Measuring What Matters: Threshold and Monitoring Update Strategic Initiative

One of TRPA’s strategic initiatives focuses on how information is collected, analyzed, and applied to support better decisions that accelerate environmental improvement. The initiative’s scope includes review of the threshold standards that establish TRPA’s goals and updating the suite of performance measures the agency uses to assess effectiveness of all components of the Regional Plan.

In 2022, the Environmental Improvement Program coordinating committee identified a subset of the 10 threshold standard categories upon which to focus: Air Quality, Fisheries, Soil Conservation, Vegetation Preservation, Water Quality, and Wildlife. They created an outline for threshold standard development, and identified 22 goals to guide the update.

For additional information or to be added to the initiative mailing list, please email Dan Segan,

Air Quality
Standards Report

Forest Health
Standards Report

VMT (Vehicle Miles Travelled)
2021 Threshold Update
Original VMT Threshold Standard Background

(Other thresholds to be added as discussed)

Threshold Update Initiative Stakeholders Working Group Meetings

The Threshold Update Initiative Stakeholders Working Group is comprised of Advisory Planning Commission members charged with providing feedback on the overall direction for the initiative, as well as providing recommendations on partner and stakeholder engagement. The group was appointed by the TRPA Governing Board in March of 2022. Click here to view a list of members.

August 10, 2022:
Full Summary
Meeting Materials

July 13, 2022:
Full Summary
Meeting Materials

Tahoe Science Advisory Council

The Tahoe Science Advisory Council was established in 2015 by a memorandum of understanding (MOU) between the State of California and Nevada. The Council is an independent group of scientists who work collaboratively to advise policy makers to promote, enhance, and maintain the ecological integrity of the Lake Tahoe and its watershed. Council work related to the threshold standard update can be found below, and additional information on the council can be found on their website:

2020 – Implementation of a System Structuring Approach for Water Quality Threshold Standards
2018 – Guidance on Technical Clean Up of Existing Threshold Standard
2017 – Natural Resource Evaluation Systems Assessment – Heyvaert et al.
2017 – Threshold Assessment Memo
2017 – Comments on Threshold Assessment Methodology