Green-Up highlights importance of Las Vegas Wash

The Las Vegas Wash Green-Up event held March 12 helped underscore the important role the wash plays in the Southern Nevada watershed, and its critical function as a filter for water flowing into Lake Mead.

During the Green-Up, approximately 200 volunteers planted about 1,200, trees and shrubs on a four and a half acre site near the Calico Ridge Weir. These plants in time will take root and help stabilize the sandy soil in the wash, reducing erosion, improving water quality, and providing habitat for wildlife living in and around the wash. The event originally was slated for March 5 but was rescheduled due to inclement weather.

A 12-mile channel in the southeastern part of the valley that acts as the final link in our watershed, the wash funnels urban runoff, stormwater, shallow groundwater flows, and water from the valley’s three wastewater reclamation facilities back to Lake Mead. On average, more than 150 million gallons flows through the wash each day.

Among those contaminants are common fertilizers residents in the community use on their landscaping, many of which have been washed away with recent rains. SNWA Regional Water Quality Control Supervisor Peggy Roefer said that while no firm statistics are available on the amount of fertilizers flowing to the wash, and that they pose no threat to the wetlands, she suggested that community residents can take steps to limit their flow into the Wash and Lake Mead.

"We suggest you don’t overfertilize, as any excess fertilizer will be washed away if you are using more than the plants can uptake," Peggy said. She credited the various erosion control structures in the wash, called weirs, with slowing flows that enable sediments, fertilizers and other chemicals to fall-out before they can reach Lake Mead.

During the past five years, volunteers from throughout the valley have helped plant more than 17,000 shrubs and trees. In total, the Project Team in partnership with the community has enhanced the wash with 60 acres of native vegetation. Volunteers have also pitched in at the Wash Clean-Up, removing more than half a million pounds of trash from the environmentally sensitive area.