Lake Tahoe environmental report shows promising results

Several environmental gains over the last five years have been made at the Lake Tahoe Basin, according to the Tahoe Regional Planning Agency’s “Threshold Evaluation Report” released Wednesday, which highlights water quality as a continued area of concern.

The comprehensive report offers a snapshot of the health of the ecosystem in the Tahoe Basin by documenting the status and trends of more than 100 environmental standards ranging from air and water quality to fish and wildlife. The biggest improvements were documented in air and water quality, and scenic resources.

This evaluation is the fifth report published since the adoption of the Regional Plan in 1987 and was reviewed by an independent panel of scientific experts. The Tahoe Science Consortium coordinated the peer review and the scientists found the report to be technically sound and an improvement over previous evaluations, according to the report.

“This is a proud day for TRPA,” said Joanne S. Marchetta, Executive Director, “Not only because the majority of environmental standards measured at Lake Tahoe are moving in a positive direction, but because we’ve raised the bar on the scientific rigor of our work here at the Agency.”

Other public officials weighed in on the results the technical report.

“Lake Tahoe doesn’t belong only to Nevada or to California — it belongs to every citizen of the United States,” said Senator Harry Reid. “Those of us who love this lake, like I do, have a duty to our fellow citizens to protect it. It’s important we measure how the environment is responding to our policy actions on the ground and this report shows our collective actions are making a positive, meaningful difference.”

Partners in the Environmental Improvement Program, launched in the late 1990s, have invested $1.5 billion in ecosystem restoration in the Tahoe Basin with water quality investments being one of the highest priorities. The rate of Lake Tahoe annual clarity decline has slowed over the last decade. The report states the winter clarity threshold indicator met the interim target of 78.7 feet (2011 measured 84.9 feet) and is trending toward attainment of 109.5 feet. However, summer clarity and shoreline or so-called near shore conditions are highlighted as major areas of concern.

“Lake Tahoe is truly the Jewel of the Sierra and I’m very encouraged to see TRPA’s progress toward meeting its environmental quality standards,” said US Sen. Dianne Feinstein, D-Calif. “This report underscores why we have invested in ecosystem restoration for the last 15 years and why we need to reaffirm our commitment to restoring the Tahoe Basin.”

The threshold report highlights water quality (particularly along the lake’s shoreline), soil conservation, and noise as areas of concern for the Tahoe Basin. Another finding includes the need for improved monitoring and simplification of environmental threshold standards.
“Basing policy decisions on the best available science is fundamental to continuing our important restoration work at Lake Tahoe,” Marchetta said “and our Governing Board will have the benefit of this vast assemblage of data to make informed decisions later this year on the Regional Plan Update.”

Report Highlights:
The 2011 Threshold Evaluation provides a snapshot of the overall environmental health of the Tahoe Basin and is the fifth report published since the adoption of the Regional Plan in 1987.

— An independent panel of scientists coordinated by the Tahoe Science Consortium reviewed the 2011 Report and found it to be technically sound.
— TRPA tracks 151 environmental standards and made a status determination on 92 of these standards. Of these, 63 percent were attained or implemented and 37 percent have not been attained.
— The peer review stated the 2011Threshold Evaluation represents a significant improvement over previously published reports. The panel commended TRPA for using a more transparent process to determine threshold attainment status at the standard level.
— Overall, the Report found the Regional Plan, through the partnerships of many federal, state, local, and private organizations, has made progress on improving environmental quality.
— Water Quality: the rate of Lake Tahoe annual clarity decline has slowed over the last decade. The winter clarity threshold indicator met the interim target of 78.7 feet (2011 measured 84.9 feet) and is trending toward attainment of 109.5 feet. Trends in stream water quality indicated that conditions have not declined. However, summer clarity and nearshore conditions are highlighted as major areas of concern.
— Air Quality: the Tahoe Basin made air quality gains over the last five years. The majority of air quality indicators in the Lake Tahoe Basin were at or better than attainment with adopted standards. The report shows that indicators for carbon monoxide and vehicle-miles-traveled moved from non-attainment into attainment.
Federal and state tailpipe and industrial emission standards have likely contributed to this achievement along with local projects which delivered walkable, transit-friendly improvements such as the Heavenly Gondola in South Lake Tahoe.
— Soil Conservation: A preliminary analysis of impervious cover showed that eight of nine indicators related to impervious land coverage were in attainment with threshold targets, however, sensitive wetlands continue to be “over-covered” which negatively affects water quality and other resources. Quality control on soils data is expected to be complete this fall. Stream zone restoration efforts implemented by TRPA partner agencies are making progress in achieving restoration goals with more needing to be done.
— Scenic Resources: the Tahoe Basin made gains in scenic quality over the last five years. Overall, compliance with scenic quality standards is at 93 percent with an improving trend in scenic quality for the built environment. Developed areas along roadways and Lake Tahoe’s shoreline continue to be the locations where scenic improvements are needed.
— Vegetation: the Regional Plan and partner agencies have successfully protected sensitive plant species, keeping those standards in attainment. However, one location that supports an uncommon plant community fell short of attainment because of beaver populations (Osgood Swamp, South Lake Tahoe). Aquatic invasive species and noxious weeds were also identified as threats to uncommon plant communities. Progress is being made on fuels reduction and forest ecosystem restoration.
— Recreation: both threshold standards have been implemented and are in attainment. TRPA partners have made substantial progress in upgrading recreational facilities through the Environmental Improvement Program.
— Fisheries: TRPA and partner agencies have implemented robust aquatic invasive species programs, however, aquatic invasive species are a major area of concern and threaten fisheries and other resources.
— Wildlife: indicators for special interest wildlife species show stable or improving conditions. TRPA’s development regulations have protected riparian wildlife habitats and partner agencies are making progress restoring these valuable habitats.
—Noise: TRPA and the peer review panel recommended that noise standards and approaches be re-evaluated. The majority of standards were determined to be out of attainment as a result of a ‘no exceedance’ interpretation of the standard and TRPA has little enforcement authority to address most noise issues.

TRPA and the peer-review panel highlighted data gaps and the need to continue ongoing work to update Basin-wide monitoring programs. The scientific panel made recommendations to include additional analysis to improve future reports.

See the report and the draft Regional Plan Update and corresponding documents at www.trpa.org.

— Writer Kristi Boosman is the public information officer for the Tahoe Regional Planning Agency. She can be reached at kboosman@trpa.org or (775) 589-5230. Jeff Cowen is TRPA's Community Liaison. He can be reached at jCowen@trpa.org (775) 589-5230.