Waters at Lake Tulloch were about 30 feet lower Wednesday than the normal maximum level, as Tri-Dam personnel continue a scheduled, extended drawdown for safety inspections, testing and maintenance on the 60-year-old, 205-foot-high Tulloch Dam.
That means acres of rocks that are usually underwater and normal high-water marks about 509 feet above sea level are exposed, while docks designed to float are perched high and dry in the dry bathtub ring that stands between private waterfront homes and the reservoir below.
“Docks are not safe, and walking on docks will cause damage,” a Caution Keep Out sign says on a steeply sloping metal gangway leading from Drifters Marina & Grill down to wooden dock sections floating in a narrow cove below.
Under gray skies Wednesday, the overall picture at Tulloch made for a monochromatic, colorless scene.
Tulloch is drawn down so that dam gates can be fully tested and inspected to ensure they are all working the way they are supposed to, Susan Larson, license compliance coordinator for Tri-Dam, said Wednesday.
Homeowners, property owners and business owners who live and make their living on the manmade lake below New Melones Dam on the Stanislaus River understand the need for the drawdown, Jack Cox with the Lake Tulloch Alliance said Wednesday.
“We understand the lake has to be maintained,” Cox said in a phone interview. “Every five years they work on the electric generating turbines and other infrastructure. At Copper Cove they're working on improving the ramp.”
The Lake Tulloch Alliance represents about 500 residents of Calaveras and Tuolumne counties. Cox said the reservoir appeared to be down 35 feet on Wednesday. He said the visual display of how the reservoir looks when it’s so low is a strong reminder that people need strong water policy to ensure the same kind of drawdown never happens unplanned.
“We don't want water policy pushed on us by the state water board that puts fish first and people second,” Cox said, referring to state and federal efforts to improve habitat for native, migratory fish that predate construction of dams on the Stanislaus River. “The feds are rethinking all that policy since Trump's election.”
Short-term, Cox said, many Lake Tulloch residents and property owners are worried right now about the lack of precipitation so far this winter season.
“We've had very little rain and snow, and we hope it doesn't happen again like 2015,” Cox said. “The way the lake is right now is an illustration of why we never want to get to that point again.”
The sight of a popular reservoir touted by promoters for its recreation and real estate property values drawn down low in the wake of last year’s near-record wet winter underscores the artificial nature of Lake Tulloch and so many other man-made lakes in the Mother Lode and up and down the Central Sierra.
While major reservoirs in Calaveras and Tuolumne counties, including New Melones, Don Pedro and Hetch Hetchy, are all holding more than 80 percent of capacity this week, other reservoirs are drawn down for maintenance like Tulloch.
Cherry Lake, part of the Hetch Hetchy Water and Power System, is drawn down to minimum pool right now, just 2 percent of capacity, for repairs and maintenance work on high-flow release valves that was scheduled to begin in September. Motorized boats have not been allowed on Cherry Lake since Sept. 5.
San Francisco Public Utilities Commission staff say they hope normal rainfall and snowmelt will restore capacity at Cherry Lake by this summer.
Meanwhile, state water department staff and Tri-Dam people say Tulloch is holding 57 percent of capacity this week. Outflow at Tulloch on Tuesday was 1,539 cubic feet per second.
According to Tri-Dam, reservoir levels at Tulloch fluctuate on a daily basis and on a seasonal basis depending on the operating needs of the U.S. Bureau of Reclamation, which operates New Melones, and the needs of Tri-Dam, a partnership of the Oakdale Irrigation District and the South San Joaquin Irrigation District.
Where does the water go?
Water from Tulloch helps irrigate about 117,500 acres of land on farms in Stanislaus and San Joaquin counties. Tri-Dam staff say the irrigated land supports almonds, walnuts, grapes, pasture and truck crops.
During wet winters, reservoir levels are kept lower to provide flood storage space when needed. During summer, levels can fluctuate as Tri-Dam releases water to produce hydroelectricity. The Oakdale and South San Joaquin irrigation districts own the dam and powerhouse, and they have rights to the water stored in the reservoir.
The Calaveras County Water District has Copperopolis-area facilities that include water treatment and wastewater treatment plants at Copper Cove on Tulloch. Residential drinking water for Calaveras County Water District customers from Tulloch is not impacted by the current reservoir drawdown. The water district’s intake pipe is at 465 feet above sea level. That’s 10 feet lower than Tri-Dam expects to stop the current drawdown next week.
In the middle of March, the Bureau of Reclamation will publish a reservoir fill schedule for Tulloch and it will be distributed to Tulloch area property owners, Larson said Wednesday.
“During this time from mid-March to May, the reservoir levels are gradually increased and brought to full summer operating levels by Memorial Day,” Larson said. Asked for clarification, Larson said a Bureau of Reclamation schedule shows Memorial Day is the target date for having Lake Tulloch at full capacity.
Regardless of the reservoir level, a fundraiser for the Special Olympics of Northern California at Lake Tulloch is scheduled in late February.
The Lake Tulloch Polar Plunge is billed as a public event and it’s planned from 10 a.m. to 1 p.m. on Saturday, Feb. 24, at South Shore Lake Tulloch. At least 40 people have already signed up for the cold-water costume party. Participants are asked to raise a minimum of $125 to take part.
Contact Guy McCarthy at firstname.lastname@example.org or (209) 588-4585. Follow him on Twitter @GuyMcCarthy.