Akvopedia-spade, administrator
3,247
edits
Changes
no edit summary
==Suitable conditions==
* Locate in natural runoff areas
* Soil in vicinity needs to have sufficient infiltration capacity.
- Unclear land tenure can result in ownership of the structure
}}
==Resilience to changes in the environment==
====Drought====
'''Effects of drought''': Lower crop yields.
'''Underlying causes of effects''': Less water to crops.
'''To increase resiliency of WASH system''': Drought-resistant & fast-growing crops; Diversify livelihoods of farmers.
====Floods====
With intense rain events, see if the check dam is still managing flow from its center. If it is not, the dam could crumble, rendering it ineffective, and will need rebuilding.
==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.
'''Specific advice''':
[[Image:CementCheckDam.jpg|thumb|right|300px|Drawing: [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CFkQFjAB&url=http%3A%2F%2Fwww.saiplatform.org%2Fuploads%2FModules%2FLibrary%2FSAI%2520Technical%2520Brief%25205%2520%2520The%2520Importance%2520of%2520Soil%2520to%2520Water%2520Use.pdf&ei=gf91T6GYJ-jWiAK7zuGnDg&usg=AFQjCNFDyR4mjTVCcvvTt-9v4OrxAZQfDA&sig2=iMzgbW0eK395na_V_YA4Kw ''Water Conservation Technical Briefs''.] SAI.]]
[[Image:WoodenCheckDam.jpg|thumb|right|300px|Cross section of wooden check dam. Overtop "pour spout" must be included. <br> Drawing: [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CFkQFjAB&url=http%3A%2F%2Fwww.saiplatform.org%2Fuploads%2FModules%2FLibrary%2FSAI%2520Technical%2520Brief%25205%2520%2520The%2520Importance%2520of%2520Soil%2520to%2520Water%2520Use.pdf&ei=gf91T6GYJ-jWiAK7zuGnDg&usg=AFQjCNFDyR4mjTVCcvvTt-9v4OrxAZQfDA&sig2=iMzgbW0eK395na_V_YA4Kw ''Water Conservation Technical Briefs''.] SAI.]]