LAKE TAHOE, Nev./Calif. – The Tahoe Regional Planning Agency (TRPA) is reminding property owners and contractors that the annual grading and digging season for permitted projects will close Thursday, October 15, 2026. All construction sites must be winterized from October 15 to May 1 each year to protect Lake Tahoe’s famed water clarity.

The long-standing requirement helps prevent sediment from washing into stormwater systems and the lake. Disturbing or compacting soil during Tahoe’s wettest time of year can harm lake clarity and increase algal growth. TRPA’s winterization requirements are available on trpa.gov/applications-forms/winterization-guidelines.

The agency may permit grading season exceptions under special circumstances such as public health, safety, or water quality emergencies. The application for an exception is available at trpa.gov/inspections-and-securities. Applications can be submitted beginning October 12, 2026.

Some digging activities are considered exempt and do not require TRPA approval. The exemption applies year-round, but to remain exempt, these activities must adhere to water quality standards and continue only during dry conditions. When a site is wet or covered with snow, work must stop and the site must be stabilized following the winterization guidelines at the link above. A list of exempt projects is under “How do I know if I need a permit?” at trpa.gov/frequently-asked-questions.

The grading and digging season for permitted projects at Lake Tahoe will open again May 1, 2027.