How Are Waves Formed in Lakes?

Can you imagine a world without surfing, Sea-Doo jet skis, or wakeboarding? We certainly can’t! But how are waves actually made? In the ocean, wind and gravitational forces make the familiar ripples in the water, but on Lake Travis, things are a little different. Here’s a complete overview of how waves are made in lakes.

How are waves created in lakes and on Lake Travis?

Waves are formed by energy moving through water. What causes that energy? On a lake, that depends. There are three main things that form waves in lakes: wind, seiches, and boat wakes.

Wind

Most waves on lakes are formed by wind blowing across the surface of the water. These waves, known as capillary waves, are generally small and disappear quickly – you’re not going to be able to ride one on your wakeboard! However, certain circumstances can turn a little ripple into a large swell:

• Wind speed and duration. Fast, consistent winds transmit more energy to the water, which means the waves they create are larger and last for longer. The longer winds gust across open water, the larger the waves will be.
• Fetch. The term “fetch” refers to the surface area of the water. Bigger fetches result in bigger waves. Because Lake Travis is relatively narrow, it has a pretty small fetch.
• Water depth. Waves like deep water, becoming faster and larger the deeper the body of water is. So, you’re more likely to see large waves on Lake Travis out by Hudson Bend, where the water is 210 feet deep.

Simply put, the more factors a wind wave has to feed it – speed, duration, fetch, and depth – the larger it will be.

Pressure changes

A dramatic change in atmospheric pressure disturbance – like a storm surge or seismic activity – can create a standing wave called a seiche. Seiches can only form on stratified lakes, where the water at the bottom of the lake reaches such a low temperature that it stops mixing with the warmer water at the surface. Lake Travis is usually stratified from April to November, making it a candidate for seiches during heavy storms.

When a seiche is made, the water falling from cresting surface waves becomes so powerful that the energy goes underwater and creates a standing wave below the surface. Seiches are typically not visible to the naked eye, but they cause the water in a lake’s basin to slosh back and forth, rapidly fluctuating water levels. Seiches can last anywhere from a few minutes to a few hours.

Boat wakes

Finally, waves can be created by boats traveling through the water, known as wakes. Boats create two wakes: a bow wake and a stern wake. All boats create wakes as they transfer the energy of their movement into the water, but boats need to be going at higher speeds to generate waves large enough for wake surfing, wakeboarding, or water skiing. 

While boat wakes are fine in certain parts of Lake Travis, keep your eyes out for “no wake” zones. If you zip past swimmers or smaller boats with a powerful wake, you can create dangerous water conditions, and making wakes too close to the shoreline can disturb local wildlife and contribute to shore erosion. You’ll typically find no wake zones near marinas, designated swimming areas, and narrow channels.

A word of caution: rip currents

Rip currents are not technically considered waves, but they are frequently associated with wave activity and pose a significant danger to swimmers. Rip currents generally form near jetties, piers, and sandy beach areas.

A myriad of factors have to come together to create a rip current. The current starts when waves rolling into shore create an underwater sandbar. This sandbar traps water, and pressure builds up. As the waves continue to push past the sandbar, eventually a portion of the sandbar collapses, forcing the trapped water back out into the lake. This rush of water causes a strong undercurrent: a rip current. 

A rip current’s rapid water dispersion creates a horizontal motion that can pull unsuspecting boaters away from the shore or sweep a swimmer off their feet. If you encounter a rip current, don’t fight it. Just remain calm – the current will just pull you away from shore unless you try to swim against it. Float or tread water until you are ready to swim out. To escape the rip current, swim parallel to the shoreline. Once you’re out of the rip current, you can head back to shore.

Ride the waves of Lake Travis at Northshore Marina

Are you ready to stop reading and start boating? Northshore Marina at the Hollows is your gateway to Lake Travis. Our floating, deep-water Lake Travis boat slips are specially designed to keep your boat safe (and accessible) as the lake’s water levels fluctuate, whether due to water releases from Mansfield Dam or underwater seiches.

We offer a seamless, VIP-level experience for our members – so good that it’s earned us the Marina Association of Texas’s “Outstanding Marina of the Year” award six times. From our luxury common area to our exclusive events, Northshore Marina will make sure that you have a premium experience.

Contact us today to learn more about how you can join Northshore Marina’s lively community of Lake Travis boaters.