Truckee River at Vista — Page Note

Current Status: Streamflow is significantly diminished. At 312 ft³/s, discharge is 42% below the 5-year median and represents a marked decline across all comparison periods:

• Week-over-week: Down 17.7% from 379 ft³/s
• Month-over-month: Down 58.1% from 744 ft³/s
• Year-over-year: Down 46.3% from 581 ft³/s

Assessment: The steep month-over-month drop (more than half the prior month's flow) indicates accelerating depletion, likely driven by late-spring/early-summer irrigation demands and reduced snowmelt from the Sierra Nevada high country. The year-over-year comparison suggests conditions this summer are notably drier than 2025. Current flows are approaching or at seasonal low-water conditions typical of August–September.

Context: Truckee River discharge feeds both irrigation districts and Lake Tahoe's outflow regulation. Sustained low flows at this magnitude may signal stress for downstream agricultural demand and constrain Tahoe's ability to maintain target elevations during the dry season.