How Fast Are California Reservoirs Filling Up?

Posted In: Water

In my previous post, about California water levels, I presented a “bar graph” showing the amount of water currently in California’s reservoirs.  However, I thought it’d be interesting to see how this has changed over the course of the last few months, since the state has gotten alot of rain and snow recently.  I decided to try and “animate” the graph for the current water year (going back to October 1, 2015) showing how the recent El Nino rain has been filling up the reservoirs in California.  Click the “animate” button below the figure and you can use the slider to change the speed of animation as it cycles through the days.  

You can really see a few interesting things:

  • how low the water level is in December
  • the start of the rains in January, which start to raise the water level
  • the March precipitation which makes the storage level rise very quickly



Notes: This graph is updated daily and is made in javascript from data gathered from the California Department of Water Resources website.











6 Responses to How Fast Are California Reservoirs Filling Up?

  1. Chani says:

    Thank you for putting this together! Wonder if a quick status can be developed from this data to drive conservation: green, amber or red. Would link a zip code to its water supply source, and calculate status for that zip code based on current water level, plus estimated inflow and outflow over the following 12 months.

  2. Brooke Robbins says:

    This is by far the best representation of CA’s water resources available. A really useful effort and greatly appreciated.

  3. Cheery says:

    Great graph!

  4. Richard kunz says:

    Realistically how close to 100% capacity will the water managers allow the reservoirs to get to. ???

    • chris says:

      Probably not that close. Given what’s happening at Oroville, it makes sense to keep a little bit of buffer (unfilled capacity) in the system to prevent any big storms from creating emergencies.

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