Did you know that the Las Vegas Wash is more than just a ditch? The Las Vegas Wash below Lake Las Vegas near Boulder City is a vital channel. It carries excess water from the Las Vegas Valley into Lake Mead.
This 12-mile-long channel is sometimes called an urban river. The Las Vegas Wash exists today because of the city’s population. It works with the wetlands that once formed the Las Vegas Valley’s oasis. Urban runoff feeds the wash. Shallow ground water and stormwater also feed it. Reclaimed water contributes too.
Think of the wetlands as the kidneys of our environment. They clean the water flowing through them. The wetlands filter residues from fertilizers and oils. They also remove contaminants from roadways and the desert.
Near Las Vegas Bay, the Las Vegas Wash passes under Lake Las Vegas. It flows through two seven-foot pipes. Before development, the wash could handle rainwater. But when the first sewage plant opened, flows increased. The channel grew as the water eroded the stream banks.
This erosion deepened the channel. It drained one of the largest desert wetlands in the U.S. southwest. Water flowed down the channel instead of flooding the wetlands. This caused increased silt in Lake Mead. Fewer migratory birds visited. The native plants could not polish the water as well. Invasive plants like African Tamarisk and Sahara Mustard spread.
The major natural sources that feed the Las Vegas Wash are Duck Creek and Las Vegas Creek. Flamingo Wash, Pittman Wash, and Monson Channel also contribute. Sloan Channel, Meadows Detention Basin, and Tule Springs Wash add to the flow.
To manage the waterway, the Southern Nevada Water Authority is building aquatic speed bumps. These 61 million dollar projects will slow the flow and prevent erosion. When water rushes too quickly, it damages banks. It also deepens the channel and sends sediment into Lake Mead. This has negative environmental effects.
The Water Authority installed four low dams or weirs between 2002 and 2017. The newest project will add five more weirs along the last 3.5 miles of the wash. These weirs help protect wildlife habitats. They protect habitats from changing water levels.
Cottonwood, willow, and mesquite trees grow along the wash. Aquatic plants thrive here too. These create homes for birds, foxes, coyotes, and ringtails. The plants filter pollutants from upstream.
The Las Vegas Wash has come a long way. It is a testament to how we can adapt and protect our precious resources. The Las Vegas Wash below Lake Las Vegas near Boulder City protects and enhances the valley.