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Just took a look at current lake levels up at Oroville (I am about 20 miles downstream from the dam):

https://oroville.lakesonline.com/Level/

Water levels are going straight up like a rocket, with a LOT of rain in the forecast over the the Oroville Dam watershed. Looking at the graph on the above page, it looks like the water level has not come up this fast, in so short a time, in many years.

As I have said before, my house is about a mile from the Feather River, but flooding in my area from the river really isn't a concern. . . unless and until water releases begin up at Oroville. That probably won't happen anytime soon. . . but it could, if the rains - and the intensity of the rains - over the watershed continue.

Just checked river levels near my house, no where near flood stage at the moment. . . but that could change, of course.

Keeping my eye on things!

On Edit: Oops! Looks like water releases have begun (this statement is of January 6), and are set to continue:

"The Feather River releases are currently at 950 cubic feet per second (cfs). Flows through the City of Oroville are 650 cfs with 300 cfs released from the Thermalito Afterbay Outlet (Outlet) for a total of 950 cfs downstream of the Outlet. DWR continues to assess releases to the Feather River daily."
https://water.ca.gov/News/Blog/2023/Jan-23/Oroville-Update-1-6-23

1 cubic foot = 7.48 gallons, so 950 cubic feet per second released is 7,106 gallons per second currently being released into the Feather River. Actually, not all that big of a release as such things go - but I need to keep my eyes on this, as it is likely to increase. Gallons per minute at this rate is 426,360, gallons per hour at this rate is 25,581,600.

LOL. Try to imagine 25 million gallon milk jugs per hour floating and bobbing down the street in front of your house.

Sue, maybe you better leave the lights on for me after all!

Anne

Why are they releasing water? Is it for agricultural use? Or because they don't want the lake to get too full?

I checked the Napa River on my way back from dropping my motorhome off at the repair place. It is full, but not flooded, and they have opened the flood gates near what they call the "oxbow." This is a big loop of the river that they allow to flood to take the pressure off the main river. The area stores the water, though closing the flood gates causes a couple of roads end up being closed.

Also, just checked the drought monitor and nearly all of California has advanced one category in terms of drought. https://droughtmonitor.unl.edu/

JudyJB wrote:Why are they releasing water? Is it for agricultural use? Or because they don't want the lake to get too full?

Thanks for the question, Judy. It give me the opportunity to pontificate a bit, which I am never loath to do!!

Judy, I can't speak directly for DWR (California Department of Water Resources), and precisely why they have begun to do water releases at this time.

Short answer? Yes, you are correct - basically, because they don't want the lake to get too full. But this is not as simple an answer at it might seem.

Longer answer:

I know from long experience living downstream of Oroville dam, and of doing research, is that DWR (usually!) tends to look closely at weather predictions and to take the "long view" of possible upcoming weather events. I think they do this more carefully these days, after the failure of the Oroville Dam spillway in 2017, when around 200,000 people were evacuated because it was feared the emergency spillway might fail.

DWR is involved in a very tricky and complicated business (to spill or not to spill, that is the question!) when considering, and/or initiating water releases.

In looking at http://www.weather.com (the United States National Weather Service website - my personal "go to" weather website) I can see that rain is predicted for the city of Oroville every day over the next week, and possibly beyond.

I am not DWR, and just looking at the weather predictions for the city of Oroville does not nearly give the entire picture and complexity of what is going on. (Oroville Dam is just east, and slightly north, of the city of Oroville).

The Oroville watershed (a watershed is the area of land that drains water into a lake) spans somewhere around 3,500 - 4,000 square miles - so DWR is probably not generally concerned by the amount of rain falling in the valley so much (and falling in the city of Oroville, or over the lake itself) as it is of the rain falling/or might fall over the entire watershed.

The concern is the amount of rain falling over the lower and upper regions of the Sierra foothills, and beyond (again, a mountain watershed comprising of more than 3,500 square miles).

It generally rains a LOT more over the mountains and foothills than it does in the valley (i.e., the city of Oroville) - although rainfall is, of course, variable. A good example might be that during a very heavy rainfall, a half inch or so of rain might fall in the city of Oroville (which is a valley city), in the Sierra foothills over that same day 1 1/2 inches of rain might fall from the same storm.

Another complicating factor is if a lot of snow has fallen over, say, several weeks over the upper foothills of the watershed (which, as of this writing, it has) - maybe accumulating many feet of snow - if a warm weather system then hits this snow as rain (because the storm is warm), it can melt these many feet of snow accumulation all at once - often within a few hours.

Of course, then sending all of that rushing water that once was snow on down towards the lake.

Also, within that watershed's 3,400 - 4,000 square mile "footprint" are many other, smaller dams. As these smaller dams also begin to fill to capacity, they too will need to do water releases - sending ever more water down into Oroville dam.

For DWR, it is a balancing act. And DWR does not have a crystal ball.

Release too much water, and they look like fools for not conserving water if the rains should suddenly stop (which they can and do). Release not enough water, when heavier, more intense rains than predicted arrive, over a longer period, disaster might strike (as it did in 2017). So they look like fools, and are in for public condemnation, for not releasing enough water.

The "long answer" is actually quite a bit more complicated than what I write here, but I can feel everyone's eyes glazing over at the length of this post. So I will bring this post to a close.

Thanks for asking, Judy.

Anne

My eyes didn't glaze over. Unfortunately it's science and a guessing game all at the same time.

Bethers wrote:. . . Unfortunately it's science and a guessing game all at the same time.

Yes, Beth! You are precisely correct!!

Here is a fun graphic that may (or may not!) help bring the Oroville Dam watershed more into focus for everyone. This map shows many of the larger dams within the watershed - that will also release water down towards Oroville Dam as they fill - there are also additional, smaller dams that do not show on this map):

(The Feather River watershed is in yellow - Lake Oroville is on the left, a bit up from the bottom). Lake Almanor is one of the larger dams that drain to Lake Oroville within the Feather River watershed:

https://cw3e.ucsd.edu/FIRO_docs/images/Yuba_Feather_Fig1.png

On Edit: Here is another "fun fact". The base of Oroville Dam is about 167 feet above sea level. Lake Almanor is 4,505 feet above sea level.

Lots of drainage from high to low elevations here in the Sierra!

Anne

They are saying that the next system over the weekend and into next week will be a lot worse than the one this past week, so that is probably why they are releasing water at this point, among the other reasons you stated.

BarbaraRose wrote:They are saying that the next system over the weekend and into next week will be a lot worse than the one this past week, so that is probably why they are releasing water at this point, among the other reasons you stated.

The amount of water currently flowing into Oroville dam (inflow) as of this morning, 1-13-23 @ 10:00 a.m is 23,921 cfs (cubic feet per second), as per the California State website that monitors this: https://cdec.water.ca.gov/dynamicapp/QueryF?s=ORO&

I think I have these calcs correct, using the calculator at: https://www.kylesconverter.com/flow/cubic-feet-per-second-to-gallons-(us-fluid)-per-minute

23,921 cfs is equal to 10,736,490 (ten million +) gallons per minute, which is equal to 644,189,400 gallons per hour (six-hundred forty-four million +).

Whole lotta water comin' into the dam upstream of me.

According to the lake level monitor, https://oroville.lakesonline.com/Level/ as of 1-13-23 @ 10:45 a.m., the lake level stands at 763.7 feet. The lake level has been rising just under five feet per day since January 2.

Oroville lake is, I think, the second-largest lake in the state of California (after Shasta Lake). For the water levels to rise so fast on a lake this large takes a truly incredible inflow of water. Which, I guess, we are seeing right now.

With more to come: rain in the forecast over the next several days, sometimes heavy rain.

Now, where did I put that Go Bag, anyway?

Anne

Should I get my guest room ready? That is a bit concerning.

Colliemom wrote:Should I get my guest room ready? That is a bit concerning.

Sue!! Thanks!! Found the Go Bag!

Please leave the light on for me!!

Anne