City Cast Las Vegas logo

What You Should Know About Las Vegas Storm Drains

Posted on September 6, 2023   |   Updated on September 30, 2025
Scott Dickensheets

Scott Dickensheets

Photo of water gurgling down a storm drain.

Storm water makes its way to Lake Mead — untreated. (kerkla/Getty)

In light of this weekend’s heavy rainfall, here are a few words about the valley’s storm drain system.

Two Ways to the Lake

Las Vegas has two systems for disposing of excess water. The sewage system carries sink and toilet water to a treatment plant, where it’s processed before being sent to Lake Mead. Rain and runoff water travels through storm drains and channels directly to the Las Vegas Wash and on to the lake.

Which Means …

Runoff water isn’t treated before it’s dumped back into our main source of drinking water. Therefore, flood control officials say, “The largest source of stormwater pollution in Las Vegas Valley results from everyday activities.” That is, pet waste, pool chemicals, automotive drippings, pesticides, and more. “One quart of motor oil can contaminate over 250,000 gallons of water.” Most of us don’t pour a quart of motor oil into the gutter, of course. On the other hand, oil from driveway leaks gets carried off by rain, and adds up. Tips for preventing your share of that pollution.

History

Despite the footage of rampaging floodwaters in Las Vegas during the past weekend’s storms, Las Vegas is generally well-protected from flooding — the result of $2 billion in flood-control infrastructure installed by the Regional Flood control District over the last 30 years: some 100 water retention basins and more than 600 miles of flood channels.

People

There are, notoriously, people living in the valley’s extensive storm tunnel system — about 1,500 of them, according to Shine a Light, a nonprofit that helps such people transition out of the tunnels. (And sometimes helps rescue them after torrential rains.) There’s even been a book about them, as well as a sequel.

Share article

Hey Las Vegas

Stay connected to City Cast Las Vegas and get ready to join the local conversation.

Can't subscribe? Turn off your ad blocker and try again.

The latest in Las Vegas

Keep It LocalSeptember 17

Your Guide to Las Vegas Butcher Shops

Explore Las Vegas' best butcher counters, from whole-animal butchery at Featherblade to Diamond Spur's ranch beef. Find dry-aged ribeye,...

A close up of a cheeseburger in a wrapper, showing the melted cheese, lettuce, tomatoes, pickles and meat.
Keep It LocalSeptember 17

Know Thy Meat: A Buying Guide with Chef Brad Wise

Master the meat counter with 5 expert tips from Brad Wise of Wise Ox. Plus, get a sneak peek at their new Las Vegas location and 2027 Ox...

A glass case showing cuts of meat.
Food & DrinkSeptember 14

5 Reasons for Locals to Brave the Strip This Week

This week is busy with culinary pop-ups, festival events, and a few discounts that even locals could love on the Strip.

A dining table filled with plates. A close-up shows a tartine with rolled slices of meat.
Keep It LocalSeptember 10

The Vegas Entrepreneur Giving Fan Gear a Makeover

From a Vegas hair agency to major sports licensing deals, discover how Whitney Bansin’s viral gold sequin jackets launched her fashion br...

A couple poses in Raiders jackets.
Keep It LocalSeptember 10

Four Ways to Up Your Sports Game

Discover local businesses that have everything you need to dress the part, find vintage gems, and show love for your favorite team. Dive...

4 Raiders baseball caps sit on a desert ground.
Food & DrinkSeptember 9

The Border Grill Banks on a Big Future

Susan Feniger and Mary Sue Milliken prove long-term success is possible on the Strip with a renovation and lease extension at the Border...

Susan Feniger and Mary Sue Milliken sit at a wooden table with four plates of different Mexican dishes.
Food & DrinkSeptember 8

Mama’s Finds a Home for Vietnamese Cooking in Las Vegas

Durango Social Club enters a new phase with a permanent residency. Enjoy traditional, refined Vietnamese homestyle cooking from Executive...

A plate of Vietnamese food.
Las Vegas' BestSeptember 2

City Cast Las Vegas Repeats as 'Best Vegas Podcast' in Las Vegas Weekly’s Best of Vegas Awards

For the second year in a row, City Cast Las Vegas was named "Best Vegas Podcast" by Las Vegas Weekly readers.

City Cast staff accept an award.