PWA - Project Detail - Cooley Landing

Cooley Landing is located in East Palo Alto at the western end of the Dumbarton Bridge, within the Ravenswood Open Space Preserve. Once part of a continuous band of tidal wetland fringing the shoreline of South San Francisco Bay, the 115-acre site was diked for salt production in the early 1950's. PWA provided the hydrologic, geomorphic and engineering components of the preliminary restoration design and project performance monitoring for the Cooley Landing tidal wetlands. Since its completion in December 2000, the project has been recognized as a model for future salt pond restorations in South San Francisco Bay.

Developed cooperatively with key regulatory agencies, the Project Objectives were to:

The marshplain had fallen in elevation due to more than two feet of subsidence. In response to this and the above Project Objectives, the project team recommended efforts to encourage estuarine sedimentation to raise the site to elevations at which vegetation could colonize. Tidal inundation and sediment supply were enhanced by excavating two channels through the east levee and fringing outboard marsh. Channel development was encouraged by directing tidal flows into the remnant natural tidal channels; these provide a more complex and varied channel habitat. Alternatively, flows were blocked to the man-made channels (borrow ditches) along the interior perimeter of the site. To provide new marsh habitat and fill for construction, the bayside levee was lowered to high intertidal elevations. A third breach location will occur when a temporary sheetpile wall and culvert are removed.

Close monitoring of tides and site bathymetry for three years after breaching have documented that geomorphic and hydrologic conditions were successfully restored. PWA sized the inlet channels and breaches to balance habitat and cost objectives; this provided nearly full tidal exchange within the first year. Designed to re-establish rapidly without costly excavation, the tidal channel system has exceeded expectations. The design and monitoring results have been used to inform other San Francisco Bay restoration planning efforts.

<< Return to project summaries
Title		Cooley Landing Restoration from Salt Pond to Salt Marsh (PDF) 160k
Project Summary		PWA provided the hydrologic, geomorphic and engineering components of the preliminary restoration design and project performance monitoring for the Cooley Landing tidal wetlands.
Date		1987 - present
Location		East Palo Alto, CA
Client		S.S. Papadopulos & Associates, Geomatrix Engineers (for Aventis CropScience USA)

Project Detail		Cooley Landing is located in East Palo Alto at the western end of the Dumbarton Bridge, within the Ravenswood Open Space Preserve. Once part of a continuous band of tidal wetland fringing the shoreline of South San Francisco Bay, the 115-acre site was diked for salt production in the early 1950's. PWA provided the hydrologic, geomorphic and engineering components of the preliminary restoration design and project performance monitoring for the Cooley Landing tidal wetlands. Since its completion in December 2000, the project has been recognized as a model for future salt pond restorations in South San Francisco Bay. Developed cooperatively with key regulatory agencies, the Project Objectives were to: Accelerate marsh colonization Encourage the formation of a complex tidal channel system for the benefit of special status species Preserve existing public access Minimize disturbances to existing habitat and Minimize construction costs. The marshplain had fallen in elevation due to more than two feet of subsidence. In response to this and the above Project Objectives, the project team recommended efforts to encourage estuarine sedimentation to raise the site to elevations at which vegetation could colonize. Tidal inundation and sediment supply were enhanced by excavating two channels through the east levee and fringing outboard marsh. Channel development was encouraged by directing tidal flows into the remnant natural tidal channels; these provide a more complex and varied channel habitat. Alternatively, flows were blocked to the man-made channels (borrow ditches) along the interior perimeter of the site. To provide new marsh habitat and fill for construction, the bayside levee was lowered to high intertidal elevations. A third breach location will occur when a temporary sheetpile wall and culvert are removed. Close monitoring of tides and site bathymetry for three years after breaching have documented that geomorphic and hydrologic conditions were successfully restored. PWA sized the inlet channels and breaches to balance habitat and cost objectives; this provided nearly full tidal exchange within the first year. Designed to re-establish rapidly without costly excavation, the tidal channel system has exceeded expectations. The design and monitoring results have been used to inform other San Francisco Bay restoration planning efforts.