I discussed Lee Vining Canyon / Hwy 120 status in Sierra Snowpack, Hwy 120 Status a few days ago.
The melt of the all-time record winter of 2016/2017 Sierra Nevada snowfall is well underway, with flooded meadows and loads of mosquitos in the lower-lying areas where creeks and rivers overflow. And yet it has not been particularly hot, so that water flows are likely to increase from here into July, possibly doing major damage in a few places. Things should settle down by late July, but crampons and ice axes will be needed for high passes late this year (the 50-foot-deep snowpack will not all melt in many places at 11,500' on up), a strange oddity.
A hot spell could dump uncontrollable volumes of water into area reservoirs. Some are being held low with maximum water being allowed to flow through for just that eventuality (Ellery Lake, Lundy Lake, perhaps Saddlebag Lake, Crowley Lake). Other like Grant Lake are already at capacity and have zero buffering capacity remaining. Area rivers are flooding the surrounding land in many places.
Grant Lake is one of three closely-grouped lakes just south of Lee Vining, CA (east of Yosemite), and southwest of Mono Lake. It is the largest and lowest of the three lakes in the June Lake loop: June Lake, Silver Lake, Grant Lake. The creeks into Silver Lake such as Rush Creek are within 8 inches of inundating the road with zero culvert flow capacity remaining (my personal assessment). The runoff from Silver lake flows into the far larger Grant Lake via Rush Creek.
Below, Grant Lake is dumping excess water down its long-unused overflow spillway. A place I parked my car last fall at the other end of the lake is now 30 feet under water. This spillway has been dry for many years AFAIK, but no longer. A fall into that spillway would be quite some ride... when some kid there rolled a 50 pound rock into the gently-sloped part of the spillway, it thumped along merrily—tremendous force.
Most images that follow taken with the iPhone 7 Plus in panorama mode. The iPhone in pano mode is by far the best camera choice for this type of shooting—even off a bike—because one can capture a very wide range of image widths at very good quality up to 17000 pixels wide or so. Downsampled to 50% to 75% linearly, the quality is strong, at least with the 1x camera, the 2X being marginal but useful nonetheless (still photo mode image quality ranges from marginal to garbage depending on lighting). See iPhone Panoramas In Depth: Shooting & Post Processing Tips, Numerous Examples up to 11K Resolution.
All this water is heading right for Mono Lake, which is seeing the largest influx of fresh water it has seen in many years—perhaps to be (unknown as yet) the largest influx in nearly a century. Other area creeks also contribute, such as Lee Vining Creek and Mill Creek from Lundy Canyon.
An enormous waterfull dumps snowmelt down Rush Creek from the Gem Lake / Agnew Lake area of the Rush Creek drainage into Silver Lake. The constant flow of (expensive) helicopter trips to the Gem Lake area suggest that that the LADWP is damn nervous about dam damage. The falls in Yosemite Valley are said to be spectacular, but I do not go to Yosemite Valley any more—it’s a mini city mess of noise and crowds.
To the north near the California/Nevada border, the Walker River is going gangbusters. It flows into Topaz Lake which appears to be at capacity. Downstream of this canyon area, several areas are flooded.