As of Saturday, May 7, Caltrans had plowed as far as Tioga Lake, a little over a mile from the Yosemite National Park entrance at Tioga Pass. Highway 120 remained closed at the winter closure gate four miles from Highway 395. Even the cleared portion of the roadway still had areas that were narrow and need additional snow clearing. From the west, you can track the National Park crew’s progress here.

On Saturday May 7th, a small crew was working on widening the cleared area just above the green bridge. Note the waterfall on the left indicating that Ellery Lake is spilling.

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April in the Mono Basin was near-average, but slightly on the cool, dry, and windy side when compared to recent years. Although the high temperature on April 1st was 72 degrees F, the last two weeks struggled to get out of the 50s. It was our windiest April since 2004, with an average wind speed of 4.9 mph in Lee Vining. The 58 mph high-wind-gusts this April and last April were not out of the ordinary. You can see our April weather log here.

This year April brought wind, cool temperatures, and average precipitation to the Mono Basin. Photo by Arya Degenhardt.

Lee Vining precipitation in April was (more…)

Ever since NASA broke the news in December about the discovery of a bacterium from Mono Lake that appears to use arsenic in place of phosphorous, we’ve been talking fairly often with Dr. Ron Oremland, one of the lead scientists from the US Geological Survey working on the team. He has studied Mono Lake for decades and knows its microbes and chemistry well. He answered our questions about the discovery so that we could write an article about it in the Mono Lake Newsletter and accurately interpret it for the public, and he sent us a batch of his scientific papers related to Mono Lake and arsenic which we’ve posted on the Mono Basin Clearinghouse.

Ron will be speaking on Tuesday April 26th at the Sierra Nevada Aquatic Research Laboratory (more…)

Every April, after the April 1st snow surveys are in, the Los Angeles Department of Water & Power (DWP) issues a preliminary April 1st runoff forecast, and then a final forecast update in May. The April 1st forecast for the Mono Basin for the April 1 2011–March 31 2012 runoff year is 147% of average!

We always get asked why the runoff forecast is different than the snowpack—if the snowpack is 169% of average, shouldn’t the runoff be the same? The simple answer is that the snowpack is extremely variable, and some of it soaks into the ground or sublimates into the air—so not all the water in the snow becomes runoff.

Since the State Water Board decision in 1994, only two years have had more than 147% runoff (more…)

On April 19, 2011, the Lee Vining WebCam moved from its long-time home looking out the attic vent above the Committee’s front door to the top of the roof, about two feet below the anemometer. The vent will be closed as part of the remodeling of the front of the building, which will begin this week (watch for a Mono-logue post about that coming soon).

In its former location, the WebCam captured (more…)

The April 1st snow surveys in the Mono Basin found 169% of average snowpack in the headwaters of Rush Creek and Lee Vining creeks. Snow water content ranged from 133% at Gem Lake to 187% at Ellery Lake.

A typical spring day in the Mono Basin: snowstorms edging their way over the Sierra Nevada. Photo by Arya Degenhardt.

The March storms were relentless, with only nine days during the month when the Gem Pass snow pillow did not record an increase in snow water content. In Lee Vining it was our wettest March since 1995, with over 4 inches of precipitation. It was our snowiest March on record (since 1989), barely beating March 2001′s 43 inches of snowfall by 0.8 inches.

We are still waiting for the Los Angeles Department of Water & Power to release the preliminary April runoff forecast (to be finalized in May), but based on the snowpack, it might be a similar runoff year to 1998, 2005, and 2006—somewhere in the 140–150% of average range. We’ll post an update when we have more information—but Mono Lake will definitely rise a lot this year!

Now available on the Mono Basin Clearinghouse are the 1996 restoration plans that have guided restoration in the Mono Basin since they were implemented under Water Rights Orders 98-05 and 98-07 in 1998. Not everything in these plans was ordered as written—to understand the current restoration requirements, a (more…)

In December, after we posted links to papers by Ron Oremland with the US Geological Survey, Ron sent us a few more references. These are now available here on the Mono Basin Clearinghouse. He also included a few references from lakes with similarities to Mono Lake, such as Big Soda Lake in Nevada and Searles Lake, California.

This brings us to 40 scientific papers or abstracts related to Mono Lake or arsenic that can be downloaded from this page.

Mono Basin March 1st snow surveys aren’t all in yet, but so far surveys in the Lee Vining Creek drainage have been completed. In percent of the April 1st average snow water content, Tioga Pass was 105%, Saddlebag Lake was 110%, and Ellery Lake was 128%. This averages 114% for April 1st and 134% for March 1st.  Statewide, so far the totals are 109% for April 1st and 124% for March 1st, and ranging from 66% for the Scott River to 225% for the Tule River (March 1). The basins adjacent to Mono (more…)

In 1994, the State Water Resources Control Board issued Decision 1631, restoring Mono Lake and its tributary streams through a plan of reduced water diversions to Los Angeles. At that time, the decision considered LA’s water supply projections:

The Los Angeles Department of Water & Power (DWP) projects that the city will use approximately 700 thousand acre-feet per year by 1995, increasing to 756.5 thousand acre-feet by 2010 due to population growth. DWP cautions, however, that large uncertainties exist regarding future projections.

The decision went on to (more…)