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Multi-year droughts in Mediterranean , rainfall-dominated climates lead to shifts in climates :::: may :::: shift : the water balance, the fundamental precipitation-allocation rule ::: that :: is, ::: the partitioning :::: rule :: of precipitation : across runoff, evapotranspiration, and subsurface storage. Despite their fundamental implications, mechanisms sub-surface storage. Mechanisms causing these shifts as well as the extent to which they impact mixed rain-snow regimes remain largely unknown and are not well represented in 5 hydrologic models. Focusing on measurements from the headwaters of the California’s Feather River, we found that :::: also in these mixed rain-snow Mediterranean catchments basins a lower fraction of precipitation was allocated partitioned : to runoff during multi-year droughts compared to non-drought years. Comparing :::: This :::: shift :: in ::: the precipitation-runoff relationship :::: was larger :: in ::: the surface-runoff-dominated and subsurface-flow-dominated sub-basins, we observed different responses to drought: 39% lower runoff during drought in the surface-runoff-dominated versus 18% less runoff :::: than in the subsurface-flow-dominated 10 sub-basin. headwaters (-39% ::: vs. :::: -18% decline :: of runoff, respectively, ::: for : a representative precipitation amount). The predictive skill of the PRMS hydrologic model in these catchments basins decreased during droughts, with evapotranspiration (ET ) being the only water-balance component besides runoff for which this drop in performance :: the :::: drop :: in predictive ::: skill : during drought vs. non-drought years was statistically significant. In particular, the model underestimated the buffered response of response :::: time required :: by : ET to adjust :: to interannual climate variability, or which :: we define :: as : climate elasticity of ET . Differences 15 between simulated and data-driven estimates of ET were well correlated with accompanying data-driven estimates of changes in sub-surface storage (∆S, r = 0.78). This correlation points to shifts in precipitation-runoff relationship relationships being evidence of a hysteretic response of the water budget to climate elasticity of ET during and after multi-year droughts. This hysteresis is caused by carryover storage offsetting precipitation deficits deficit during the initial drought period, followed by vegetation mortality when storage is depleted and subsequent post-drought vegetation expansion. Our results point to a general 20 improvement in hydrologic predictions across drought and recovery cycles by including the climate elasticity of ET , and better accounting for actual subsurface water storage in not only soil, but deeper regolith that also stores root-accessible water