Water is a vital resource to the Mojave Desert. To understand its importance, one must first consider how it moves, its impact on the ecosystem, and how human influence can affect its journey. Watersheds are a key component of this understanding, making them an exciting and vital subject of study. So, what is a watershed, and how does it connect our students to the community and its outdoor spaces? Here are some basics of a watershed to answer these questions and provide information for a more impactful classroom lesson.

what is a watershed?

A watershed is an area of land that provides water to a specific waterbody. It sheds water from snowmelt or rainwater into streams and rivers. As gravity propels the water downward across mountains and valleys, these smaller water sources often connect to bigger ones such as lakes and even the ocean.

what makes a watershed?

There are many functioning parts of a watershed. A watershed begins at the highest peak of mountains and ridges, called the watershed divide. The main river or parent waterway is called the mainstem. Not all water from precipitation flows down into the mainstem. Water can take many different routes and can derive from many different sources. It can also store under the surface, this is known as groundwater. The underground area where groundwater accumulates and is stored is known as an aquifer. Groundwater and aquifers can also provide water to the mainstem or smaller adjacent streams. A tributary is a smaller stream that connects and provides water to the mainstem. Places where water is stored in or above the soil for all or most of the year are called wetlands. Wetlands are an essential part of a watershed, as the plants and sediment regulate floods and purify the water. Water stores within the plants surrounding a wetland or watershed boundary, and animals rely on the same freshwater for survival. Essentially, all living and nonliving things within the divide store or move water and are integral to a watershed system. A map of Nevada’s watershed can be found here.

There are three major aquifers in the Las Vegas Valley, about 300 to 1,500 feet below the surface. The water in these aquifers is protected from surface contamination by a thick layer of clay and fine-grained sediments, which act like filters, weeding out nearly all the contaminants.

Southern Nevada gets about 90% of its water from the Colorado River. (Las Vegas Valley Water District, n.d.-a). The Las Vegas Valley itself resides within a watershed that drains into Lake Mead, a man-made reservoir, and the Colorado River. Find out why The Colorado River is The Hardest Working River in the West.

the las vegas wash

The Las Vegas Wash, also known as the “urban” river, connects the Las Vegas Valley to Lake Mead. A wash helps carry water from higher to lower elevations, and the amount of water it retains fluctuates throughout the year. The Las Vegas Wash is about 12 mi. long and transports more than 200 million gallons of water every day. About 2% of Lake Mead’s water comes from the Las Vegas Wash.

Clark County Wetlands

The Las Vegas Wash, also known as the “urban” river, connects the Las Vegas Valley to Lake Mead. A wash helps carry water from higher to lower elevations, and the amount of water it retains fluctuates throughout the year. The Las Vegas Wash is about 12 mi. long and transports more than 200 million gallons of water every day. About 2% of Lake Mead’s water comes from the Las Vegas Wash.

The Las Vegas Wash, Lake Mead NRA

Flora & Fauna

The Wetlands are a place of refuge for migratory and resident animals. According to the records of the Wetlands, over 70 species of mammals, reptiles, amphibians, and over 310 species of birds reside within the park. A few of these animals include the great blue heron, the cottontail rabbit, the western whiptail lizard, and the coyote (photographed in order).

Great Blue Heron
Cottontail rabbit
Western whiptail lizard
Coyote

The Wetlands are also a haven for water-dependent plants, many of which wouldn’t survive in desert conditions. Goodding’s willow trees, common reeds, screwbean mesquite trees, and creosote bushes can be found in the park(photographed in order). These plants provide lush and vibrant greenery to the surrounding area and purify the water and air within the environment.

Goodding's willow trees
Common reeds
Screwbean Mesquite tree
Creosote bush

The entire Las Vegas Valley resides within a 1,600 square-mile watershed

why are watersheds important?

Animals, plants, and people rely on freshwater sources for survival, and watersheds ensure that water is cyclically replenished into those sources. The health of a watershed directly affects the health of all living things.

A watershed benefits plants, animals, and the ecosystem. It contributes to flood control and reduces erosion. Watersheds are also vital to climate control, preventing droughts and desertification.

what threatens a watershed?

Toxification of a watershed can affect the quality of a river’s fresh water, ultimately affecting the livelihood of all living things within the area. Nonpoint Source Pollution (NPS) is water pollution with many non-distinct origins, often from rainwater washing pollutants into bodies of water. Most nonpoint source pollutants are man-made, and improper disposal of these can poison the water and surrounding land. Common pollutants in urban areas are pet waste, household chemicals, oil from vehicles, and litter. Learn more about Nevada’s Nonpoint Source Pollution.

View of the Las Vegas Strip from the Clark County Wetlands Park

what is Nevada doing to protect watersheds?

Watershed management is a forward-thinking approach to controlling the quality and quantity of water within a watershed. Watershed management is a natural way to mitigate water resource issues and plan for environmental changes caused by climate imbalance and human impact. Actions are being taken to sustainably manage our state’s watersheds. The Nevada Department of Environmental Protection is developing watershed management plans to improve the management of the water in our community, ensuring better quality drinking water. View Nevada’s Watershed Plans to learn more.

connecting watersheds to the classroom

Get Outdoors Nevada supports Next Generation Science Standards, which uses inquiry-based approaches, science and engineering practices, and cross-cutting concepts. Watershed structure, maintenance, and functionality can all be utilized to study topics such as the water cycle, water conservation, and more. Investigation through experiments, data analysis, or creating watershed models for the local area are just a few ways to engage students in this action-based learning method. Students can relate to and retain knowledge connected to their world. Empower students by encouraging them to identify a problem within their community, research and analyze data, and provide solutions to create change. Our Water Resource Hub is an excellent source for water-related content pertaining to Southern Nevada.

Whichever approach you choose to teach your lesson, we strongly recommend visiting a local watershed site for an engaging, hands-on experience. Witnessing a watershed firsthand provides real-life learning opportunities, a connection to nature, and a connection to the community.

Students learning about the Las Vegas Wash on a field trip, Lake Mead NRA
A man and women sitting on he ground outdoors
A tour guide leading visitors with Lake Mead in the background

want to learn more?

Get Outdoors Nevada provides Nevada educators the opportunity to learn about and connect with nature through Teacher Workshops. For more information or to register, please visit our Events Calendar.