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Part I: Nature, man create dicey outlook

This is the first in a three part series examining north and central Tuolumne County’s drought crisis, how we got here and where we’re headed. 

 The irony of this year’s drought situation is abundantly clear at Lyons Reservoir near Sierra Village, one of two main water sources relied upon by 44,000 Tuolumne County residents.

Thousands of gallons of pristine High Sierra water each day thunder over the dam unused. Meanwhile, downstream in Twain Harte, Sonora and Jamestown, lawns brown, flower beds wilt, restaurants withhold water unless requested and toilets go unflushed.

Any casual observer might rightly wonder, what gives? The conspiracy minded might even question if there is truly a drought, or if it’s as bad as it was billed. 

The answers are complex and maybe even counter-intuitive, but illustrate more effectively than maybe any time in county history just how tenuous the water supply for 80 percent of the county’s residents really is.

Yes, there’s a natural drought. This year’s rainfall was half of average, and the snowpack about an eighth what it normally is. But the problem goes even deeper.

Tuolumne County lacks storage — it’s largest water agency borrowing water and storing it behind a pair of dams it doesn’t even own or control.

The county also has historically lacked a common vision or plan for water use. The largest water purveyor, Tuolumne Utilities District, is just two decades old and adopted a hodge podge system of old tanks and bare dirt canals built to deliver water to gold miners’ pans, not residential homes.

Compounding matters, the county is suffering a double whammy of a natural drought and a man-made one, brought on by regulations drawn up during normal rain years to serve boaters, anglers and swimmers.

For all such reasons, the state Office of Emergency Services ranks Tuolumne County as one of the top three California counties most impacted by the drought, said Deputy Tuolumne County Administrator Tracie Riggs, who acts as a liaison between the county government and OES on drought issues.

End of spill

It may be mind-boggling, but the water flowing over Lyons since April is a normal state of affairs. The engineers at TUD even have a name for it — it’s aptly called “the spill” and it means the reservoir is filled to the brim. Which would seem promising, except “the spill” this year is expected to end more than a month early. Estimates are early next week.

The so-called “end of spill” event signifies when the snowpack upstream of Lyons and Pinecrest reservoirs has completely melted, ending the overflow of water into Pinecrest and Lyons. It’s almost always around mid-July, which is good since that slow snowmelt keeps the reservoirs filled through fall.

The exact date of the spill’s end is a moving target. Variables affecting an accurate estimate include how fast the remaining snow in the South Fork Stanislaus River watershed melts and how much of the water is absorbed by the soil, already super dry from two previous drought years.

Glen Nunnelley, a TUD engineer, daily checks for updated readings from a sensor that measures the flow of water in the South Fork of the Stanislaus River between Lyons and Pinecrest reservoirs. He also closely watches temperatures, snowpack surveys and general climate forecasts and compares the current information with historical data.

Nunnelley said this is the driest year he’s seen since he started working at TUD six years ago, and also the driest since the district was formed in 1992.

“We have not monitored the weather and flows this close before,” he said.

When the spill ends, TUD’s customers will be coasting almost solely on the water stored behind Lyons.

This summertime coasting is the norm, but happening a month and a half early could leave the county short. It’s like running out of gas just before you reach home. If you’re 75 yards, and you play your hand right, you should barely be able to roll into your driveway. But run empty at 100 yards, and you may be pushing your car for the next 25.

In terms of this year’s water supply, that means if TUD’s customers this summer use what they typically use, the district will run out of water by early August.

“We’ve got a mathematical problem, but the list of knowns is much shorter than the list of unknowns in this equation,” is the way TUD General Manager Tom Scesa put it.

Natural drought vs.
regulatory drought 

Sonora has received just 16 inches of rainfall to date, compared to about 15 during the 1977 drought — the benchmark used by TUD to compare dry years.

The average annual rainfall is about 32 inches, and that mostly falls from November to April.

The snowpack is no better this year. The state Department of Water Resources’ final manual snow survey of the season on May 1 showed the water content in the snowpack statewide was less than 20 percent of normal for that date.

NASA satellite imagery sent to TUD in late-April showed the snowpack in watersheds critical to the district was about 18 percent of normal.

Early indications this year’s snow totals would be below normal prompted the state, county and TUD to take action early.

In January, Gov. Jerry Brown declared a drought-related state of emergency statewide. Tuolumne County likewise declared an emergency. The effect of the declarations was to begin freeing up money to pay for drought-related expenses, like well drilling and water filtration.

The skimpy snowpack above Pinecrest and Lyons was particularly disconcerting because, like most of California, the annual water supply for residents and businesses who rely on TUD is determined by the size of the Sierra snowpack. There’s just not enough storage space available to meet the district’s needs.

Lyons holds 5,500 acre-feet and Pinecrest 18,000 acre-feet. There are two other small reservoirs — really holding ponds. Matelot is located on Big Hill above Columbia and Phoenix Lake is just upstream of Sonora and below Lyons.

Combined, all four hold about 24,500 acre-feet.

An acre-foot is enough water to cover a football field 1 foot deep, or enough to meet two average families’ needs for a year. 

TUD’s customers each year use about 17,000 acre-feet. So in a normal year, there’s water left over. But it’s spoken for, because Pinecrest and Lyons are not actually owned by TUD.

Pinecrest, built in 1916, and Lyons, built in 1930, were built primarily not to store drinking water but to produce power. Both reservoirs are still part of Pacific Gas & Electric’s Spring Gap-Stanislaus Project.

TUD gets its water for free under a contract with PG&E, which only needs the water as its being run through its generators.

The system has served the county fairly well in past average and above-average precipitation years, but more delicate in dry ones, as TUD has to rely on PG&E’s generosity and regulatory constraints in determining when and how water to moved through the system.

“If we had complete control at Pinecrest, the need for conservation would be significantly less,” Scesa said.

One such operational constraint, in 2008, PG&E had to renew its federal license to operate Pinecrest and its hydroelectric powerhouse. A condition of the Federal Energy Regulatory Commission renewal required PG&E to maintain the level of Pinecrest at 5,608 feet above sea level until Labor Day. This ensures an enjoyable summertime depth for campers, cabin owners and day trippers boating, fishing and swimming in the lake.

So from the “end of spill” until Sept. 1, TUD customers must rely on the 5,500 acre-feet of water stored in Lyons — and only about 4,000 of that can be used as drinking water. After it drops below that amount, the water becomes too murky and contaminated to effectively clean.

TUD staff describe the situation as a “regulatory drought.”

“That’s an interesting set of operational constraints. When the ‘end of spill’ happens each year, it triggers all these cascading series of events,” said John Mills, a former TUD consultant and a leading state water expert.

The district was forced to apply for an exemption to the rule in 2012, another exceptionally dry year, when the spill ended on June 10. The state water board granted the exemption to draw the lake down an extra 2 feet, with the caveat that TUD had to implement mandatory water-saving measures through Labor Day.

The district is seeking another exemption this year.

But such exemptions are stopgap measures, and fail to address the underlying issues: lack of storage, lack of control and, also, a lack of diversification — all the district’s water coming from one watershed.

“It’s kind of like every year is a gamble,” Nunnelley said.

Conservation measures

Dry conditions, a lack of long-term storage and the aforementioned regulatory drought prompted TUD last winter to implement what are among the toughest water-conservation measures in the state.

In arid Southern California, residents aren’t confronted with the strict conservation steps implemented by TUD. Customers of San Diego’s and Los Angeles’ main water districts are being “asked” this month to “conserve” water. Lisa Lien-Mager, with the Association of California Water Agencies, chalks it up to diversification and planning. San Diego, for example, can access water from the Colorado River as well as Northern California.

TUD’s January restrictions include a mandatory 25 percent cut in usage for each customer and a ban on lawn watering. There are even tougher restrictions on agricultural users, like 50 percent cuts to water deliveries for irrigation.

Conservation steps are even tighter in communities like Twain Harte, where people get water from a TUD contractor, the Twain Harte Community Services District.

TUD has cut this year’s deliveries to raw-water customers, like THCSD and Mi-Wuk Village Mutual Water Co., in half. Those agencies will have to pass some if not all the cuts to customers.

TUD and Twain Harte’s customers have so far responded to the calls for conservation. TUD customers as a whole used about 32 percent less in April over the same month in 2013, according to district officials.

In Twain Harte, some residents and businesses are changing daily routines to cut down on water use and spending hundreds of dollars to replace old appliances with newer, water-efficient models. The China House restaurant, for example, had to eliminate one of its buffet nights because those produce three times the amount of dirty dishes as normal dinner services.

In addition to drastic conservation measures, Tuolumne Utilities District also drew up a crazy quilt contingency plan for backup water supplies that included pumping water from an abandoned mine shaft, reviving old wells and buying water from a small American Indian tribe in Jamestown that had the foresight to arrange a deal with farmers in Manteca to buy water they claim out of the Stanislaus River.

Most of those plans are progressing, albeit slowly.

The abandoned mine shaft plan was dropped because TUD needed to borrow a portable water treatment plant from Groveland Community Services District to clean the contaminated mine water. GCSD, which gets water from an entirely different source — the Tuolumne River — declined because it may need the plant to filter its own backup water source, Cherry Reservoir.

A second backup source: The Chicken Ranch Rancheria of Me-Wuk Indians. The tribe early this year secured a contract with the South San Joaquin Irrigation District to buy 2,400 acre-feet of water out of New Melones Reservoir — enough to supply roughly 4,800 families of four for an entire year. The TUD board last week agreed to buy the water from the tribe at cost: about $200 an acre-foot.

Also, the district has constructed water treatment plants to filter groundwater coming out of recently reactivated old wells that will serve residential areas for the first time in years.

TUD construction crews recently built a plant at the Mill Villa well and applied for a $400,000 grant from the California Public Health Department to cover the costs. 

Seeing such conservation and backup steps in place, and cringing over the spill at Lyons, some TUD customers question the direness of the drought situation now.

Noting the Lyon spillage, TUD board member Mike Sarno wants to lift the ban on lawn watering. He’s got support from the Tuolumne Parks and Recreation District, which says it’s looking at a loss of about $400,000 to replace more than 140,000 square-feet of lawn expected to die if the ban carries into summer.

Sarno at a recent board meeting warned that the district’s “ultra-conservative” approach could backfire.

“It will be both financial disaster for us and a slap in the face when we get to September and everyone has brown lawns,” he said.

The rest of the board voted to keep the ban in effect for the time being until more is known about the end of spill and whether the state will allow the district to draw extra water from Pinecrest this summer.

Scesa said the lawn watering moratorium was intended to prepare customers for the end of spill. It’s conservation made easy, as about half an average household’s annual water use is consumed by lawns.

Customers who let their lawns die this summer won’t have to do much more to meet the district’s conservation mandate and avoid any fines, he explained.

When the restrictions were first implemented in late-January, the snowpack was at historic lows and it was uncertain whether there would even be enough runoff to fill Lyons and Pinecrest reservoirs.

Should the district have eased off a bit when it became clear the reservoirs were going to fill, which didn’t happen until mid-April?

“Hindsight’s always 20-20,” Scesa said. “Would I have rolled it out a little different? Possibly.”

“Still, I’m comfortable it was the right decision,” he added. “We have this great variability on the end of spill and whether we can get water from Pinecrest. I’m still stuck trying to make sure we have enough water for health and safety this summer.”

Despite early and ongoing conservation, and the bevy of contingency plans, there are no guarantees.

The district, formed after the last major drought in the early 1990s, is in uncharted water.

The only other alternative if the supply doesn’t last would be to import water by the truckload. Scesa said he doesn’t even know what that would entail or how it all would work, but the state Office of Emergency Services would likely be involved.

Scesa’s talked with trucking companies and the OES to evaluate the potential for doing so.

All of the contingency plans have at least ensured the district will have “some elasticity left, but not a lot” after the spill ends at Pinecrest, Scesa said.

Right now, there are just still too many “unknowns” for Scesa to be absolutely certain — and he knows an entire community’s water supply hangs in the balance.

 

“It will be more of a relief when we get to Labor Day,” he said.


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Thu, 27 Nov 2014 19:27:51 -0800