==Construction, operations and maintenance==
====Plan the pond====
Pond size (and therefore dam height) can be decided according to water demand, evaporation & seepage losses, length of critical period and average stream flow according to the following:
* Determine water requirement (R litres/day)
* Estimate area of reservoir (A m2), evaporation & seepage losses (E mm/day) and therefore the volume losses per day (A x E litres/day)
* Estimate length of critical period during which stream flow is less than water requirement & losses (T days) and when water requirements are met by using water from reservoir
* Estimate average stream inflow during critical period (Q litres/day)
* Calculate effective storage required (S litres) = (R + AxE – Q) x T
* Site should be then surveyed to estimate area (A m2) of reservoir for different values of normal water level (D) – this will give reservoir capacity which should be greater than storage required (S) to allow for a safety margin. Reservoir capacity can be estimated by the following: (length x width x maximum depth) / 6.256
* Height of dam will be D plus 1m (for flood level & safety margin)
====Build the pond====
Smaller scale dams owned privately might have more chance of success in terms of the participation in construction and maintenance processes.
* Small dams tend to fail much more frequently than larger dams, and this seems due to poor siting and design, lack of design, poor construction techniques and lack of maintenance. One example in Sudan demonstrates this where breached dam embankments were attributed to a gross underestimation of the runoff volume, as well as poor overall design. Proper design, construction and maintenance are therefore important. The following are guidelines used for hillside dams maximum 3m high, where water is retained by an embankment. For heights over 3m, other guidelines are available.