Changes

Water Portal / Rainwater Harvesting / Groundwater recharge / Sand dam

307 bytes added, 21:22, 18 April 2012

no edit summary

==Suitable conditions ==

{{Climate_change

|drought_text=- ''Effects of drought'': Can dry up; Water yields low. <br> - ''Underlying causes of effects'': Less recharge of aquifer due to less rainfall. Increasing population & water demand; Size of aquifers – e.g. limited sandvolume; Too much silt accumulates behind dam; Wells not sunk deep enough into water table; Incorrect siting creates leaking dams. <br> - ''To increase resiliency of WASH system'': Competent siting & construction; Build sand dam in stages to reduce silt; Soil & water conservation techniques in upper part of catchment; Dig abstraction wells/pipes deeper.

|flood_text= Sand dams require careful maintenance, and immediate repair, as flooding causes hundreds of tons of water to fall over the dam wall and onto the spill-over apron. Flood water may also spill over and erode the wing walls and, perhaps, even over the riverbanks during heavy rains. When determining the dam and spillway height at the selected location, it is very important that the water level and flood line remain below the riverbanks after construction of the dam, or that flooding will not lead to problems up or downstream of the dam. If the flood level is higher than the riverbanks, construction of a dam is not advisable.

Winona

Akvopedia-spade, akvouser, bureaucrat, emailconfirmed, staff, susana-working-group-1, susana-working-group-10, susana-working-group-11, susana-working-group-12, susana-working-group-2, susana-working-group-3, susana-working-group-4, susana-working-group-5, susana-working-group-6, susana-working-group-7, susana-working-group-8, susana-working-group-9, susana-working-group-susana-member, administrator, widget editor

30,949

edits