Superpositioned analytic functions are used to efficiently and accurat
ely model ground-water flow fields containing thin barriers such as sl
urry walls and sheet-pile walls. Barriers are modeled as a series of s
traight-line segments strung together to create irregularly shaped ope
n or closed boundaries with zero thickness. The complex analytic funct
ions employed provide perfect continuity of flow across the boundary w
hile approximating normal flux boundary conditions along the boundary.
Along an impermeable boundary the normal flux is specified as zero, a
nd along a resistant (leaky) barrier the normal flux is proportional t
o a specified resistance parameter and the potential difference across
the boundary. solution of a given flow problem requires solving a sys
tem of equations with one equation per boundary corner. These equation
s are linear for impermeable boundaries and for resistant boundaries i
n confined aquifers or single-strata unconfined aquifers. In other cas
es, the boundary condition equations associated with resistant barrier
s can be nonlinear and a new technique for iterative solution is emplo
yed. Implementation of these techniques in a computer program is teste
d and it is demonstrated by modeling various configurations of flow fu
nneled into a gap between two barriers.