

Information

  •  Depth in range of 1  to  30 meters deep and well diameters of 0.8 to 3 meters
  •  In soft layers lining is important to avoid collapsing
  • Water lifted by a rope and bucket, windlass, pumps like Mark 5, Canzee, Rope pump.
  • Cost depends on soil type, well depth and diameter of the well.
  • Cost indication:  50 – 500 US$ (excl. lining, cover, apron, pump)
  • Producers: Local well diggers;  Info at SMART Centres Tanzania and Malawi

2.  Hand dug Well: Lining with bricks, blocks

Lining a well from the bottom up with bricks

A well in sandy soil completely lined with cement blocks. In Malawi mostly Bricks are used

A well lined at the top and bottom with cement and stones

Description

When soil is unstable, (sandy), a well  needs a lining. In other cases often only the top of the well and the lower 1 or 2 meters need lining.

Advantages of lining:

  • No collapsing of the well
  • Safer to go down in the well for cleaning or deepening
  • Functions as a sanitary seal against contamination from around the top
  • Gives a firm base for a well cover

Disadvantages of lining

  • More expensive  than no lining
  • Requires materials which may not be readily available

Information

  • Lining can consist of bricks or cement blocks
  • Bricks need to be of good quality (High temperature firing)
  • Cost depends on material, well depth  and diameter of well
  • Cost indication complete lining;  100 – 500 US$  for a 10 m deep well:
  • Cost indication of partial lining;    50 –  200 US$
  • Producers; Local well diggers

 3. Hand dug well, lined with concrete rings

A well completely lined with cement rings

Lowering a well ring with ropes

Concrete ring at the bottom of a well

Description

A common way for lining is with concrete rings. Wells can be made deeper by digging inside the rings so the rings go down.
Another option is to use telescoped rings (smaller rings which fit inside the larger rings.)

Advantages compared to bricks:

  • – Faster
  • – Can be stronger
  • – Digging can be done inside the rings so the well rings go down by their
    own weight so the well can be made deeper without collapsing of the wall

Disadvantages compared to bricks

  • – Requires moulds for casting
  • – More skills needed
  • – Heavy to lower in well.
  • – More expensive than bricks
  • – In sandy soils, rings can sink by own weight at the bottom of the well and become unstable.
  • – Often impermeable, water comes up from bottom

Information

  • With rings of 0.8 meter diameters, the wells needs to be 1 meter or more
  • Can be prefabricated or made on site
  • Cost depends on length of lining and diameter of cement ring
  • Cost indication for a 10 m deep well: 100- 500 US$ (excl. apron, well cover)
  • Producers: Info at SMART Centre Malawi

 4. Hand dug well: Well heads and aprons

A well with a Parapet , a concrete Well slab plus Apron and Soak away. The Apron and Soak away are to avoid water around the well and infiltration of water in the well

A well cover mounted on a Parapet (well rim). In this case the concrete slab has a metal cover which can be opened when water is needed.

Description

Open dug wells can be improved with a well head. Parts are a well cover (Concrete slab), a Parapet, an Apron and a Soak away.
In general it is essential that the bucket stays off the ground and that hands are clean before touching the bucket.

Advantages compared to an open well

  • – A slab, metal cover avoids contamination from above, windblown dirt, small animals etc
  • – A Parapet and cover prevents people, children from falling in the well, and (rain), splash water flowing into the well.
  • -An Apron and Soak away avoids dirty water from flowing back into the well.

Disadvantages compared to an open well

  • – More expensive

Information

• Well covers, concrete slabs can be in any size and thickness
• Important to keep the bucket off the ground
• Cost depends on well diameter and materials used
• Cost indication for a 1.2 diameter concrete slab: 50 – 200 US$
• Producers: Local masons, well diggers

5. Hand dug well: Well-reducer rings (bricks)

 

A finished Well reducer ring

Making a well reducer ring on a well of 1.2 meter diameter

Description

An option to make the well top fit for a well cover is a Well reducer ring. In this cases made of bricks.

Advantages compared to a concrete slab

– Can be made for any diameter well.
– No need for steel reinforcement
– Ring 1.5 meter made of 1 bag cement
– Includes a seal, so less danger of contamination from outside
– The diameter of theole can be 70 cm so a prefabricated well cover will fit on.
– By making the ring tapered it becomes very strong, so no collapsing
– A tapered ring avoids water flowing back into the well

Disadvantages compared to concrete slab

– For small diameter wells more expensive
– Not a known technology yet, requires training

Information

• For wells with any diameter. Preferred inside diameter 70 cm but can be any size
• Can be combined with a prefabricated well cover and mounted with a Rope or other pump
• Cost depends on diameter, available materials
• Cost indication : 50 – 100 US$ (excl. cover for the pump)
• Producers; Info at all SMART Centres

6. Hand dug well: Well reducer rings (blocks)

Well reducer ring made with tapered cement blocks

The blue items are moulds made of sheet metal used to make the cement blocks.

The white parts are the Cements blocks
With a length of 40 cm

Description

If burnt bricks are not available or more expensive than cement blocks, a reducer ring can also be made of tapered cement blocks.

Advantages compared to bricks:

– An option where bricks are expensive
or low quality
– Can be longer so a longer overlap is possible. For instance on a well of 1 meter only one ring of blocks is needed to reach an inside diameter of 70 Cm

Disadvantages compared to bricks

– Requires moulds for blocks
– Maybe more expensive
– Not a known technology yet, requires
training

Information

• Blocks can be made on site or be prefabricated
• Blocks are 40 cm long and 5 cm thick.
• With each ring the diameter can be reduced with 30 cm
• Cost depends on the diameter of the well. (either 1 ring, 2 rings or 3 rings)
• Cost indication: 60 – 120 US$ for well diameter 1 meter: (excl. cover)
• Producers: Still in development.

7. Hand dug well: Prefabricated well cover

Prefabricated well cover with bolts for mounting a Rope pump

A well cover mounted on a hand dug well with a well reducer ring. The pump is mounted with bolts on the prefabricated well cover. Partly ready. Requires apron and soak away.

Description

If a Rope pump will be installed and the well has a Well reducer ring, the well cover can be small in diameter (0,8Meter) and can be prefabricated in the pump or other workshop.

Advantages compared to on site production well cover

  • – In most cases cheaper
  • – Better quality, easier to control
  • – Fast installation. Pump and cover can be installed in one hour. No need to
    wait until the cement is dry and no need to come back for installation of the
    pump

Disadvantages compared to on site production

  • – Depending on way of transport, maybe heavy to transport

Information

    • Well cover diameter is 0.80 meter. Well cover weight 25 – 40 kgs
    • Cover has a 4 inch pipe for both pump pipe and return pipe so all maintenance and repair can be done via this 4 inch pipe
    • Well cover and well reducer ring sealed with cement so no water flows back into the well
    • Cost indication 30 – 60 US$ (excl. pump)
    • Producers: Info at all SMART Centre
JasminaHand-dug well