Not all sparkling water has sodium. I drink Talking Rain which has absolutely no fat, no sodium, no carbs... just water and carbonation and, if you choose, a bit of fruit essence. Love the stuff! I often mix about 1/4 cup fruit juice in a 16 oz bottle of it... especially good is Welch's grape! Yum!!
Talking Rain is made in Washington so not sure if they ship it down south to you in California.

It's a local favorite around here. But if you check around you should be able to find some brand which does not have sodium!