This afternoon, my wife and I hiked the Sweetwater Riding and Hiking Trail that goes along the south shore of the reservoir. It really doesn't get very close to the reservoir (hence no gulls or small waterfowl in my list; they were too far away to ID even with my scope)), and traverses the grassy scrub through the Wildlife Preserve. Lots of singing meadowlarks.
But the highlight was a large flock of Canada Geese accompanied by three adult Snow Geese. These were all in a fenced off field about half a mile from the trailhead at Sweetwater Summit Park, by the first wooden horse bridge. When we returned, the Canadas all seemed to be there, but the Snow Geese had left.
Photos in this checklist: https://ebird.org/view/checklist/S52190259
Source: SanDiegoRegionBirding Latest Reports