This indicator measures the amount of excellent stream habitat in streams of the Tahoe Basin. Stream habitat includes features such as gravel, boulders, large wood, pools, riffles, and riparian vegetation that provide habitat for a wide variety of organisms. Streams are critical to the Lake Tahoe Basin’s water cycle by feeding freshwater to lakes and ponds, recharging groundwater, providing habitat for a wide variety of aquatic and terrestrial organisms and corridors for fish and wildlife migration. Past practices such as gravel mining, logging, and develpoment along stream corridors negatively impacted fish habitat. Regional programs such as removing impassable culverts and stream habitat restoration projects aim to improve stream habitat. Physical stream habitat (large woody debris, boulders, etc.) and benthic macroinvertebrates (mayflies, stoneflies, etc.) are used to monitor the health of Tahoe's streams.

Status

Average California Stream Condition Index (CSCI) scores of all "trend" sites for each time period. 

TRPA

Applicable Standard

Maintain the 75 miles of excellent stream habitat as indicated by the Stream Habitat Quality Overlay map, amended May 1997, based upon the re-rated stream scores set forth in Appendix C-1 of the 1996 Evaluation.

Key Points

  • There continues to be more stream miles in excellent condition than the threshold standard.
  • There is a slight increase in the amount of stream miles in excellent condition due to several large restoration projects and better stream flows during the 2016-2019 period compared to the drought years of 2012-2015.
  • Because the threshold standard set in 1982 called for maintaining the amount of streams in excellent condition, it is highly likely the Basin is meeting its threshold goal due to the large amount of stream restoration projects that have been completed in the past 30 years.

Delivering and Measuring Success

EIP Indicators

Example EIP Projects

Monitoring Programs