Functional Assessment		Potential Future Drivers
Variable / Sub-Variable	Existing Condition	Increasing Municipal Water Use	Urbanization	Warm & Wet Climate Future	In-Between Climate Future	Hot and Dry Climate Future	New TMDs	Increased Reservoir Capacity	Wildfire
Streamflows
Base Flow: Dry Year	A			Onset and peak snowmelt shift earlier in season, exacerbating severity and duration of late season low flow spells	Onset and peak snowmelt shift earlier in season, coupled with increasing air temperatures, exacerbating severity and duration of late season low flow spells	Onset and peak snowmelt shift earlier in season, coupled with increasing air temperatures, exacerbating severity and duration of late season low flow spells		Reservoir augmentation of late summer baseflows may somewhat mitigate climate-induced reductions.
Base Flow: Median YearIncreased TMDs drive additional declines in total available flow volume in typical years, affecting base flows.	A			Low flow spells increase in severity and duration	Low flow spells increase in severity and duration	Low flow spells increase in severity and duration	Increased TMDs drive additional declines in total available flow volume in typical years, affecting base flows.	Reservoir augmentation of late summer baseflows may somewhat mitigate climate-induced reductions.
High Peakflow FrequencyIncreased TMD diversions during high flow season further reduce the return frequency of high peak flows.	D			Wetter and warmer climate future slightly increases peak flow magnitudes and variability		Streamflow losses to warming temperatures outpace potential precipitation gaines, reducing magnitude and frequency of flood flows	Increased TMD diversions during high flow season further reduce the return frequency of high peak flows.	Upstream reservoir fills diminish peak flood flow magnitudes and frequencies
Peak Flow: Dry YearIncreased TMD diversions further reduce peak flow magnitudes, durations, or frequency in dry years.	C			Wetter and warmer climate future slightly increases peak flow magnitudes and variability; increased peak flows may be accompaied by shorter duration of high flows.	Warmer climate future slightly increases peak flow magnitudes and variability; increased peak flows may be accompaied by shorter duration of high flows.	Streamflow losses from warming climate result in declines in magnitude and frequency of peak flows	Increased TMD diversions further reduce peak flow magnitudes, durations, or frequency in dry years.	Upstream reservoir fills diminish peak flood flow magnitudes and frequencies
Peak Flow: Median YearIncreased TMD diversions further reduce peak flow magnitudes, durations, or frequency in typical years.	B				Streamflow losses from warming climate result in declines in magnitude and frequency of peak flows	Streamflow losses from warming climate result in declines in magnitude and frequency of peak flows	Increased TMD diversions further reduce peak flow magnitudes, durations, or frequency in typical years.	Upstream reservoir fills diminish peak flood flow magnitudes and frequencies
Total Volume: Dry YearIncreased TMD diversions further reduce total annual flow volume in dry years.	C				Total streamflow declines due to warming temperatures (increased vegetation ET demand, lower soil moisture, longer growing/irrigation season) drive overall streamflow declines	Total streamflow declines due to warming temperatures (increased vegetation ET demand, lower soil moisture, longer growing/irrigation season) drive overall streamflow declines	Increased TMD diversions further reduce total annual flow volume in dry years.
Total Volume: Median YearIncreased TMD diversions further reduce total annual flow volume in typical years.	A				Total streamflow declines due to warming temperatures (increased vegetation ET demand, lower soil moisture, longer growing/irrigation season) drive overall streamflow declines	Total streamflow declines due to warming temperatures (increased vegetation ET demand, lower soil moisture, longer growing/irrigation season) drive overall streamflow declines	Increased TMD diversions further reduce total annual flow volume in typical years.	Total streamflow declines due to warming temperatures (increased vegetation ET demand, lower soil moisture, longer growing/irrigation season) drive overall streamflow declines
Streambed Sediment
Continuity and TransportFurther decreases to peak flows and total volumes decrease sediment transport capacity and loads from current levels.	A		Increased flashiness, physical channel impacts (bank cover, resistance, hydraulic geometries) alter sediment supply and transport regimes	Increased peak flows or frequency of effective discharges maintains channel's self-maintenance capabilities		Decreased total volumes and base flow magnitudes salter total annual sediment transport capacity	Further decreases to peak flows and total volumes decrease sediment transport capacity and loads from current levels.	Changes in streamflow regimes including declines in peak flows and total volumes due to reservoir operations further alters sediment transport regimes	Increased watershed responsiveness can drive increased peak floods and sediment delivery, impacting channel shaping processes like erosion/aggradation rates and seasonal sediment transport
Flushing FlowsIncreased TMDs diversion volumes further reduce peak flows (geomorphic flows) and total annual flow, decreasing the frequency and duration of flushing flows.	A					Changes in flow regimes drive decreased frequency of discharges at or above sediment mobilization thresholds	Increased TMDs diversion volumes further reduce peak flows (geomorphic flows) and total annual flow, decreasing the frequency and duration of flushing flows.	Changes in flow regimes drive decreased frequency of discharges at or above sediment mobilization thresholds
Water Quality
Metals	A
Nutrients	C		WWTP effluent load increases with population; dilution issues during lowest winter baseflows. Stormwater fluxes from increased impervious coverage carry larger nutrient loads to streams;
Temperature	D			Increasing air temperatures and decreasing summer/fall baseflows creates increasing temperature risks for aquatic life	Increasing air temperatures and decreasing summer/fall baseflows creates increasing temperature risks for aquatic life	Increasing air temperatures and decreasing summer/fall baseflows creates increasing temperature risks for aquatic life		Reservoir management frameworks that include summer/fall baseflow augmentation may somewhat offset temperature risks from warming air and lower late seasons flows
Riparian Areas
Floodplain physical condition	C		Ongoing urbanization tends to further reduce floodplain connectivity with rivers; reduces total floodplain area; and simplifies or degrades floodplain habitats
Riparian vegetation	C		Continued development further alters, degrades, removes, or fragments riparian forest buffers		Changes to magnitude and frequency of peak flows alters may drive riparian floodplain vegetation over time toward transition to mesic (drier upland) habitat types	Changes to magnitude and frequency of peak flows alters may drive riparian floodplain vegetation over time toward transition to mesic (drier upland) habitat types		Changes to magnitude and frequency of peak flows alters may drive riparian floodplain vegetation over time toward transition to mesic (drier upland) habitat types	Increased frequency and/or duration of seasonal drying and hot spells exposes riparian forests to greater catastrophic fire risk
River Form
Channel Structure and Dynamics	B
Aquatic Habitat
Habitat Structure	A
In-channel Hydrologic ConnectivityIncreased TMD diversions decrease total annual flow volumes, potentially decreasing in-channel connectivity during low flows.	A			Baseflow declines reduce stream network connectivity during late summer and fall, potential impacts to refuge seeking movements, migration, and spawning activity	Baseflow declines reduce stream network connectivity during late summer and fall, potential impacts to refuge seeking movements, migration, and spawning activity	Baseflow declines reduce stream network connectivity during late summer and fall, potential impacts to refuge seeking movements, migration, and spawning activity	Increased TMD diversions decrease total annual flow volumes, potentially decreasing in-channel connectivity during low flows.	Reservoir augmentation of late summer baseflows may somewhat mitigate climate-induced reductions.
Aquatic Life
Aquatic Insects				Low flow spells severity and duration still increase in summer/fall still under WW future, negatively impacting abundance.	Low flow spells severity and duration still increase in summer/fall still under WW future, negatively impacting abundance.	Low flow spells severity and duration greatly increase in summer/fall HD future, negatively impacting abundance.		Reservoir augmentation of late summer and early fall baseflows helps maintain habitat refugia and cooler water temperature	Streambed Sedimentation and water chemistry impacts degrade physical habitat and water quality
Fish	A	Increased municipal diversions places increasing pressure on instream flows, water quality (temperature, DO, nutrients, etc.), habitat connectivity	Riparian impacts and increased stormwater pollutant fluxes are likely to degrade physical and chemical fishery habitat	Declining late summer/early fall flows place increasing pressure on instream flows, water quality (temperature, DO, nutrients, etc.), habitat connectivity	Declining late summer/early fall flows and increasing air temperatures place increasing pressure on instream flows, water quality (temperature, DO, nutrients, etc.), habitat connectivity	Declining late summer/early fall flows and increasing air temperatures place increasing pressure on instream flows, water quality (temperature, DO, nutrients, etc.), habitat connectivity