North is at the top. On the left edge is the Cargill Salt Pond A3W (see Sunnvyale Salt Ponds - Part 1). The Sunnyvale Water Pollution and Control Plant (WPCP) is at the bottom and gives public access to the Sunnvyale ponds (which Joe Morlan calls the Sunnyvale sewer ponds). I don't know any formal name for the two "sewer" ponds. Some folks call the big one the "large pond" or the "west pond" so I guess the other must be the small pond or the east pond. Along the top is Guadalupe Slough which is the estuary for Calabazas Creek and San Tomas Aquinas Creek, but not for the Guadalupe River which empties into Alviso Slough instead. Across Guadalupe Slough are the Alviso salt ponds that lie between Guadalupe and Alviso sloughs and lead out to the Knapp property or Knapp tract. Cargill Salt Pond A4 is to the right. Both Sunnyvale ponds are free of access by foot or bicycle. A scope is probably essential. If you want a short trip during the shorebird season then just go out the middle levee system and take one side going out and the other coming back. Guadalupe Slough is tidal and the shorebirds often forage out there on a rising or falling tide and are not found in the ponds. During winter, a loop of one or both ponds is nice.
The plumbing in this area is quite strange and I don't claim to have figured it out. If you walk out to the Sunnyvale ponds from the public shore access point off Borregas there is a drainage channel on your right. As you reach the first corner you will see on your left three channels. The first channel, the one closest to downtown Sunnyvale, is a freshwater channel that carries storm drain and industrial waste water from Moffett Field and moves it through the pumping station there, I believe, into the drainage channel on the other side of the levee. From there this channel heads northeast towards Guadalupe Slough and is referred to on the Mountain View topo as the "Moffett Channel." It is no accident that this is where we find Green Herons and Common Moorhens. The next channel on your left, moving out to the bay, is the transport channel for Cargill salt water moving from A3W to A4. Finally, the third channel is part of the Sunnyvale WPCP treatment - dual levees with a channel between appear to be the standard for the WPCP. It appears that some of the WPCP delectables come up inside one of these channels not far from the first corner - at least Bonaparte's and Mew gulls are often doing their little dance on the surface of the water here, looking for goodies. [WGB, 2 Jan 97]