Interactive California Reservoir Levels Dashboard | Hacker News Reader

Interactive California Reservoir Levels Dashboard

engaging-data.com

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I find the official graphs easier to understand: https://cdec.water.ca.gov/resapp/RescondMain (it's also possible to pick dates to compare in adjacent tabs)

Doesn't provide the same sense of overall filled volume/capacity, though.

This is really great because it lets you compare to other years. It also really shows the uptick in fullness due to the recent storms if you click on a resevoir.

Sorry for the dumb question... but what does "historical average" mean, which years? Is it all years? A subset? If CA has been in a drought for so long, why is the historical average often higher?

Good question. I found this info on another page: "historical average level of the reservoirs at the same time of year (e.g. March 8th) between 1960 and 2010."

https://engaging-data.com/ca-reservoir-level/

As a quick warning, there are some very questionable ads displaying on that site. Please be careful of viewing at work.

ublock origin extension will fix that for you.

And Hetch Hetchy is here: https://waterdata.usgs.gov/monitoring-location/11275500/#par...

I'm assuming this dam is separate either because it is in a National Park and controlled by San Francisco.

Despite historical rains these reservoirs are still not back to their historical average levels. I'm guessing they will continue to rise as water flows down hill following the storms, but it is hard to get a sense of what is going on because the first derivative is not displayed.

It's all about the snowpack, and this makes me happy: https://cdec.water.ca.gov/snowapp/sweq.action

This visualization shows historical snow accumulation each month https://engaging-data.com/california-snowpack-levels/

Almost to 100%, so that's nice.

We've had several years where we had a very wet month then literally nothing after.

And hopefully we don't get any abnormally warm storms that melts some of that.

The same site's precipitation graph suggests that despite some recent precipitation, it's still only above average, rather than 'historic' for the period since last October:

https://engaging-data.com/california-precipitation-levels/

reservoirs aren’t low because of rainfall, they are lower than historical average because we use way more water now

Wow, there's a blue bar that goes off the chart: Whiskeytown reservoir, 102% capacity. Sure enough, that reservoir is filled to the brim and overflowed today into the giant Glory Hole: https://www.redding.com/story/news/local/2023/01/09/recent-r...

Afaik, whiskeytown is kept close to full all year since it's downstream of the trinity lake reservoir, which looks more like lake Oroville with exposed shoreline.

> The Glory Hole was a part of what she wanted to share

The author of this has to be pulling out leg

I don’t think you are supposed to put your leg in in the first place!

Englebright reservoir too

Looks like that one is designed to spill over the top. Fascinating. https://en.wikipedia.org/wiki/Englebright_Dam#/media/File:En...

Our largest local reservoir, Lake Cachuma, has gained 20000+ acre feet of water today which is something like 11ft of height.

BTW the author has one of the best FIRE (Financial Independence to Retire Early) calculators as well https://engaging-data.com/early-retirement-calculators-and-t...

I can't believe the timing of this link. I just watched a Wendover productions video on how NYC gets its water [0]. It was mindblowingly simple, but unimaginably expensive. Thanks for the link on California Reservoir. Can't wait to dig more on how this works.

[0]: https://www.youtube.com/watch?v=IDLkOWW0_xg

Snowpack is already at 85% of April 1st averages (and almost double the average for this point in the season). All of that snow will be melting in early summer. I expect they're going to keep the reservoirs less filled than usual in the Spring, to ensure there is capacity to avoid getting running into issues like Oroville reservoir did a few years back.

The problem is that the snowpack is part of the storage system. The warmer summers melt the snowpack sooner in the year, reducing the amount of water being stored. I've hiked in winter snow in August, and even September, but not for a few years.

We survive that because the reservoirs are designed to hold more than a year's worth of water demand. But the integrity of the system depends on all the parts operating to some degree.

The legend uses the word "Filled". "Filled" means "containing as much or as many as is possible or normal. Opposite of empty." A better term for the legend might be "current level"?

Does anything like this exist for the whole world?

I am sure there is, it is such an important thing, but I do not know / cannot find it. Anything from UNO / NASA / EU / whatever org?

How much of this is due to climate change and can be solved by ending fossil fuel use, and how much is due to agricultural irrigation?

Not an answer to the question but an aside related to it: After driving around in the Central Valley and looking at the massive agricultural industry there, it becomes very apparent that we're pumping a significant amount of water out of the ground and allowing it to evaporate into the atmosphere. I wonder how all of this additional moisture is impacting climate change as well. The scale of it all leads me to believe it's not insignificant, and the Central Valley is not the only place where this goes on.

In order to earnestly evaluate the meaning of `% of capacity`, we really need the stdev of the mean.

Side note - Most of CA reservoirs do not allow human contact. Meaning, no swimming, tubing, skiing, wakeboarding, etc. It stems from an archaic law before all potable water sources were filtered. Big bear reservoir and Lake Nacimiento, for instance, are specifically allowed for human contact in the law.

Personally, I wish we could open up all the reservoirs to all recreation.

[0] https://www.kqed.org/news/11780692/why-cant-you-swim-in-most...

Admittedly I haven't been to all lakes in California, but one time I went to Lake Shasta to do house boating for a week, and nearly every beach we landed on/near was littered with everything from old tires to car batteries to shotgun shells, plus the usual food/drink garbage.

I'd personally rather not allow "all recreation" in reservoirs used for drinking water.

Here’s the thing, all these reservoirs still allow boating, camping, etc, which contribute to the problems you're mentioning. They are already allowed. I’m just saying, it’s silly to not allow swimming as well. If you’d like to ban reservoir contact in totality, that’s one thing, but to not allowing swimming in the lake while all other activity is alllowed is just ridiculous.

That’s bay are drinking water reservoirs - which are not “most of CA reservoirs”.

Just look at the parent website, all of the largest reservoirs listed there, and most of the others, allow swimming and water recreation.

If you read the citation and subsequent law, it’s most CA reservoirs, not just Bay Area. That just happens to be an article for the Bay Area.

For instance, I live in Santa Barbara and all of our local reservoirs have human contact bans.

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