In seeking more information on the potential for more drought following the current floods, I ran across some additional drought information in this study:
Klamath/San Joaquin/Sacramento Hydroclimatic Reconstructions from Tree Rings, February 7, 2014, David M. Meko, Connie A. Woodhouse, and Ramzi Touchan
The reconstructed flows in the Klamath, Sacramento, and San Joaquin basins allow an assessment of the instrumental period of record, in terms of drought duration and severity, in a long-term context, The longest run of below median flow years extends to 21 consecutive years in the Klamath River reconstruction, 10 years in the Sacramento and 13 years in the San Joaquin Two intervals of 10 years are indicated in the Sacramento: late 1200s and in the 1920s-1930s. In the San Joaquin, the 13-yr run occurs in the late 1400s. The 21-yr run in the Klamath occurs in the mid- to late 1600s. Numerous periods of low flows of four years and more are evident in all three series.
Reconstructions for the Sacramento and San Joaquin flag 1580 an exceptionally dry single year – far drier than any experienced in the instrumental period. On the Sacramento, the reconstructed flow for 1580 is only 45% of that of the reconstructed flow in 1924, the second driest year of the reconstruction. The relative severity of low flow in 1580 is almost as great on the San Joaquin, where flow in 1580 is reconstructed at 54% of the flow in 1924. The single-year intensity of tree-ring reconstructed drought in 1580 has been noted previously (Meko et al. 2001). Our results suggest that the drought beginning in the 1570s and including 1580 was of shorter duration in the San Joaquin Basin than in the Sacramento Basin. The 1470s are also a key period of low flow in both basins. At decadal and longer time scales, pre-20th century low flow extremes are dominated by periods in the mid- to late-1100s in the Sacramento basin, while the second half of the 15th century appears to have been more severe in the San Joaquin basin (however, prolonged drought is evident for both of these periods in both basins).
While you are here, look at the period between 1100 and 1200 and note the extensive number of closely spaced drought periods from about 1125 to 1165 This is the period when the Arizona Cliff Dwellers abandoned their historic homes and went in search of a more agreeable climate, a place with water and weather that would allow them to plant and harvest grains, corn, and squash.