The hydrodynamics at two design discharges (85 and 15 exceedence on the flow duration curve) in the vicinity of the existing North Branch Dam are presented. A combination boat chute/fish passage is being designed for integration into the existing dam. The Dutch pool and orifice fishway has been selected for the fishway due to its relatively low flow requirement (on the order of 5 cfs for most operating heads), low velocities in the fishway, and relatively low turbulence in the fishway - all making it a reasonable option for passage of non-anadromous fish in a low-gradient waterway. The details of the hydrodynamics of this structure are being examined with a combination of a physical model study and through the performance Computational Fluid Dynamic (CFD) modeling. © 2009 ASCE.