Mountain View commission backs expansion and pile‑pier barrier for Sailing Lake habitat island

Raymond Walt, watershed manager for the City of Mountain View, presented the Sailing Lake Habitat Island Alternative Analysis and recommended restoring the island to a larger historic footprint while installing a pier‑style perimeter barrier to reduce erosion and discourage human disturbance.

Walt told the Parks & Recreation Commission that the island’s footprint has declined from about 0.18 acres (1991) to roughly 0.11 acres (2023). He said staff documented nesting use—on the order of hundreds of nesting birds per breeding season—and concluded the island is ecologically important for shorebirds. Staff evaluated a do‑nothing option, a limited restoration (Alternative 1) and a larger restoration (Alternative 2). Based on scoring across engineering, environmental benefit, regulatory constraints, and recreational impact, staff recommended Alternative 2 and barrier Alternative C (a driven‑pile pier system wrapped with a chain or perimeter element) as the preferred package to restore form, function and long‑term reliability.

Walt explained the pier system (Alternative C) differs from floating buoy or cable systems because driven piles anchor into the lakebed and are less likely to sink or lose effectiveness as organic material collects. He said the barrier spacing is still under design but preliminary separation of 50–150 feet between posts is under consideration and the visible barrier height would be modest to avoid creating predator perches; staff expects to schedule construction during non‑nesting months to reduce disturbance.

Public commenters including Bruce England and Celia Pammer (Green Spaces Mountain View) and representatives of the Santa Clara Valley Bird Alliance supported the recommendation, emphasizing erosion control and the island’s value for skimmers, terns and other nesting birds. Commissioners pressed staff on predator‑perch risk, barrier visibility for boaters and maintenance implications; staff said rope/material choices and final heights will be refined in design.

Commissioner (mover) read the motion recommending approval of completion of environmental clearance, permitting and plans for the Sailing Lake Habitat Island as part of Shoreline Park Water Control Structures Improvement Project 2344, using restoration Alternative 2 (expand island toward historic size and repair eroded slopes) and barrier improvement Alternative C (drilled wooden piles). The motion was seconded and approved in a roll‑call vote (Commissioners Bryant, Filios, Summer, Vice Chair Michener and Chair Davis voted yes).

Next steps: staff will complete environmental clearance and permit documents, return to City Council as needed depending on required environmental documentation, and later seek construction authorization and funding to implement the restoration and barrier improvements.