This work shows how differential forms and boundary conditions can be conveniently expressedin an appropriately constructed orthogonal or near-orthogonal coordinate system. As a special
case, two coordinate systems are constructed that map a R3 rectangle to two irregularly shaped
open channels and perturbation methods are used to handle a Laplacian equation in different
magnitudes.
Additionally, other attempts at constructing such coordinate systems are presented along with
their challenges.