Lake Tulloch is in a major drawdown year. Tri-Dam's 2026–27 schedule, issued by U.S. Bureau of Reclamation hydrologic engineer M. Pacheco, lowers the reservoir in weekly steps from 501–504 feet this week to 475–478 feet from December 30, 2026 through February 1, 2027. The extra drop is there "to permit required inspections and testing" in January 2027. Last winter the lake held between 498.6 and 501.6 feet from October 28, 2025 to March 23, 2026. That puts this January's floor roughly 23 to 24 feet below a normal winter.
If you own a dock, the lowest water isn't the date to plan around. The lake starts dipping below last winter's level in about two weeks, and the permits Tri-Dam asks dock owners to file move slower than the water does.
The week the lake leaves familiar water
For the week of September 30 through October 6, Tri-Dam's target band is 501 to 504 feet. Next week, October 7 to 13, it is 499 to 502, which is about where the lake sat all of last winter. Starting October 14 the target becomes 497 to 500 feet, and the low end of that band is already below last winter's floor. From October 21 on, the whole band sits below anything a Tulloch shoreline saw during the 2025–26 season. It stays there until the March refill brings the lake back to 498.6 to 501.6 feet.
Here are the key steps on the published schedule:
Dates | Target elevation | Change from the prior step |
|---|---|---|
Sept 30 – Oct 6, 2026 | 501–504 ft | About last winter's normal floor |
Oct 14 – 20, 2026 | 497–500 ft | Low end dips below the 2025–26 winter band |
Oct 21 – 27, 2026 | 495–498 ft | First week entirely below last winter's band |
Oct 28 – Nov 10, 2026 | 491–494 ft | 4 ft lower, the largest single step, held for two weeks |
Nov 11 – Dec 29, 2026 | Drops 2 ft per week | Ends at 477–480 ft |
Dec 30, 2026 – Feb 1, 2027 | 475–478 ft | Inspection and testing floor |
Feb 2 – Mar 8, 2027 | Rises about 4 ft per week | Refill begins |
Mar 9 – 19, 2027 | 498.6–501.6 ft | Back to normal winter elevation |
Two details in the table matter most for planning. The step on October 28 is the steepest on the schedule, and it comes right after the lake has already dropped below last winter's level. That makes late October the point where a dock set up for a normal winter is most likely to need attention. The refill is also faster than the drawdown. Tri-Dam says the February fill isn't governed by Army Corps of Engineers flood-control requirements, so "extra inflow will be retained rather than released," and storms can push levels well away from the listed ranges. The same caveat applies through the whole season. Tri-Dam says the reservoir will "generally be managed to the target elevation range," with some variation from large local inflows.
Tulloch has done this before, on a schedule
Deep winters at Tulloch come up when dam-safety work requires them. Tri-Dam's fall 2017 notice called that season "the year of the extended drawdown," set for "requisite dam safety inspections, testing and maintenance if needed." It expected the lake to stay at maximum drawdown for up to four weeks starting in early January 2018. The 2018 schedule bottomed out at 475 feet.
Three winters later it happened again. Tri-Dam's 2020 notice said state rules for cycling and inspecting the dam's gates had changed "from every five years to every three years." The reservoir reached 475 feet by January 3, 2021 and stayed there until January 9 while Tri-Dam ran the required inspections with state and federal officials. Before either of those, a spill-gate test in 2012–13 took the lake to 480 feet. In 2015 the lake was drawn down early to the same level, but for river-temperature management during the drought rather than gate testing.
The 2026–27 schedule doesn't say which inspections or tests are planned, and it doesn't name the agencies involved. The floor matches the 475-foot target from 2018 and 2021, but nothing published confirms the January 2027 work is the same gate test. Tri-Dam's Summer 2026 newsletter just calls it "a scheduled major reservoir drawdown." What owners can count on is the elevation, the dates, and the fact that the last two times the lake went this low, Tri-Dam asked shoreline owners to prepare months ahead.
What Tri-Dam is asking of shoreline owners
The newsletter gives this year's guidance in two sentences:
"Property owners are encouraged to inspect and secure all shoreline facilities, including docks, gangways, canopies, and other authorized improvements, to ensure they are prepared for changing water levels. If your facility will require low-water supports during the drawdown period, please submit your Low-Water Support Application as early as possible."
Tri-Dam hasn't published a 2026 filing deadline or fee for that application. The only precedent is the 2017 drawdown. That year, Tri-Dam asked for low-water support and excavation applications by November 1 "at the very latest." It explained that its own review could be quick, but state and federal permits "require additional time." The board also approved a $250 application fee for owners of already-approved facilities who wanted to install low-water supports and make no other changes. Those numbers are history, not this year's rules. They do show how long the process took last time the lake reached this level. A November 1 cutoff fell when the lake was still only partway down.
The rules behind the paperwork haven't changed. Under Tri-Dam's FERC license, any work at or below the 515-foot contour needs Tri-Dam review and authorization in advance. The 2015 Tulloch Reservoir Shoreline Management Plan counts repairing, maintaining, or replacing a structure in that zone as shoreline development. It says even minor projects need a Tri-Dam encroachment permit before work starts. In 2017, Tri-Dam also asked owners who planned to move a dock temporarily to coordinate first so it ended up in an "approved and safe" location.
The exposed shoreline in January can look like a good chance to fix a gangway footing or regrade a slope. Under the rules above, it's only a good chance if the permit already exists. The quickest way to find out what applies this season is to call Tri-Dam at (209) 965-3996 and sign up for its email updates.
Boats still go in at the same two places
The drawdown doesn't change where boats launch. Under Tri-Dam's aquatic invasive species program, motorized vessels can launch only at Tri-Dam-approved facilities. Launching from private property is "strictly prohibited," so a lakefront dock can't serve as a ramp at any water level. Banding "will continue consistent with the prior season."
- Drifters Grill and Marina is an approved launch facility. Tri-Dam tells boaters to contact it directly for access and hours, at (209) 785-9410.
- Tulloch South Shore Campground has a launch run by Tuolumne County. Its launch and decontamination station were open as of July 2, 2026. The campground number listed by Tri-Dam is (209) 630-1600.
- Every trailered motorized boat must arrive clean, drained, and dry, go through inspection and banding, and display a current Tri-Dam sticker or a day pass alongside the DMV mussel-fee sticker. Operators need a California Boater Card.
None of the 2026 notices say whether either ramp works at 475 to 478 feet. If you plan to have a boat on the water between Thanksgiving and early March, call the facility before you hitch up.
Two things that changed on paper this fall
On September 8, 2026, the Calaveras County Board of Supervisors adopted Ordinance No. 3234. The published notice lists all five supervisors as ayes. It repeals Chapter 20.10 of the County Code, titled "Tulloch Reservoir," because the chapter "duplicated and was subservient to the Tri-Dam Project's existing federal regulatory scheme." The repeal takes effect 30 days after adoption, which is October 8, 2026. The county's own summary sums up where authority on the water already sat. For drawdown questions about docks, permits, and launching, Tri-Dam is the agency to call.
Water quality is the other open item. Tri-Dam's site still shows the Department of Water Resources "Caution" warning for Lake Tulloch that was posted after reports of a possible algal bloom. Its August 17 update reported cyanobacteria but no detected cyanotoxins. The Calaveras County Water District reported non-detect results for cyanotoxins in raw lake water at the Copper Cove treatment plant intake on August 14 and said drinking water remained safe. No source so far says the caution has been lifted. Check Tri-Dam's public safety page before swimming or letting a dog into the water this fall.
If you're weighing a dock repair, a low-water support application, or how this winter's levels affect a lakefront property you own or are thinking about, Baxter Luxury Home Team can walk through the Tri-Dam calendar with you and help you get the timing right before October 28.
