California rivers are so swollen from runoff that the impact is easily seen in these before and after satellite images

ImaGeo iconImaGeoBy Tom YulsmanFeb 12, 2017 5:08 AM


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An animation of satellite images taken about a year apart shows a huge difference in the amount of water flowing through waterways in California's Sacramento River Delta. (Images: NASA Worldview. Animation: Tom Yulsman) [NOTE: PLEASE SEE UPDATE AT THE BOTTOM ABOUT THE OROVILLE DAM] This animation of satellite images shows in dramatic fashion just how far California has come following one of its most devastating droughts on record. To get the full effect, make sure to click on the animated GIF. On Feb. 9, 2016, California was still in the grips of the drought. At that time, the waterways of the Sacramento River Delta were barely visible from space, as seen in the first image of the animation, acquired by NASA's Aqua satellite. The second image, acquired today by Terra, Aqua's twin, shows those waterways swollen and laden with brown sediment. Also take a look at the coastal waters. The animation reveals that a lot more sediment is flowing into the ocean than a year ago — because so much more runoff is flowing out to sea. | Story updated 2/13/17 with this new animation:

A closer before-and-after satellite view of the Sacramento River Delta area. One image was acquired by the Aqua satellite on Feb. 8, 2016; the other on Sunday, Feb. 12, 2017 by Terra, Aqua's twin. The Sacramento River Delta is downstream of Lake Oroville, the massive reservoir to the north where severe erosion of the emergency spillway prompted evacuation of 188,000 people on February 12th. (Images: NASA Worldview. Animation: Tom Yulsman) | In fact, there's so much runoff from the huge amount of precipitation California has received in recent weeks that the Sacramento Bee is reporting this

After five years of drought, could California really have so much rain and snow there’s no room to store all the water? The answer – as the state’s water picture careens from bust to boom – is yes.

The Oroville Dam north of Sacramento actually overflowed today, with water topping the emergency spillway. The California Department of Water Resources emphasizes that there is no risk to the dam, or of flooding downstream along the Feather River at this time, and there is no imminent threat to the public. Nonetheless, this is pretty dramatic: This is drone video, shot just this morning, of water pouring over the dam's auxiliary spillway. The reservoir is at 149 percent of the historical average for Feb. 11. Water pouring into the Feather River from Lake Oroville is making its way south into the Sacramento River Delta and adding to the flows there that have become visible from space. UPDATES: Since I first wrote this post, Lake Oroville's emergency spillway eroded severely, threatening massive flooding downstream. I'll be posting updates on the situation here.Feb. 13, 9 a.m. MST: 

Since ordering evacuation of about 188,000 people downstream, Lake Oroville's level dropped enough to stop the flow over the emergency spillway. Crews have been filling large, 1-ton bags of rocks and plan to drop them by helicopter into the spillway to temporarily repair the damage. Meanwhile, California's Department of Water Resources is hoping to drop the lake level by 50 feet over the next few days in an effort to make room for new water expected to pour into the reservoir from a storm forecast for later in the week. 

Here's a great aerial view of water pouring over the emergency spillway before it stopped last night:

Also, this failure of the spillway to work as intended should not have been a complete surprise. The San Jose Mercury News is reporting that 12 years ago, federal and state officials ignored warnings that this could happen. 

Feb. 12: Less than a day after the DWR said there was no risk to the emergency spillway and everything was under control, everything has, in fact, changed. Today, Sunday, the earthen spillway suffered extreme erosion and became at risk of total failure. This prompted the evacuation of 130,000 people downstream to protect them from the potential for catastrophic flooding. As I am writing this at 10:30 p.m. California time, the situation is unclear. But there is a glimmer of good news: On Twitter, the Sacramento Bee is reporting that the DWR says water is no longer flowing over the spillway. By morning, we'll know more. I'll check in then and provide an update.

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