Some unique way to define the Civic Area as a cohesive space. As is, it feels like a bunch of loosely connected grassy areas. I never really know --intuitively-- when I'm entering/exiting the Civic Area proper. One thing I think has to be imposed upon the CA is some formalism, to balance the organic, overlapping strata of today's CA.
One idea would require some neat engineering like raising the entire area (or a subset of the CA) onto an equal plain 2 feet above the surrounding grade, like a civic podium. Anyone entering the CA would literally have to step up, acknowledging on an intuitive level that "this is a cohesive area." It could easily be made accessible for those in wheelchairs, etc. It could also be done in sections, and have an elegant sandstone wall-like feature at the edges gently sloping to the surrounding areas (so that it appears less obstructive than a perpendicular wall).
Another way might be to divert some water from Boulder Creek upstream into two small water features that form a border --almost like 2 arms hugging-- the CA. They would be rejoined to the Creek exactly at the eastern edge of the CA. It would have to be simple but effective. And highly formalized along the edge. Maybe hire a noteworthy landscape architect to create an attractive, modern edge that requires to more than a simple, stylized bridge to gain access to the CA (it would be so tiny though, you could hardly call it a bridge). Or for the edges that don't intersect a path/sidewalk, a small simple step-over would get you in or out.