Lake Mead Monitoring

The source of nearly 90 percent of Southern Nevada's water, Lake Mead is under constant scrutiny by a number of limnoligists. These specialists study what organisms are present in the water so that the best water treatment decisions can be made.

Organisms living in the raw water source can contribute to taste and odor problems in the finished drinking water. These organisms also can clog the SNWA's water treatment filters.

Testing the lake

Samples are drawn from the lake every week to run tests which determine the presence or level of:

• Dissolved oxygen, pH level, conductivity, temperature and turbidity
• Nutrients
• Fecal coliforms and E. Coli
• Perchlorate

Thermal Stratification

Throughout the year, Las Vegas Valley Water District (LVVWD) personnel closely monitor the lake for the possibility of destratification.

During warmer months, the lake's top portion of water heats up faster than the deeper portions, causing a distinct layering of water, or thermal stratification. Separating warm and cold water, thermal stratification protects the deeper layer of water by forming a natural barrier that keeps organisms and pollution near the surface. Located at the same depth as the intakes, the deeper layer of water also is of better quality.

When the lake cools down in the winter, destratification can occur—that's the break down of these layers as the water becomes isothermic, or one temperature throughout. This can increase the possibility of pollutants traveling near the intakes. Throughout the seasons, a close eye is kept on the lake and its water quality as the population and water needs of Southern Nevada continue to grow.