This indicator measures the amount of marginal 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.


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

Applicable Standard

Maintain the 38 miles of marginal 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 are more stream miles in marginal condition than the goal for the threshold standard. 
  • There is a slight decrease in the amount of stream miles in marginal condition due to several large restoration projects and better stream flows during the 2016-2019 period compared to the drought years of 2012-2015.

Delivering and Measuring Success

EIP Indicators

Example EIP Projects

Monitoring Programs