Water clarity in Lake Tahoe reached a record low annual average in 2017 due to a historic drought, record-breaking precipitation and warmer than usual lake temperatures, according to a new study.
The average annual clarity level for 2017 clocked in at 59.7 feet — a roughly 9.5 foot decrease from 2016 — and surpassed the previous recorded low of 64.1 feet in 1997, according to a report released by the Tahoe Environmental Research Center at UC Davis.
“The combination of arguably the most extreme drought period ending with the most extreme precipitation year produced the low clarity values seen,” said Geoffrey Schladow, the research center director.
Media: Brandpoint The Tahoe Basin recorded roughly 300 percent of its normal precipitation, which was bolstered by an early winter storm in November 2017.
California was nearing the end of its worst drought in roughly 1,200 years in 2017 and recorded heavy rains.
Those rising temperatures coupled with unusually low wind speeds in July and August caused warm water temperatures to last through September, which is later than normal for Lake Tahoe.
The water clarity report suggests that warming lake temperatures help in holding sediment particles to the surface of the water for a longer period of time, causing a drop in clarity.
“It’s important to continue to make those smart investments for the long-term health of the lake and its environment.” Researchers with the Tahoe Environmental Research Center have been using water sensors, NASA buoys and manually collecting samples to help better understand under-examined areas of the lake during different weather conditions.
Clarity analyses efforts were funded through the Tahoe Regional Planning Agency and UC Davis.
Lauren Hernandez is a San Francisco Chronicle staff writer.

With the Colorado River Basin facing yet another year of water scarcity, the National Young Farmers Coalition brings young farmers from impacted states to Washington, D.C., to advocate for farm bill programs that promote drought resilience and enable a new generation of farmers to grow the nation’s food supply.
They’re here to fight for their livelihoods, and for the future of American agriculture,” said Erin Foster West, policy specialist for NYFC.
“As any farmer will tell you, June is a very difficult time to leave the farm.
That’s how important this Farm Bill is to their futures.
America’s farm population is aging rapidly, and hundreds of millions of acres of U.S. farmland will change hands in the next two decades.
There’s no question that our nation needs more young farmers, and young farmers need better support for drought and climate resilience, access to credit and affordable farmland, and opportunities for training and mentorship.” One such producer, Dan Waldvogle, a rancher and NYFC member from Colorado, will be coming out to D.C. to meet with his representatives as part of the fly-in.
It can be particularly difficult for beginning farmers to withstand these events.
I feel that it is extremely important that the 2018 farm bill have a hearty safety net and conservation programs directed toward creating resilience for the next generation of farmers and ranchers.
Among the legislators the farmers are scheduled to meet are members and staff of the Senate and House Agriculture and Natural Resource Committees including: Senators Michael Bennet (D-CO), Michael Gardner (R-CO), John Barrasso (R-WY), Martin Heinrich (R-NM), and Jeff Flake (R-AZ); as well as Representatives Scott Tipton (R-CO), Doug Lamborn (R-CO), Liz Cheney (R-WY), Michelle Lujan Grisham (D-NM), and Tom O’Halleran (D-AZ).
Visit NYFC on the web at www.youngfarmers.org, and on Twitter,Facebook, YouTubeandInstagram.

Steady winter rains over the last week have substantially eased Cape Town’s worst drought in a century, replenishing reservoirs for the western Cape region of South Africa to levels well above last year’s, officials said on Monday.
Dam levels have risen to 31.5 percent as of this week compared with just 21 percent the same time a year ago, said Rashid Khan, regional head at the water and sanitation department.
The drought has ravaged crops, hit tourist numbers and forced changes to consumption habits in Cape Town and surrounding areas as mandatory water restrictions were implemented.
We urge water users – domestic and industries – to continue using water sparingly,” he said, adding that it was too soon to ease a limit of 50 litres a day for domestic users, which has helped to halve consumption since 2016.
“We urge water users – domestic and industries – to continue using water sparingly,” he said, adding that it was too soon to ease a limit of 50 litres a day for domestic users, which has helped to halve consumption since 2016.
Day Zero explained Day Zero will be the start of active water rationing.
As far as possible, drinking water will continue to be supplied to some critical areas.
It also means that a portion of water collected from the distribution points will have to be used, for example, to flush toilets.
This will be impractical and hugely challenging at the very least.
Site selection is unlikely to be evenly distributed across the city because distribution sites will depend on existing water pipelines.

The worst drought in living memory has hit vineyards in South Africa’s Western Cape hard, reducing grape harvests and adding to pressure on the region’s centuries-old wine industry, officials said on Tuesday.
In its latest wine harvest report, industry body Vinpro said South Africa’s wine-grape production was down 15 percent from last year, and would lead to a production shortfall of 170 million liters of wine and prices rising as much as 11 percent.
South Africa’s wine sector, which dates back to the arrival of the first European settlers in the 1650s, employs 300,000 people directly and indirectly and contributed about $3 billion to the economy in 2015, according to an industry study.
The government has declared the drought a disaster in the Western Cape, the country’s main wine-producing region around the tourist city of Cape Town.
Besides vineyards, it has decimated wheat crops and cut apple, grape and pear exports, most of which go to Europe.
Vinpro managing director Rico Basson said more than a third of vineyards were operating at a loss and overall numbers were shrinking as farmers uprooted vines to make way for more profitable fruit crops or simply failed to replace old vines.
Over the last decade, the amount of land used for growing grapes had shrunk by 9 percent, he said.
The problems in South Africa mirror those in other wine-growing countries and are likely to fuel concerns about changes in weather patterns as a result of global warming.
Globally, wine output fell to its lowest in 60 years last year due to unfavorable weather, especially in Europe, according to the international wine organization OIV.
In April, the OIV said South Africa, the world’s eighth largest producer, had produced 1.1 billion liters of wine in 2017, a 3 percent increase on the previous year.

Cape Town – At midnight on Wednesday, 31 January 2018, the extended comment window for the Water Amendment By-law was closed, with approximately 38 000 comments received from the public. The submissions will now be reviewed for constructive inputs, which will be considered for adjustments to the proposed By-law amendments. This process is expected to last approximately two months. The public will be kept informed of developments in this regard. The amended City of Cape Town Water By-law went for a first public comment period in 2016. However, due to Cape Town experiencing the worst drought in recorded history, and the City’s emphasis on proactive governance to better address water scarcity, it required further refinement. This updated version was drafted last year (2017) and advertised for public comment in early December. The amended By-law was open for public comment for more than a month which is beyond the statutory comment period requirements. The City thanked those members of the public who have familiarized themselves with the proposed amendments and engaged constructively with the content from an informed position. Given that there has been a fair amount of misinformation being shared among residents on various social media platforms, the City would like to remind the public that the proposed amendments are necessary to reflect and support the needs of the New Normal in which we find ourselves. These changes have not been proposed as a means to control or restrict what residents are doing to save water, but rather to put measures in place that support these interventions in a manner that protects public health, ensuring we are a more water efficient society going forward and that our built environment supports our broader efforts to live more sustainably. The points below provide clarity on some of the popular misinterpretations of the content of the Water By-law: ‘The By-law will force you to have plans for your Jojo tanks’ Where households have Jojo or any other kind of rainwater tank installed and are only using…