SMUD power content label: [
www.smud.org]
TL;DR...
Total SMUD small and large hydro in 2013 (last year of final records; 2014 is estimated): 17%
Total SMUD renewables (eligible renewables + large hydro) in 2013: 39%
State average total renewables in 2013: 27%
Muni (SF) probably does better because it's supposedly powered from the hydro plants along the Hetch Hetchy aqueduct.
Rest of the state does worse and would be truly horrible if not for Diablo Canyon throwing a bit of nuke into the mix.
Interesting subject but the railroad connection is tenuous.