Restore 25% of Disturbed SEZ
This indicator measures the restoration of stream environment zones (SEZ) that have been disturbed or developed. Prior to the establishment of TRPA regulations that limit development in SEZ, these areas were developed and degraded through development and harmful activities like grazing. SEZ plays a variety of critical roles including natural water filtration, storage, and conveyance of surface runoff. Naturally functioning SEZ also provides open space, flood flow capacity, riparian vegetation, fish and wildlife habitat, and buffer urban uses in developed areas. Through the Environmental Improvement Program (EIP), numerous SEZ restoration projects have been completed or are planned. SEZ restoration is tracked through the EIP program, and SEZ condition is monitored by EIP partners and TRPA.
Status
Cumulative SEZ restoration in the Lake Tahoe Region between 1980 and 2019 as a proportion of SEZ restoration target achieved.
Evaluation Map
Stream environment zones in the Tahoe Region and their rating. "A" rating is excellent condition, "B" is good condition, "C" is degraded condition, and "D" is very degraded condition.
2019 Evaluation
- Status
- Somewhat Worse Than Target
- Trend
- Moderate Improvement
- Confidence
- Moderate
Applicable Standard
SC12: Restore 25 percent of the SEZ lands that have been identified as disturbed, developed, or subdivided.
Key Points
- To date, restoration programs have achieved 96% of the threshold's goal: 1,057 acres of the 1,100-acre target for disturbed SEZ have been restored.
- As the Tahoe Region approaches this historic milestone, work is underway to establish new goals for SEZ restoration.
- The foundation for any new goals will be the comprehensive stream environment zone (SEZ) baseline condition assessment completed in 2020 by TRPA and EIP partners. The SEZ condition assessment is a benchmark for measuring the benefit of identified ongoing and future restoration projects.
About the Threshold
- This indicator measures the protection, restoration, and enhancement of stream environment zones (SEZ). SEZs play a variety of critical roles including natural water filtration, storage, and conveyance of surface runoff. Encroachment on these areas reduces their potential to filter sediment and nutrients and the amount of surface runoff they can effectively treat. Naturally functioning SEZs also provide open space, flood flow capacity, riparian vegetation, fish and wildlife habitat, and buffer urban uses in developed areas. SEZ protection and restoration can also contribute to the achievement of other environmental threshold standards, including water quality, wildlife, fisheries, vegetation preservation, recreation, and scenic resources. Even seemingly unrelated threshold standards such as air quality and noise are affected by SEZs. For instance, aspen stands in SEZs next to roadways have been shown to moderate roadway noise and help block particulates from spreading to adjacent areas.
- Disturbance and degradation of SEZs in the Tahoe Region began in the 1800s through logging, grazing, stream, and river channelization, development, damming, fire suppression, and other activities, with environmental consequences that are still evident today. Higher temperatures and altered precipitation regimes forecasted as a result of climate change further threaten to alter the dynamics of SEZs in the basin.
Delivering and Measuring Success
EIP Indicators
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Acres of SEZ Restored or Enhanced
This EIP performance measure tracks the amount of SEZ that is restored or enhanced by EIP partners to regain natural or historic function and values.
Example EIP Projects
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Upper Truckee River Watershed/Ecosystem Restoration: Reach 5 & 6 Planning & Reach 5 Construction
This project, completed in 2017, restored 123 acres of SEZ along a portion of the Upper Truckee River.
Rationale Details
- 1057 acres of disturbed SEZ have been restored since 1982, which is 96% of the goal of 1100 acres. Therefore, the current status is "somewhat worse than target".
- There has been a steady increase in the amount of SEZ restoration through the years. Therefore, the current trend is "moderate improvement".
Confidence Details
- Moderate. The EIP program tracks all SEZ restoration projects that have been completed over the years. However, the actual SEZ condition has not been tracked in the past. Therefore, confidence in the current status is moderate.
- Moderate. The EIP program tracks all SEZ restoration projects that have been completed over the years. However, the actual SEZ condition has not been tracked in the past. Therefore, confidence in the current trend is moderate.
- Moderate.
Additional Figures and Resources
No photos available.
No documents available.