In this article a control model that can be used to determine the depe
ndable power capacity of a hydropower system is presented and tested.
The model structure consists of a turbine load allocation module and a
reservoir control module and allows for a detailed representation of
hydroelectric facilities and various aspects of water management. Alth
ough this scheme is developed for planning purposes, it can also be us
ed operationally with minor modifications. The model is applied to the
Lanier-Allatoona-Carters reservoir system on the Chattahoochee and Co
osa River Basins, in the southeastern United States. The case studies
demonstrate that the more traditional simulation-based approaches ofte
n underestimate dependable power capacity. Firm energy optimization wi
th or without dependable capacity constraints is taken up in a compani
on article [Georgakakos et al., this issue].