Sacramento is not really in the San Joaquin Valley but let me give you a few places to contact.
There are 2 Catholic dioceses in the SJV and they cover the areas you are probably hearing about, particularly the farm towns hit by the drought. I'd suggest going through the diocese Catholic Charities offices.
If you prefer to support St Vincent de Paul or some other type of parish food pantry just ask here and I'll try to locate a couple.
For the region from about Merced to Bakersfield, Catholic Charities in Fresno has several St Vincent de Paul centers as well as other food bank programs:
Roman Catholic Diocese of Fresno
For the area around Stockton and Modesto, try Catholic Charities in Stockton
Catholic Charities Diocese of Stockton