Erosion and Water Quality

Erosion is a vital issue for the Las Vegas Wash. Water quality is a vital issue for the entire valley. How do these two come together?

Las Vegas Bay, September 2000. See a larger photo

The Wash is the sole drainage channel for the entire Las Vegas Valley. Because of this, flows in the Wash have increased dramatically over the years. As the flows have increased, so have TSS (Total Suspended Solids). As flows make their way through the Wash, erosion starts to take place. When a storm event occurs, the fast flows grab the eroded sediment and carry them down the Wash (as seen in this photo).

The Connection: The Wash drains into Las Vegas Bay. Sediment is picked up along the way and deposited into Las Vegas Bay of Lake Mead. Total Suspended Solids are a combination of inorganic and organic materials; however, the majority are inorganic (approximately 90%), meaning the TSS are mostly stream bed erosion (sediment) versus vegetation (organic). Total Suspended Solids are one of the parameters monitored through water quality sampling.

Another consideration in the water quality equation involves lake levels. As Lake Mead water levels fluctuate, effects of sediment entering the bay also fluctuate. The Colorado River system is used by seven states. Because of this, in a dry year (and in accord with federal regulations), the lake levels are more likely to decrease because these states all have set water allotments they are entitled to by law.

Learn more about erosion control efforts.