At about 2:30 Sept 3, 2012, I found a waterthrush with a white unmarked throat, white underparts excepting the buffy salmon wash on the lower flanks, and a broad supercilium that flared a tad at the posterior end. I could not seen a contrasting buffy color on the lores. It wagged it entire rear end in a swishing side-to-side motion. The call note was tonally flat compared to the call note of Northern Waterthrush.
I observed it for about 5 minutes before it moved into the thick shoreline tangles. Over the next 3 hours, I had just two more encounters. In both instances it was more a case of hearing only as my sightings were dark silhouettes or flight only views.
We had better luck after Susan and Bob Steele arrived at 5:30. Viewing conditions were challenging, but Susan was able to confirm my details. It called dozens of times. We all agree that the call note matched the recording of a Louisiana Waterthrush. We were able to keep tabs on it until 7:15PM.
The Par 3 course is a public facility - for golf - not birding.
Try checking in with the staff person in the office by the parking lot. If it is closed, you are on your own. Golfers always have priority. They have been very generous and accommodating in the past, but they have never experienced a rare bird chase. Please be on your best behavior.
The Par 3 golf course in the SE corner of Cal City Central Park (near intersection of Cal City Blvd and 20 Mule Team Rd.) The waterthrush favored the lake shoreline between the 18th tee and the 17th tee, but it was also seen and heard along the entire shoreline, East from the parking lot to the 17th tee.
From the parking lot, walk east following the shoreline. The waterline is all but impossible to view, so listen closely for its call note. Best viewing would be from a canoe!
Garden Grove, CA