This indicator measures the amount of excellent, good, and marginal habitat in streams of the Tahoe Region. 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 Tahoe Region'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 fish and wildlife migration. Past practices such as gravel mining, logging, and development along stream corridors negatively impacted fish habitat. Regional programs such as removing impassable culverts and stream habitat restoration projects aim to improve stream habitat. The health of Tahoe's streams is assessed by evaluating physical stream habitat (large woody debris, boulders, etc.) and benthic macroinvertebrates (mayflies, stoneflies, etc).


Average California Stream Condition Index (CSCI) scores of all trend sites for each time period. Site scores are put into three different categories of excellent (CSCI >0.92), good (CSCI = 0.79-0.92), or marginal (CSCI <0.79). The California Stream Condition Index (CSCI) measures the biological health of streams by assessing the community of benthic macroinvertebrate in perennial streams.

Evaluation Map

Stream ratings as of 2020 for the Tahoe Basin. Stream ratings incorporate stream health indicators such as fish passage, in-stream habitat, macroinvertebrate diversity, among others. 

2019 Evaluation

At or Somewhat Better Than Target
Moderate Improvement
View Evaluation

Applicable Standard

F1-F3: As indicated by the Stream Habitat GIS data, amended May 1997, based upon the re-rated stream scores set forth in Appendix C-1, of the 1996 Evaluation Report, maintain: F1) 75 miles of excellent stream habitat, F2) 105 miles of good stream habitat, F3) 38 miles of marginal stream habitat.

Key Points

  • Over the last 30 years, stream restoration projects have been completed through the Environmental Improvement Program (EIP) that were identified in the 1982 Threshold Environmental Assessment such as removing fish passage barriers, improving in-stream physical habitat (large wood, pools, etc.), reducing bank erosion, increasing stream shading, and removing flow diversions.
  • These EIP projects have allowed the Tahoe Region to meet its goal for stream habitat for the first time in 2020, with recent projects such as the Upper Truckee River Reach 5 project and numerous projects on Blackwood Creek putting the Region over the top for meeting the goal.
  • Between 2016-2019 EIP partners restored 14,680 linear feet of streams and enhanced 24,140 linear feet of streams.
  • While the overall amount of stream habitat has met the goal set in 1982, there are still numerous stream segments identified for restoration that still need to be completed such as removing the fish passage barrier at the mouth of Meeks Creek and restoring several sections of the Upper Truckee River. These projects will help move the Region further into attainment for stream habitat.

Delivering and Measuring Success

EIP Indicators

Example EIP Projects

Monitoring Programs