Gunnels

The Gunnels, or Gunn Tunnels, are a pair of culverts forming the Barron Creek Bypass Structure. They are walkable during the dry season and have for years been a popular location for Gunn students to "hang out". They are relatively well-known in the community surrounding Palo Alto, so students from other schools often visit as well. Graffiti covers most of the tunnel walls and large parts of the floors. As of Autumn 2024, there is still a soiled sofa in the tunnel. The Gunnels have a relatively low clearance and are only adequately ventilated near storm drains. Due to their construction and notoriety, the Gunnels are a wonderful venue for echo sax and other acoustic performances.

The Gunnnels (double dotted blue lines) run northwest from Barron Creek to Matadero Creek.

The tunnels are visible on OpenStreetMap but not Google Maps. You can view them at this link.

Barron Creek

Barron Creek begins in the foothills and runs north, meeting Gunn High School. From there it enters a debris basin (a basin to capture debris and prevent it from going downstream) and flows through a pipe under Los Robles Avenue, emerging at El Camino. It continues north until it empties, along with Adobe Creek into the Palo Alto Flood Basin. The flood basin is connected to the San Francisco Bay through a tide gate, which allows water to flow out, but not into the flood basin, ensuring its water levels remain low to prevent flooding.

To resolve the problem of frequent flooding during winter storms, the Gunnels (officially known as the Barron Creek Bypass) were constructed to divert water to Matadero Creek in times of heavy rain. The bypass (now called the Matadero Bypass) continues past Matadero Creek, meets the Stanford Channel (an artificial channel which brings water from Santa Rita Creek) at Matadero Avenue, and reunites with Matadero Creek at El Camino Real.

Entrances

The two main entrances to the Gunnel used by students are at the debris basin and at Matadero Creek, just beyond the Barron Park Donkeys. Both are sealed by a grate which has been pried open.

Other passable culverts

• The culvert that diverts Barron Creek under Gunn, beginning at Los Robles Avenue and ending at the debris basin is passable, but the ceiling is quite low
• The culvert that diverts Barron Creek under Los Robles Avenue, beginning at El Camino Real and ending at Laguna Avenue may be passable, and if it is, the ceiling is quite low.