The Tahoe Regional Planning Agency’s (TRPA) environmental threshold evaluation report, which monitors the regional plan’s environmental factors across 140 indicators, shows that in 2019 to 2023, 75% of the indicators trended positively. … One major question in this report was on the ever-elusive lake clarity. Winter clarity has improved, indicating that projects that stop stormwater runoff and sediment collection in the lake are likely working. But summer clarity has been trending down over the years, with no clear answer as to why.