Good afternoon.

Welcome to the October 17, 2024 meeting of the Sacrament Area Flood Control Agency Board of Directors.

Would the clerk please call the roll?

Thank you.

Director Desmond.

Director Frost here.

Director Hume.

Here.

Chairman Kennedy.

Here.

Director Cerna.

Director Jennings.

Here.

Director Kaplan.

Director Talamintes.

Director Holloway.

Present.

Director Johns.

Director Abdes.

I am here.

Thank you.

Director Perez.

Present.

And Director Conan.

We do have a 10 member quorum.

Thank you very much.

Is there any um members of the public that would like that are signed up?

I have not received any requests.

There are any members in the audience.

Seeing none, we'll go to separate matters.

It's not on the agenda.

I do what she tells us.

It's on my agenda.

Let's do the pledge.

I pledge allegiance to flag the United States of America.

And to Republican for which it stands one nation under God indivisible with liberty justice for all.

Thank you all for your patriotism.

Our first item is separate matters and information item on the history of the Sacramento level of flood protection.

Good afternoon, members of the board.

Rick Johnson, executive director.

So at the last board meeting, we had a member of the public indicate that needed more information about the level of protection and its history for Sacramento.

So I put it right up in the written thing.

So, real quickly, back in the mid-50s when the Corps finished building Folsom Dam, about that same time they finished the work on the levees.

And back in those days, they would for urban areas they would design systems to handle a standard project flood.

And um they didn't assign a frequency to those, but volume-wise, it was about the same size as a 500-year event.

So originally we had about a 500 year level of protection.

Now over the years we we learned we didn't really have that.

This graph, I know I've shown it to you before, but its peak flows on the American River, the red line is when Folsom Dam construction was started.

If you look at what's left of that red line, that's the record they used to design the system based on.

And you can see what happened right of that red line.

In fact, after Folsom Dam was completed, we had five record storm events in 46 years.

And so after the 86 event, the core downgraded um the level of protection to about 60 years, and then after the new urban levy standards came out after Hurricane Katrina, some parts were down as low as 30 years, like the the Natomas area.

So we a lot less than we originally thought we had.

And they looked at the American River.

One of the things they did in there was a tree ring study.

They recreated the American River flows back to 1560.

And what they found is the period from 1950 to 1917 to 1950, which is the period right before that they used to design the system on was the most extreme dry period in 420 years.

And in fact, they recommended that the Corps drop that period out when they calculate the frequencies.

And then in addition to the more frequent larger events, uh 2020 America River Basin study showed that the timing of the runoff is coming earlier in the season.

And so graphically, what that means here is runoff that used to come in the spring and um early summer would now um come back into the fall and rent winter, and so I laid on top of that our flood control diagram at Folsom where Folsom is a multi purpose, so in the winter time flood season, we draw it down 40 to 60 percent.