Lake Mead: The devastating impact of a 22-year drought on America's largest reservoir as water levels fall to record low

ITV News US Correspondent Emma Murphy is with the south Nevada Water police cracking down on residents wasting water

Nature has a way of telling its story in a more powerful way than any words.

The watermark around Lake Mead is a graphic illustration of just how much has changed in America’s largest reservoir.

Huge white bands, as high as 10 double decker buses, mark its craggy sides.

The white line marks what should be the water line. Credit: ITV News

The 50-metre ring line shows where the water level was and how far it has fallen.

The reservoir is at just 35% capacity, the historic Hoover Dam it powers is producing 25% less output, and scorching summer temperatures are nudging the mercury to record levels.

But don’t call this a crisis to those managing water and power in Nevada.

It’s a concern, yes, but apparently not a catastrophe in the making. Talk of Hoover Dam being rendered obsolete within eight years is dismissed as folly.

The historic Hoover Dam it powers is producing 25% less output.

However, things are changing in America’s West as a two decade mega-drought and environmental change are compounded by temperatures which are extreme even for this part of the world.

It was 43 Celsius (111 Fahrenheit) in Las Vegas at the weekend.

As a result the authorities are on the verge of declaring a historic water shortage in the Colorado Basin.

The reservoir is at historically low levels. Credit: ITV News

That means the water supply will be reduced in Nevada, California and Arizona. Because Arizona has more farmland it is likely to take a cut of up to 18%.

Twenty five million people rely on Lake Mead for water, eight million take power from the Hoover Dam.

Strikingly, the drain is not so much from the excess of Las Vegas’ strip which conserves and recycles most of the water it needs, but agriculture and the local community.

The pressure is now on farmers to find different ways to irrigate and residents to be water-wise.

While the local and federal government manage the big picture, locals are being urged to do their bit.

Twenty five million people rely on Lake Mead for water.

Across Las Vegas, day and night, water waste investigators are busy at work.

Their job is to find those flouting water laws, to educate them, and if that fails, to force change through fines.

It might sound like a small part of a big problem, but in a few hours on the road with them you realise how much water is wasted.

Whether it’s a sprinkler spewing water across the street or a broken faucet pumping water down the drain, it’s all water that is disappearing from a system under strain.

'Every drop counts'. Credit: ITV News

Their motto is every drop counts and it’s increasingly clear it does - especially when those drops run into millions of gallons.

Every system has its breaking point but those managing this one believe they have appropriate checks and balances in place to protect those who rely on it despite the environment serving a curve ball that came faster than they expected.

The reality is everyone is going to have to do more with less - whether on the Strip, in the water hungry fields or in homes across the region.

The message is very clear, everyone’s world needs everyone’s help and the responsibility is not someone else’s.

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