Zone 7 Water Agency and City of Pleasanton Open Arroyo Mocho Trail Riparian Overlook and Steelhead Habitat Reach at Bernal Avenue

Watershed engineers with the Zone 7 Water Agency and trails planners from the City of Pleasanton Community Services Department dedicated a 1,800-linear-foot naturalized stream channel reach, a stone-and-timber riparian overlook plaza, and a repaved multi-use trail segment on Sunday afternoon along the Arroyo Mocho Trail at the Bernal Avenue and West Las Positas Boulevard crossing in central Pleasanton. Originating in the Cedar Mountain hills southeast of Livermore and flowing across the Tri-Valley to the Arroyo de la Laguna, the Arroyo Mocho serves both as a vital groundwater-recharge and flood-control channel and as Pleasanton's busiest east-west bicycle commuter spine.

Within the low-flow channel bed, fluvial geomorphologists replaced eroded trapezoidal dirt banks with stepped boulder-weir riffles, deep gravel percolation basins, and biotechnical willow-wattling root wads. The natural grade-control structures slow winter storm velocities during atmospheric rivers, increase percolation into the Livermore-Amador Valley groundwater basin by an estimated 420 acre-feet annually, and shade cool-water pools for native fish and western pond turtles.

Along the northern top-of-bank trail, contractors widened 2,400 feet of the Arroyo Mocho Trail to twelve feet of smooth asphalt and built a 1,600-square-foot semicircular Sonoma stone overlook deck at the Bernal Avenue bridge. A solar-powered ultrasonic stream-gauge kiosk displays real-time creek flow and aquifer recharge metrics for passing students and cyclists.

The $615,000 flood-channel and trail enhancement was funded jointly by the Zone 7 Water Agency Flood Protection Fund and the City of Pleasanton Trails Master Plan reserve. Interactive Tri-Valley trail maps and groundwater reports are available on the Zone 7 Water Agency Official Website.