Tributary Water Quality

Monson Drain, one of the tributaries leading from the Las Vegas Valley into the Las Vegas Wash.

Tributaries to the Las Vegas Wash carry water from urban and industrial areas of the Las Vegas Valley. The purpose of the tributary monitoring program is to characterize the water that flows from the tributaries into the Las Vegas Wash.

Sampling Sites
The seven major tributaries are: Meadows Detention (LVC_2), Las Vegas Creek (LW12.1), Flamingo Wash (FW_0), Sloan Channel (SC_1), Monson Channel (MC_2) and Duck Creek (DC_1) and Burns Street (BS_1). All of the sites are shown on this map.

Measuring the flow rate in a tributary

Sampling Frequency and Parameters
Tributary water quality monitoring is conducted on a quarterly schedule and occasionally during rain events. Flow measurements, water temperature, dissolved oxygen, pH and electrical conductivity are measured in the field.  Samples are colected and sent to be analyzed for heavy metals, cation-anion, perchlorate, nutrients, bacteria, and organic contaminants.

Results - Example
The study has been conducted for several years now and a significant amount of data has been collected. The chart below shows average Total Dissolved Solids (TDS) concentrations at the tributary and seep sites.

Average TDS concentration for tributary sample locations from January 2003 through December 2007.  LWC3.7 and LWC6.3 are no longer sampled.