AMNA NAWAZ: We turn now to the water crisis gripping North America's biggest city.

The Mexico City area is home to some 22 million people, and solutions to keep water accessible have been elusive.

As special correspondent Julia Galiano-Rios reports, there are a number of factors complicating the situation.

JULIA GALIANO-RIOS: This has become a daily routine for 53-year-old Teresa Vazquez.

To clean the dishes or wash clothes for her family of 10, she ladles murky water from a barrel.

It's been 10 years since a single drop came from her taps.

TERESA VAZQUEZ, Iztapalapa Resident (through translator): It's very hard living without running water.

We have to wash our clothes with very little water, do dishes with very little, shower with very little.

It's very hard to live without the water we need.

JULIA GALIANO-RIOS: Vazquez lives in the largely impoverished Mexico City neighborhood of Iztapalapa.

Every day, she has to buy bottled water for drinking and bathing her grandkids.

This water, she says, is too dirty.

TERESA VAZQUEZ (through translator): The water is not clean, but we need it, so we have to take it how it comes.

There's no point in complaining.

In fact, when we do complain, they sometimes don't even bring it.

So, yes, it's dirty, but at least we have water.

JULIA GALIANO-RIOS: Once a week, a city truck delivers water piped into an 800-gallon tank outside her home.

This is the reality for hundreds of thousands of residents in a sprawling metropolis running out of water.

Residents in this community, one of many like it in the city, tell us they rely on these trucks for their water consumption.

Now, as the situation worsens and the system becomes more and more strained, tensions rise in these communities, as neighbors vie for what little water there is available.

That means every trip for drivers like Cristian Ovando comes with risks, from navigating narrow, bumpy alleyways to violence.

CRISTIAN OVANDO, Water Truck Driver (through translator): We get sent to an address to deliver the water, but, sometimes, on the way, desperate residents jump on the truck and divert it to another location, and basically demand we give them water instead.

If we refuse, they can verbally and sometimes physically attack us.

JULIA GALIANO-RIOS: Mexico City has faced water shortages for years, but never like this.

Most, if not all of its key reservoirs, are less than a third full.

Some media reports, based on statements from the country's water commission, warn, Mexico City was nearing a day zero, when it can't provide any water to its people.

Experts say that's unlikely, but the situation remains dire.

The crisis has been exacerbated by climate change, hotter, drier conditions and lower-than-normal rainfall.

But there's a more immediate problem.

TAMARA LUENGO, Founder, Aqueducto: This water crisis is not a crisis of water resources, but, rather, a crisis of management of resources.

JULIA GALIANO-RIOS: Tamara Luengo, a self-proclaimed water nerd, runs an environmental consulting firm in Mexico City.

Luengo says the mismanagement started centuries ago, when Spanish conquistadors drained the region of water to build a city on lake beds.

TAMARA LUENGO: This city continues to be rich in water, of course.

The mismanagement of the water in this city has caused that this wonderful water city is not visible at the moment.

JULIA GALIANO-RIOS: Today, Mexico City draws about 30 percent of its water from the Cutzamala System, a collection of reservoirs, pipes and plants over 75 miles away.

The rest comes mostly from underground aquifers, tapped by hundreds of wells.

But the network that brings water to residents is in bad shape.

About 40 percent of the city's water is lost in leaks.

Even though Mexico City gets about 30 inches of rain a year and frequent flooding, its ability to hold on to that water is practically nonexistent.

The city also rarely uses practices like wastewater treatment.

TAMARA LUENGO: Fixing a network so old as the network of Mexico City requires a series of resources, such as will, for starters, to fix all the network and to avoid this 40 percent being lost.

JULIA GALIANO-RIOS: Newly elected president Claudia Sheinbaum, the former mayor of Mexico City, defended her record on this issue on the campaign trail.

CLAUDIA SHEINBAUM, Mexican President-Elect (through translator): As mayor, we did carry out works and we do have projects which we will carry out in the greater Mexican City area when we reach the presidency, so that we can have water supply in the long term.

So, yes, we did things, and we do have projects.

JULIA GALIANO-RIOS: Luengo says part of the reason the crisis has received so much attention is because of who it's affecting.

TAMARA LUENGO: Throughout the years, the vulnerable communities of the city in the poorer areas of the city, within marginalized communities were the ones facing the water crisis.

But, strangely, within this water crisis, we have been seeing that some of the richer areas of the city are facing this day-by-day, continuous evidence of the water crisis.

And this definitely has brought a lot of attention.

JULIA GALIANO-RIOS: In Iztapalapa, Teresa Vazquez and her family feel the inequality firsthand.

Vazquez's daughter Brenda hopes politicians just fulfill their promises this time around.

BRENDA ESCALANTE, Iztapalapa Resident (through translator): All that money that politicians spend on putting up banners, TV ads and all that, the fair thing would be for them to spend it on these neighborhoods, so that we can have water, so that we can be a bit more comfortable and experience what other neighborhoods do, which is opening their tap and getting their water and being able to wash their dishes or take a shower.

JULIA GALIANO-RIOS: A basic need that more and more residents can no longer take for granted.

For the "PBS NewsHour," I'm Julia Galiano-Rios in Mexico City.