Muskrat

@ Karen ,this link provides info on the status of beavers.
http://wiki.answers.com/Q/Are_beavers_en....
Though in this spotting the animal was way smaller than an average beaver and had a tail that was on the edge.

Thanks. I started wanting to know the world around me when I was 3 or so. My parents indulged my desire with hordes of field guides and lots of outdoor trips. Some of those images are ingrained in my memory to the point that when I see something, I simply say the name, even if I've never encountered it, and don't remember where I saw the picture. Math was never my strong suit, so I went into art instead of science. Noah is the perfect place for me.

Are beavers not protected in California? My guess would be a muskrat too, unless you have seen a beaver and this rivaled it's size

@ karen ,In the feb 23rd meeting the Mr Cook of the City of Walnut Creek talked about findingone Nutria in the lake.
"Mr. Cook also talked about Joey Smith who has been back out and has caught five beavers and a nutria"
Other than that there have not been any spottings recently.
i am more inclined to go with muskrat because of the size and i did not see any brown teeth either.
The round tailed muskrat is found in Florida only.
Thanks again for the Id .
your knowledge is amazing!

Oh... Wiki notes that california eradicated coypu/nutria and you are at the southern most range for muskrat. I suppose if you did find a nutria, you should call CFWD

What approx size was this? Nutria look like Muskrat, but are quite a bit larger... like a small beaver(living in the NW I've seen a beaver boar that must have weighed in at well over 50 pounds and he was sitting sedately in a drainage ditch at the side of a road in a busy part of Salem Or). Nutria or Coypu have been introduced in parts of N America apparently. So you have a chance of it being either. Nutria have much shorter denser fur, however.
http://en.wikipedia.org/wiki/Coypu
http://en.wikipedia.org/wiki/Muskrat

http://en.wikipedia.org/wiki/File:Myocas...
this is a swimming nutria,

I don't beleive it is a beaver, for the tail is diffrent. A beavers tail looks like http://blogs.riverfronttimes.com/gutchec...
a muskrat tail looks like http://talk2theanimals.net/wp-content/up...

Thanks for your valuable feedback Karen , Then what is a nutria?

Tail tells all! You wouldn't mistake a beaver because of the very obvious flat tail

I will try and upload a picture of its face. i am more inclined to think that this is a musk rat. Had lot of whiskers. Want to rule out beaver.