The present technology is directed to adjustable shunting systems for draining fluid from a first body region to a second body region, and can include a shunting element, an aperture in the shunting element, and an actuator for selectively controlling the flow of fluid through the aperture. The actuator can include a gating element moveable between a first position in which it does not substantially interfere with fluid flow through the aperture and a second position in which it at least partially blocks fluid flow through the aperture, and a shape memory actuation element configured to move the gating element from the first position to and/or toward the second position when actuated. The system can further include a friction element configured to frictionally engage the gating element to releasably retain the gating element at and/or proximate the second position following actuation of the shape memory actuation element.