RIBASIM contains a very strong reservoir operation simulation component used to model single and multi-purpose reservoirs, lakes and storage basins. The following aspects are taken into account:

• Various outlets: main gate, turbine gate, spillway and any number of head sluices.

• Hydraulic characteristics of the reservoir and gates.

• Operation rule curves for flood control, maximum energy production, firm storage, zoning of the reservoir storage and hedging (water rationing) of target releases.

• Hedging based on the target release (demand oriented) or based on the actual storage (supply oriented).

• Time dependent and site dependent operation rules.

• Specific operation based on level control.

• Operation of groups of reservoirs in series and/or parallel.

• Operation based on expected reservoir inflow.

• Hydrological aspects: evaporation losses and rainfall input based on reservoir surface area, seepage losses.

• Hydro-power station characteristics: head - power capacity relation, head - power efficiency relation, discharge – tail level relation, discharge - head loss relation.

• Firm energy demand per time step with a water allocation priority fully taken into account in the water allocation procedure on basin level.

• Computation of reservoir releases based on average reservoir level.

Spillway of Masinga reservoir in Tana river basin (Kenya)

Tungabahdra dam Karnataka (India)

Monitoring station at Ngamoeyeik dam (Myanmar)

Main gate at Ngamoeyeik dam (Myanmar)

Main gate and spillway at new Martil dam (Tetouan Morocco)

Downstrea, pf the Gallito Ciego dam (Jequetepeque Zana, Peru)

Gallito Ciego dam(Jequetepeque Zana, Peru)

Irrigation canal intake downstream of Gallito Ciego dam (Jequetepeque Zana, Peru)