__NOTOC__{{Language-box|english_link= Traditional hand-dug wells | french_link= Coming soon | spanish_link= Coming soon | hindi_link= Coming soon | malayalam_link= Coming soon | tamil_link= Coming soon | swahili_link=coming soon | korean_link= Coming soon | chinese_link=传统人工钻井 | indonesian_link= Coming soon | japanese_link= Coming soon }} [[Image:traditional hand dug well.png|right|80px]][[Image:StoneLiningHandDugWell.jpg|thumb|right|350px200px| Placing a stone lining in a hand dug well. Chiapas, Mexico.Photo: [http://www.flickr.com/photos/aamv/366661815/ The Maya Village Project.]]]These are shallow wells which draw water from a natural aquifer or man-made aquifer, e.g. near [[sand dam ]]s or around [[ponds]], but which are not located inside a riverbed. It can include wells that are far from a river, or wells that receive water from shallow aquifers hydraulically connected to the river. Sometimes the holes dug are very large, allowing people and sometimes animals who are able to walk into the well to where the water is located. <br>
Water extraction can be done with [[Handpumps]] or [[Small and efficient motor pumps]]. A bucket and rope can be used but risk of contamination increases. In such a case, household water treatment should be advocated.
===Suitable conditions===
* Layers of sand and gravel tend to provide good locations for wells and boreholes. Other good locations are in weathered rock in granite areas, along the edges of valleys in mountainous areas or in a river valley where there may be sandy deposits under the banks.
* Care should be taken to avoid siting wells in perched aquifers (shallow aquifers with limited recharge capacity and water storage).
source of contamination (e.g. latrine) to the water intake (screen) needs to be sufficient so as to pose a “low” to “very low” risk – this translates into a minimum of 25 days of potential travel of pathogens in the ground. Travel time is influenced by porosity, hydraulic conductivity (permeability) and hydraulic gradient. For medium size sand with an average porosity, the distance equivalent to 25 days is around 30 metres, but this can increase to over 100 metres for coarser sediments. However, the distance from contamination to water intake can reduce significantly where the screen intake is at a sufficient depth – this is due to greater variation of aquifer properties in vertical directions than lateral, meaning that a borehole with handpump could be placed very close to a latrine with low risk. However, screen depth must increase with increased extraction rate.
{{procontable | proborder="1" cellpadding="5" cellspacing="0" align="center"|-! width="50%" style="background:#efefef;" | Advantages! style="background:#f0f8ff;" | Disadvantages|-| valign="top" | - Manual access, that can be deepened or maintained easily at a later date
- Can be privately owned/operated <br>
- Circumstances which make the construction of large diameter wells necessary:
# Where the aquifer (water storage) is of extremely low permeability
# Low cost labour and skills are available
| convalign= "top" | - Greater effort and longer construction time
- Greater safety hazards during and after construction <br>
- Difficulty in preventing contamination <br>
- Can be difficult to sink to required depth especially in areas of flowing sand <br>
- Water levels in the aquifer can drop over time, resulting in possible mining (where aquifer is compressed and cannot hold water any longer afterwards)
|}} ===Resilience to changes in the environment=======Drought===='''Effects of drought''': Can dry up perched aquifers; Groundwater levels dropping in perched aquifers. '''Underlying causes of effects''': Less recharge of aquifer due to less rainfall; Increasing population & water demand; Size of aquifers – e.g. perched aquifers will be used up faster; Wells not dug deep enough into water table. '''To increase resiliency of WASH system''': Avoid perched aquifers; Dig wells deeper – de-water well during caissoning within the water table; Allow for subsequent deepening by using telescopic lining; Dig wells during the latter half of the dry season; Recharge aquifer through Managed Aquifer Recharge (MAR) boreholes; Jet in the bottom of the well to provide a means of faster recharge; Increase flow by use of porous concrete or perforated pointed steel pipes driven horizontally into the aquifer. More information on managing drought: [[Resilient WASH systems in drought-prone areas]]. ===Construction, operations and maintenance==='''General advice on cement''': A common cause of cracks in structures and linings (e.g. in tanks, dams, waterways, wells) is errors in mixing and applying the cement. First of all, it is important that only pure ingredients are used: clean water, clean sand, clean rocks. The materials have to be mixed very thoroughly. Secondly, the amount of water during mixing needs to minimal: the concrete or cement needs to be just workable, on the dry side even, and not fluid. Thirdly, it is essential that during curing the cement or concrete is kept moist at all times, for at least a week. Structures should be covered with plastic, large leaves or other materials during the curing period, and kept wet regularly.
==Construction, operations and maintenance=='''Specific advice''':[[Image:HandDugWelldiagramtelescopic lining.jpg|thumb|right|350px200px|Hand-dug well with telescopic lining. Diagram: Watt, S.B.; Wood, W.E. (1979) Hand Dug Wells and their Construction. IT, London, UK.]][[Image:HandDugWellConstruction.jpg|thumb|right|350px200px|Construction of hand dug well at Kulala Kebele, Dera Woreda, Amhara Region, Ethiopia. Photo: [http://www.flickr.com/photos/waterdotorg/4923124025/ Water.org]]].
The basic elements of a hand-dug well are illustrated in Figure 5.3. The three main elements are: <br>
A. '''The Well Head''' - this is the part of the well which is visible above the ground. It generally consists of a protective apron and a superstructure which depends on the type of extraction system in use. <br>
Simplify construction methods while getting a more robust end product in a safer fashion. Using lining & telescopic lining has the advantage that heavy lifting equipment for pre-cast rings is obsolete while procedures are inherently safer. Lining is made using one-skin moulds that hold concrete against the dug wall of the hole, while the telescopic shaft can be made from curved blocks built onto a foundation cutting ring – the blocks can be extended as and when necessary.
===Costs===Hand-dug wells can provide a viable alternative to unhygienic, unprotected sources while avoiding the capital and maintenance costs associated with sophisticated drilling programmes or reticulated pumped systems. A range of lining types and water lifting technologies can be chosen to match the financial and management capacity of the participants in the water supply process. ===Field experiences===The following projects are utilizing hand dug well techniques. <br>{{RSR_table|1image=project 1365.jpg |1link=http://rsr.akvo.org/project/1365/ |1project#=1365 |1project name=Facilities Ibbagamuwa school Sri Lanka ||2image=project 1349.jpg |2link=http://rsr.akvo.org/project/1349/ |2project#=1349 |2project name=Safe water <br>for Wajir ||3image=project 822.png |3link=http://rsr.akvo.org/project/822/ |3project#=822 |3project name=Urban WASH II <br>in Monrovia ||4image=project 894.png |4link=http://rsr.akvo.org/project/894/ |4project#=894 |4project name=Senjeh Well <br>Restoration ||5image=project 896.png |5link=http://rsr.akvo.org/project/896/ |5project#=896 |5project name=Gboto Well <br>Restoration |}}{|style="border: 2px solid #e0e0e0; width: 60%; text-align: justify; background-color: #e9f5fd;" cellpadding="2"|- style="vertical-align: top"|[[Image:akvorsr logo_lite.png|center|60px|link=http://akvo.org/products/rsr/]]|- style="vertical-align: bottom"|[[Image:project 922.png |thumb|center|140px|<font size="2"><center>[http://rsr.akvo.org/project/922/ RSR Project 922]<br>WaterAid Rural <br>WASH Project</center></font>|link=http://rsr.akvo.org/project/922/ ]]|[[Image:project 933.png |thumb|center|140px|<font size="2"><center>[http://rsr.akvo.org/project/933/ RSR Project 933]<br>Accelerating Sanitation and Water for All 1</center></font>|link=http://rsr.akvo.org/project/933/ ]] |[[Image:project 1330.png |thumb|center|140px|<font size="2"><center>[http://rsr.akvo.org/project/1330/ RSR Project 1330]<br>WASH services & capacity building Liberia</center></font>|link=http://rsr.akvo.org/project/1330/ ]] |}
==Field experiences==<br>
==Reference manuals=Manuals, videos, and links===* [http://www.googleindiawaterportal.comorg/articles/url?sa=t&rct=j&q=&esrc=s&source=web&cd=12&ved=0CJUBEBYwCw&url=well-revival-effort-sees-many-other-benefits Well revival effort sees many other benefits] A community drive to revive wells in Mokhla talab near Udaipur results in water security for longer periods of time as well as making leaders out of women.* [http%3A%2F%2Fwww://www.watersanitationhygieneindiawaterportal.org%2FReferences%2FEH_KEY_REFERENCES%2FWATER%2FHand%2520Dug%2520Wells%2FHand%2520Dug%2520Shallow%2520Wells%2520%28SKAT%29/articles/experiments-community-wells Experiments with 'community wells'] Mobilized farmers in Dhule, Maharashtra, show how communities can use groundwater as a common resource in an organised and collective manner.* [http://www.pdf&ei=Uw2GT9TePISniQKbybXyDw&usg=AFQjCNFPJuGGwETWtNwuAwM91A7igDOi_A&sig2=kzoKjAcpe0wH8Yrbwrural-Xwater-NA supply.net/en/resources/details/256 Hand dug shallow wells (SKATSkat)]. Includes construction information plus covers lining options. Also a good section on environmental, social, and cultural considerations. Swiss Centre for Development Cooperation in Technology and Management.* [http://www.rural-water-supply.net/en/implementation/hand-dug-wells Hand Dug Wells] section of the Rural Water Supply Network website * [http://www.consallen.com/welldigging/ Consallen]. An excellent guide to a relatively safe method of digging hand dug wells by the highly experienced British Drilling Company.
* [http://www.fao.org/docrep/X5567E/x5567e06.htm#5.%large%diameter%wells Large Diameter Wells]. An excellent but slightly outdated summary of hand dug wells by Koegel, made available by the UN FAO.
* [http://www.clean-water-for-laymen.com/hand-dug-wells.html Hand Dug Wells and Other Manual Methods to Dig a Well Have Been in Existence for Thousands of Years]. Compares different methods of digging a well, includes hand-dug method.
* Old style of excavated wells in India: [http://www.greatmirror.com/index.cfm?navid=169 India Themes: Irrigation 1: Ancient Methods.]
===Acknowledgements===* CARE Nederland, ''Desk Study : [[Resilient WASH systems in drought -prone areas.'' ]] October 2010.* Collins, Seamus, [http://www.googlerural-water-supply.comnet/en/resources/url?sa=t&rct=j&q=&esrc=s&source=web&cd=12&ved=0CJUBEBYwCw&url=http%3A%2F%2Fwww.watersanitationhygiene.org%2FReferences%2FEH_KEY_REFERENCES%2FWATER%2FHand%2520Dug%2520Wells%2FHand%2520Dug%2520Shallow%2520Wells%2520%28SKAT%29.pdf&ei=Uw2GT9TePISniQKbybXyDw&usg=AFQjCNFPJuGGwETWtNwuAwM91A7igDOi_A&sig2=kzoKjAcpe0wH8Yrbw-X-NA details/256 Hand dug shallow wells (SKATSkat)]. Swiss Centre for Development Cooperation in Technology and Management. 2000.