[[Image:{{Language-box|english_link=Water Portal / Rainwater Harvesting / Surface water / Sump intake icon.png|right]]french_link=Prise d'eau avec puisard |spanish_link=Toma de pozo | hindi_link=वाटर पोर्टल / वर्षाजल संचयन / सतही जल / संप इनटेक |malayalam_link=Coming soon |tamil_link=Coming soon | korean_link=Coming soon | chinese_link=集水坑引水口 |indonesian_link= Lubang Asupan Penampungan | japanese_link=汚水だめの取水}}
[[Image:intake icon.png|right|80px]]In a '''sump intake ''' (a deeper intake than other intakes), water from a river or lake flows through an underwater pipe to a well or sump from where it is lifted, usually into the initial purification stages of a drinking-water system. The inflow opening of the underwater pipe is located below the low-water level and is screened. A well provides a place for sedimentation to settle and protects the pump against damage by floating objects. To facilitate cleaning, two sump intakes are sometimes built for one pump.
A well-type pump may be set in a sump, with the inlet pipe through the river bank. In a simple intake, the pipe can be surrounded with a protective stone covering. In target intakes a pier can be used to provide access to the intake, for instance to operate a valve or clean the screen. The pier also provides some protection, and could be fitted with a bar screen to exclude debris from the intake. A duplicate inlet pipe, sump and pump may be provided to make it easier to de-silt the sump and maintain the pump.
===Suitable conditions===
On the banks of rivers and lakes.
Sites on the inside of bends should be avoided, to reduce sediment deposition and inflow.
Problems can arise if the river bed is unstable (for example, gravel), or the river is very shallow at low flows. It can be difficult to set the intake level to be safe from silting up during floods, but still able to abstract water at low flows. A [[Water Portal / Rainwater Harvesting / Surface water / Tyrolean weir | Tyrolean weir]] can assist with this or a [[Water Portal / Rainwater Harvesting / Surface water / Floating intake | Floating intake]] can be used.
===Resilience to changes in the environment===
====Drought effects on cement====
'''Effects of drought''': Badly made concrete or cracked linings (e.g. in tanks, dams, waterways, wells, and other structures). <br>
More information on managing drought: [[Resilient WASH systems in drought-prone areas]].
===Construction, operations and maintenance===[[Image:SumpIntakeDiagram.JPG|thumb|right|300px200px|Sump intake diagram. Click image to zoom. <br> Drawing: WHO.]]
Operation is usually carried out by a caretaker. The sump must be checked daily for sufficient water inflow; any debris obstructing it must be removed, and any damage repaired. Most of the maintenance will be to the pump. The intake itself needs some cleaning and de-silting. If it caves in, or if the river or lake bank erodes, repairs have to be made. A sump inlet does not require special organizational arrangements.
[[File:SumpIntakeOM.jpg|thumb|centernone|400px500px|Operation and maintenance roles. Click chart to zoom in. Chart: WHO.]]
====Potential problems====
— a sump intake is unsuitable for rivers that are very shallow or that have low flow rates.
==Costs=Manuals, videos and links===* [http://www.samsamwater.com/library/TP40_11_Surface_water.pdf Surface water intake and small dams]. Chapter 11. Revised by Nhamo Masanganise.
==Manuals, videos, and links== Acknowledgements==Acknowledgements==* Brikke, François, and Bredero, Maarten. ''[http://www.googlewashdoc.cominfo/docsearch/title/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC0QFjAB&url=http%3A%2F%2Fwww.who.int%2Fwater_sanitation_health%2Fhygiene%2Fom%2Flinkingintro.pdf&ei=cwJpT-zaO-OiiQKCst2rBw&usg=AFQjCNEWOQhTgF3a7lzhuw5OA2KmbVGxcA&sig2=Rt2EURUyGVqDcwFg6p0xAw 117705 Linking technology choice with operation and maintenance in the context of community water supply and sanitation: A reference document for planners and project staff]''. World Health Organization and IRC Water and Sanitation Centre. Geneva, Switzerland 2003.* [http://www.bvsde.paho.org/eswww/tecapropiada/otratec/waterlin/tb22.pdf Waterlines: Technical Brief 22] or ([http://www.washdoc.info/docsearch/title/116333 alternative link]).