Within this dissertation, a number of advancements are made with regard to hydraulic flocculation. In the first chapter, two models are developed for hydraulic flocculation performance in terms of suspended solids removal as a function of key flocculator and raw water characteristics. The first model assumes that viscous forces govern the transport of two colliding particles with respect to one another, while the second model assumes that inertial forces are dominant. Both models were used to predict results of a laboratory-scale turbulent flocculation and sedimentation process, resulting in similar predictions. Although the inertial model performed slightly better, the viscous model was recommended for engineering practice since the two models are very similar, and the core of the viscous model, the product of mean velocity gradient (G) and mean hydraulic residence time (θ) Gθ, has been a cornerstone of flocculator design for most of the last century up until the present. The second chapter follows up on the first with a further exploration of the effect of sedimentation capture velocity on performance. The experiments of the prior chapter had considered only one capture velocity, 0.12 mm/s, so that sedimentation had a constant effect on performance. However, as expected, when looking at six capture velocities ranging from 0.1 to 0.6 mm/s, capture velocity had an important effect on the selectivity of particles that were removed, and therefore performance. These experimental results showed that the value of k, a constant that relates the collisions of primary particles, i.e., colloidal particles, to the conversion of nonsettleable particles to settleable sizes, decreases exponentially with increasing capture velocity. Physically, this was linked to the area under the small-size tail of the particle size distribution curve, which can be modeled with an exponential function. Thus, the area under this curve is itself an exponential function. Taken together, the first two chapters provide a model for flocculation performance that can inform design and operation decisions. The third chapter gives an algorithm for the design of vertically-baffled hydraulic flocculators, which has been lacking in engineering literature. First, this chapter explores the theoretical and practical constraints for effective hydraulic flocculator design. It then details the design algorithm that AguaClara Cornell has developed for vertically-baffled flocculators. The AguaClara design for vertically-baffled flocculators is more compact than conventional designs for horizontally-baffled hydraulic flocculators at low flow rates, extending the range of applicability of hydraulic flocculators for engineering practice. Hydraulic flocculators are more efficient and sustainable than their mechanical counterparts, but they have been largely neglected as an option in the United States in recent decades. The work of this dissertation, comprising the performance prediction equation and the algorithm, is intended to be a resource for engineering practitioners who are designing or operating baffled hydraulic flocculators.