Hello and thanks for joining us for sustaining us a brand new series here on KLCSPBS.

I'm David Nazar.

Throughout the year we're going to bring you informative and educational field reports and expert guests to discuss vital environmental and economic sustainability issues everything from climate change clean air water technology and health care to education pandemics and housing.

We begin our broadcast with California and rain as odd as this sounds given decades of drought is California on the brink of a massive flood of biblical proportions a phenomenon so great some scientists say this could be the costliest natural disaster in world history Earthquakes wildfires mudslides.

Mother Nature can be a mad scientist when she wants to unleash her fury on California.

For decades the Golden State has been badly these natural disasters.

Well these days you can possibly add one more looming natural disaster.

Many climate scientists who study extreme weather say California could expect a statewide flood of almost Noah's Ark.

Biblical proportion.

Daniel Swain studies extreme weather events like droughts floods and storms.

Swain is a climate scientist at the Institute of Environment and Sustainability at UCLA and has just published a special report on climate change and its relation to California flooding.

We definitely have seen more of a water deficit than an over abundance recently.

But In the long run there is actually a history of very significant floods in California.

If you go back over decades there are certain parts of the state small regions of the state that have experienced serious or even devastating floods.

The Great Flood of 1862.

Is really the flood of reckoning in California.

So it was a dramatically different world back then when this flood came and essentially turned the Central Valley into an inland sea and inundated places in the San Francisco Bay area.

And in Los Angeles County and Orange County the great flood of 1862 began with heavier than normal rainfall and snowfall which turned into a deluge of rain of narrow bands of dense rapidly traveling water vapour called atmospheric rivers filled the sky about a mile above sea level.

These rivers in the sky were able to transport 15 times more water vapor than the amount of liquid water that flows from the Mississippi River into the Gulf of Mexico.

Atmospheric rivers have been a few times every year and when they occur over days flood risk increases.

That's part of the reason scientists are now concerned that California could be due for another catastrophic flood as the climate warms.

This This risk of flooding in the coming decades is likely to increase pretty dramatically relative to what it has been historically.

There is something like a 50 percent chance that this event could happen between now and 2060.

So essentially a 1 in 2 chance of this event occurring in the next 40 years or so.

How serious is flooding going to be in the Central Valley for example.

That might include inundating an area all the way from the southern San McKean Valley into the Northern Sacramento Valley.

And that would include cities like Fresno and Sacramento and Modesto and Stockton and would inundate a significant portion of the bay shore regions in the San Francisco Bay Area.

This sort of storm would also be associated with strong winds which would actually cause a certain sort of storm surge.

So this flow of water into the bay from the ocean combined with the flood waters from the rainfall potentially inundate parts of Silicon Valley.

And if you go down to southern California.

Large parts of L.A. County that lie in natural flood plains would probably also be inundated.

It's possible that the L.A. River flood channels would be seriously challenged by a flood of this magnitude Orange County San Diego County.

A similar story.

Millions of people now live in places that the last time this happened were under water.

The total economic damages both the direct losses plus the indirect economic losses they were as a result of of of loss businesses and economic activity in the wake of the event.

Would be essentially a trillion dollar disaster should this recur.

And that would make it the most expensive natural disaster in the history of the world.

It depends on how hysterical you want to get to really push public policy based on theories and nothing proven is kind of difficult for me.

Brit Barbara has worked in the water industry for over 20 years.

Barbara is a board member of the Metropolitan Water District of Southern California the largest water agency in the world and he is also a board member of the municipal water district of Orange County.

We met Barbara out here at the Santa Ana River which helps control storm runoff the Santa Ana River runs from the center or Tonio mountains through Riverside County on into Orange County and then out to the Pacific Ocean.

Barbara a staunch conservative says he's concerned that climate scientists are scaremongering when talking about a repeat of the great flood because of climate change.

For them to make these pronouncements where things definitely you're going to be one hundred years from now.

We don't know that we can't figure these things out and scientists are very smart and they look at lots of numbers but if they're off just a little bit in one level like you've seen it throws off all the models down the road.

So I trust the farmers to figure these things out because they understand how nature works they understand how their fields need to be planted how they need to fallow those they don't need some bureaucrat in Sacramento or DC telling them what to do.

So I tend to side with the farmers who are actually there working in the soil and they're more weather dependent than scientists are.

You side with the more Absolutely.

Absolutely.

Why is that.

Because they're more practical.

They have a hands on experience.

It's one thing to live in an ivory tower working on your models and that's great and that's fun to do and it's good to debate that.

But when you have to put it into reality and put it into action that's very different.

To be clear are you Discounting or possibly even disputing some of the science that these climate scientists gather regarding the flood or climate change.

Look we are gonna have floods in the future.

To put it all on climate change I think it's ridiculous.

Nature has a way of working in cycles.

We're in a little warmer cycle now it'll go back as a public policy person.

You look at risk.

You look at the science you look what's out there and to really base all of your decisions based on what might happen.

Percent may happen in the future.

I think it's folly.

The critical question becomes what level of protection are we willing to pay for.

So flood protection.

Comes at a cost.

Benjamin Preston is the director of infrastructure resilience and environmental policy at the RAND Corporation.

This climate scientist studies climate risk management.

He says dealing with catastrophic weather events can be a challenge to find the best solution.

We have to figure out How much are we willing to pay in order to completely mitigate or climate proof Southern California Los Angeles from a future flood event.

And so we have to balance risk on one hand with cost effective solutions.

And in so doing inherently we're gonna run into tradeoffs so we don't want to spend.

Two dollars to avoid one dollar in damages.

So trying to understand what is a reasonable level of protection and what science society is willing to accept in terms of risk is critically important and the science can inform that.

But ultimately that's a matter of public policy.

And public deliberation.

So when it comes to flood risk.

Effectively the default standard level of protection that we're used to and have accepted is a one in 100 year event.

Or a 1 percent chance of a.

Particular flood level in a given year.

But the other standards out there and it comes down to an understanding of cost.

And how much we're willing to pay man in nature can coexist in many ways.

And we've done a tremendous job in figuring out how to overcome that our modern recurrence of this event would be an economically devastating event for California should it recur in the near future.

Joining me now to discuss this further is David Kogan.

David is with the UCLA Institute of Environment and Sustainability.

He's also an author and teaches science communications.

Thanks for being here David.

Thank you David.

Two polar opposites in this field report.

You've got the scientists and you've got the water expert the water expert is saying you folks the scientists live in an ivory tower.

What is What is your take on that.

You know I think he relies a lot on sort of linguistic tropes that aren't really accurate in this situation.

A couple of things that really tipped me off to that while I was listening to him talking where his confusion of the term theory right now he uses theory in the colloquial sense which we you know we understand is a hunch or a suspicion right more than what it means in the scientific sense which is something that's been proven time and time again through you know observation tests and relying on facts over a long period of time.

And so I think that's either unintentional misinformation or possibly even intentional obfuscation of the issue.

However you use the word facts he says he bases his facts not on science or the scientists he listens to the farmers.

DAVID Sure.

I mean that's pretty anecdotal as far as I'm concerned.

And I'm not sure which farmers he's talking to in this case you know across California I think there's this and the war and across the country there's a sort of understanding of the sort of single family farmer who sort of tells their own land and like is just like a good of the earth person.

But I mean the reality in California is most of this land that's getting farmed is big agri business it's you know it's big companies that are distributing around the country and around the world.

So if he's listening to them yet they may also be filling his campaign coffers when we listen to this story.

It's a sort of example David of what's happening United States the divide.

We've got this scientists we've got I don't have you call Bret Barbara a science denier or he just I don't know if he believes everything that the scientists are saying.

What is your take on the divide that we're having in the United States over climate change global warming and the climate science I mean I think my personal take it means complex is a lot of moving parts here but this all starts with some intentional disinformation coming out of the oil industry and the fossil fuel industry where you know they saw what happened and how quickly the aerosol industry was turned on its head after the ozone hole became a big thing in the news and they were much readier with their information campaign and have intentionally cast doubt on science.

You hear that through the voices of people like Brett Barbary.

If you hear that through the voices of people all around the country and it's just not fact based information it's it's talking points and they have an agenda.

Yet some of the voices in the United States are saying hey we get there is climate change we're get this global warming but we're worried about our job or worried about the education of our kids.

We're worried about paying the rent folks believe in climate science.

I believe it just doesn't seem it's a priority.

DAVID Yeah.

I think there's a real issue with and this is completely understandable that people are focused on their daily lives and what they need to do to survive and thrive and help their families be successful in the world.

That's 100 percent understandable.

And that's all stuff that needs to be part of whatever solutions we come up with the climate change you know it has to include jobs it has to include education about the world and about the science that describes the world.

And I mean we're not there yet.

So it's not something that can be separated out in my in my mind.

The idea that we treat the environment right as some discrete issue instead of the entire world and existence that we all depend upon for all of those things that you mentioned is a real I think.

I think that's a real bit of misdirection.

Yet some of this could be based on the fact that scientists even your scientists at UCLA possibly just don't get the message out there right the science messaging is not there because it seems that folks don't or some folks don't believe what the science has to say.

Yeah I mean I think that's partly my job as a science communicator.

And it's certainly something that we see is that that you know scientists who are really in the day to day basis sort of acquainted with the facts and are really deep in the information have trouble perceiving what the common perception is as a fact in question.

Right.

They need to understand that these perspectives they may not be valid to them because they're so deep in the data but they exist in the world and they have to be dealt with in a respectful way I think.

And so I think the more scientists can treat those perspectives not in a sort of condescending way but in a way that meets them where they are and tries to and tries not to demonize those sort of misperceptions the better off we'll all be.

You use the word condescending and it takes me back to a quote in the field report I put together where Brad Barbieri said basically quote This is folly meaning this is nonsense and that's condescending to many people probably you included and your scientists.

Yeah.

There were a couple things I found a little bit Yeah.

certainly condescending.

The idea that these findings of actual scientific papers that are peer reviewed are quote pronouncements of what will happen in 100 years is completely misdirection as well in my opinion.

I'm not even really in my opinion that it's just straight up misdirection.

I mean these are they're certainly doing projections of what may happen in 100 years or what they anticipate will happen based on the facts their observations and a whole lot of information.

But we're not saying yes this will certainly happen in 100 years right we're just projecting this is the best be we know based on the information we have available to us yet you realize and you have to know this when some people hear that scientists are saying there's going to be a great flood of biblical proportions which is going to demolish California and all kinds of catastrophic damage.

People are going to be like well that's crazy.

And where do scientists get this data.

So in defense of red Barbara and I'm not defending him because we all have to believe in the science but maybe he's saying there's a more centrist approach where we might not be so extreme.

Yeah.

I mean I think though you know when we're back on things sort of our our economic goals with dealing with global impacts we need to be a little bit more realistic and a little bit more far sighted.

We're talking in this case it's about a flood that we have experienced right.

We have saw it in in the 18 60s right where you know the governor had to canoe from the second floor of his Sacramento home to be inaugurated and and the fact is is that this happened then it certainly can happen again.

And all the data that we are looking at shows that it then it may well be more likely now that climate is changing.

David Cole going to UCLA.

Thank you so much for being here.

Thank you for the interview.

Thank you David.

And now we traveled to the San Diego Mexico border region where rain flooding and the possible climate change connection are causing water pollution problems in our border waterway PBS station K PBS and San Diego visits with wild coast an international nonprofit environmental organization.

Reporter Eric Anderson has the story Wild coasts Paloma Geary stands just a few hundred yards north of the U.S. Mexico border.

She's in goat Kenya.

It's one of five places where sewage tainted water from Mexico flows freely into the United States.

It's catastrophic for anybody who doesn't know this area or about this issue.

It's very simple it's one of the biggest environmental disasters that our country suffers every single year.

And now with climate change.

Forecasting more intense storm events we're going to see this problem exacerbated over time.

Go Canyon is actually a success story of sorts.

Gary is standing beside two large catch basins that keep sediment from swamping wetlands in a nearby state park.

Whenever it rains it's it's a canyon.

It drains the lower.

Ellis creeks flows across the border And into this area.

There is a pollution collector nearby that routes tainted water flow to the International wastewater sewage treatment plant.

That facility was built to help treat cross-border flows during dry weather.

Meanwhile these catch basins keep sediment out of sensitive habitat.

Just a few hundred yards away one key feature is the small fence that reaches across this basin.

These These are the only types of trash booms in the entire Tijuana Reveille.

They're highly effective especially for a very high floater pools as you can see there's a lot of plastic bottles.

There's a lot of foam And that is because in Mexico in the state of Baja California and in the city of de Juana they don't have a formal recycling program.

What happens if this barrier is not here and these plastics and the tires and the sediment Reach the wetlands that are just over the hill.

I mean we had a case where there was a construction project into Quanah so they just cut the hillside there.

There was no plan for sediment control and all of that access sediment destroyed about I think it was between 30 and 40 acres of wetland and salt marsh.

Habitat.

So it's incredibly detrimental to the system.

And obviously plastic input into the ocean marine debris is one of the biggest challenges we will face in the next decade or two.

We have studies that overwhelmingly You know come to consensus that we'll have more plastics in the ocean than fish by 2050.

The catch basins and trash booms were put in place by state officials to protect sensitive habitat at Border Field State Park.

And Gary says there are lessons here for other locations in the two Hunter River Valley.

Just a short distance to the east.

Bridge Over Dairy Mart road separates a wide sweeping Valley and more rugged river habitat.

His sturdy concrete structure was built after flooding washed out the old bridge in the 1990s.

This is a point where the river forest or the riparian habitat begins.

So a lot of the trash and tires that are carried by the storm flows become trapped in the vegetation.

And whatever is not trapped makes its way downstream into the estuary and ultimately into the ocean.

On this side of the bridge the river valley is open but this bucolic stretch of land changes dramatically when rain drenched the region.

The small trickle of a river during dry times can become a raging torrent of swirling pollution.

When there is a strong storm event this can be completely covered in water and the river can be flying at a rate of a billion gallons of water per day most of which is completely sewage tainted and polluted.

Geary would like to see some of the lessons from goat Canyon applied here she says catch basins could capture wet weather as sewage flows sediment and trash.

She says the international wastewater plant on this side of the border and to want a sewage system frequently falls short.

There is a pump station right at the border that is capturing all that flow and sending it south from us preventing that flow from coming across the border.

The problem is that pump station breaks down all the time.

Because it gets clogged with sediment because it gets clogged with trash.

So some of those when that pump station fails and some of those flows could be captured by the sediment basin Geary says.

The tainted water that currently fouls the ocean and forces health officials to close South County beaches could be held until it's treated.

Federal officials say a lack of funding keeps them from building that infrastructure.

But local critics say there is a lack of will.

That's why Imperial Beach Chula Vista the Port of San Diego California and Surfrider San Diego are suing the federal government.

They hope the courts compel the International Boundary and Water Commission to stop the cross-border sewage flows that pollute U.S. waters.

Eric Anderson Cooper PBS News thank you Erica Anderson and Kaye PBS for that report.

Now to waterway problems in Arizona and the fight to preserve that state's rivers.

This next story is brought to you through a special collaboration with KOCO PBS and Arizona State University's Cronkite School of Journalism and Mass Communications as we partner with and mentor students seeking to explore the environment through their reporting.

Here is Madison station with Cronkite News.

It's a tale of two rivers one the Verde runs into the valley from Northern Arizona the other the San Pedro flows up into the state from Mexico.

Both rivers are at the center of lawsuits filed with the hope of protecting each of them.

The story of Arizona rivers is that we have demonstrated many times that we can drive them up.

But we.

Haven't Demonstrated that we can save them.

That's why in March the Center for Biological Diversity filed that intent to sue the U.S. Forest Service over cattle damage along the Verde River.

There's been multiple reports from the public and from us that the Forest Service that.

There is cows out on these protected rivers and the Forest Service just hasn't been doing enough To fix the problem and so we knew we had to take it to the next level.

The U.S. Forest Service said in a statement that the agency has some preventative management options to help like fencing and designating specific areas for cattle to access the water.

The Verde isn't the only Arizona river with livestock degradation in southern Arizona.

It's happening on the San Pedro River.

The Center for Biological Diversity and other partners like the Sierra Club filed litigation this spring to protect the San Pedro from livestock grazing.

The lawsuit against the Bureau of Land Management challenges with the Center reports as unregulated grazing and that's not the only lawsuit the two groups along with other partners also filed a lawsuit to protect the San Pedro from groundwater pumping.

Sandy Barr says this is one of the biggest threats facing the San Pedro sections up the river that were once perennial.

Meaning knife.

Flowed year round are are no longer.

Flowing year round.

The lawsuit is against the U.S. Army and the U.S.

Fish and Wildlife Service.

The regional director for the U.S.

Fish and Wildlife Service wrote in a statement that they are working with partners to reduce new well drilling and promote efficient water technologies on agricultural lands.

Both San Pedro lawsuits are in the earliest stages and that is the Dayton Cronkite News thanks Madison state and the Cronkite School of Journalism and Mass Communications for that report.

For more information about our program just click on us dot org and then click Contact us to send us your questions and comments or story ideas so we can hear from you.

Thank you so much for joining us for this edition of sustaining us here on KLC s PBS.

I'm David Huizar