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	D	Increasing municipal demand further increases flow stress during summer/fall baseflows		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
Base Flow: Median Year	C			Low flow spells increase in severity and duration	Low flow spells increase in severity and duration	Low flow spells increase in severity and duration
High Peakflow Frequency	F			Streamflow losses to warming climate are outpaced by any potential precipitation increases, decreasing peak flow magnitude and return frequency	Streamflow losses to warming climate decrease peak flow magnitude and return frequency	Streamflow losses to warming climate decrease peak flow magnitude and return frequency
Peak Flow: Dry Year	C				Flow losses from warming climate are outpaced by any potential precipitation increases	Streamflow losses from warming climate result in declines in magnitude and frequency of peak flows
Peak Flow: Median Year	B			Flow losses from warming climate are outpaced by any potential precipitation increases	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
Total Volume: Dry Year	C			Total streamflow declines due to warming temperatures (increased vegetation ET demand, lower soil moisture, longer growing/irrigation season) outpace potential gains from precipitation increases, causing 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	Total streamflow declines due to warming temperatures (increased vegetation ET demand, lower soil moisture, longer growing/irrigation season) drive overall streamflow declines
Total Volume: Median Year	A			Total streamflow declines due to warming temperatures (increased vegetation ET demand, lower soil moisture, longer growing/irrigation season) outpace potential gains from precipitation increases, causing 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	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 Transport	A	Decreased total volumes and base flow magnitudes decreases total annual sediment transport capacity			Decreased total volumes and base flow magnitudes decreases total annual sediment transport capacity	Decreased total volumes and base flow magnitudes salter total annual sediment transport capacity			Increased watershed responsiveness can drive increased peak floods and sediment delivery, impacting channel shaping processes like erosion/aggradation rates and seasonal sediment transport
Flushing Flows
Water Quality
Metals	A								Runoff from burned areas increases dissolved metals loads to streams
Nutrients	A		WWTP effluent load increases with population; dilution issues during lowest winter baseflows. Stormwater fluxes from increased impervious coverage carry larger nutrient loads to streams;						Runoff from burned areas increases nutrient loads to streams
Temperature				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
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	B		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			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		Additional urbanization alters channel or bank structure, sediment regimes, erosion rates, and substrate characteristics like embeddeness/winnowing in currently less-impacted locations						Increased sediment fluxes impact channel shaping processes including aggradation rates and seasonal sediment transport
Aquatic Habitat
Habitat Structure	B		Riparian impacts, channel simplification, and bank alteration/armoring degrade physical habitat characteristics						Increased sediment fluxes degrade inchannel habitat quality including spawning sites and macroinvertebrate habitat
In-channel Hydrologic Connectivity	B			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. Some structures or reaches become impassible causing complete disconnect.	Baseflow declines reduce stream network connectivity during late summer and fall, potential impacts to refuge seeking movements, migration, and spawning activity. Some structures or reaches become impassible causing complete disconnect.
Aquatic Life
Aquatic Insects	A		Continued increases to impervious area, increased stormwater volumes, and riparian losses/degradation impact community balance and sensitive species	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.			Streambed Sedimentation and water chemistry impacts degrade physical habitat and water quality
Fish	B		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			Increased sediment fluxes degrade inchannel habitat quality and water quality, including spawning sites and macroinvertebrate habitat