Many important advances have been made in the development of mathematical m
odels for conjunctive water management and reservoir management. However, t
he conjunctive use models that have detailed stream/aquifer system interact
ions have not considered reservoir management rules. Conversely. reservoir
management models have not simulated stream/aquifer interactions in detail.
There is a need for enhanced linking of reservoir and stream/aquifer syste
ms in conjunctive water management models. This paper presents a simulation
/optimization model that integrates linear reservoir decision rules, detail
ed simulations of stream/aquifer system hows, conjunctive use of surface an
d ground water, and delivery via branching canals to water users. The linea
r decision rule is an example of a rule that has been widely discussed in r
eservoir operation Literature and is simple to program State variables, inc
luding aquifer hydraulic head, streamflow, and surface water/aquifer interf
low, are represented through discretized convolution integrals and influenc
e coefficients. Reservoir storage and branching canal hows and interflows a
re represented using embedded continuity equations. Results of model applic
ation to a hypothetical study area under several scenarios indicate that th
e more detail used to represent the physical system, the better the conjunc
tive management. The most detailed representation provides 13% more water t
han the least detailed system.