Now how many of you when you hear Las Vegas, think of a wetlands located only about five miles from the famous Las Vegas strip? Well I didn’t…I think of Las Vegas, I think the strip, the desert, mountains in every direction, wetlands not so much. So where and why?
Anyone who has spent any time here in the desert knows what a wash is, for those of you that have not been lucky enough to have been here I think the easiest way to describe a wash is a dry river bed, most washes are named like a river, all washes move water, they snake through the areas seeking the best path to get the water to the lower altitude. The differences are simple rivers and creeks move water as it escapes from flatter more moderate areas with more vegetation, that water comes from rain or snow melts from those areas. The washes are dry more than they are wet, they carry water from rain or snow the same as rivers, but rain in the desert is not as commonplace, and there is not as many areas to absorb the moisture so there is a lot more run off and more importantly it runs off much quicker. This is the reason people get caught in these washes, because it happens too quickly. An inch of rain in the Midwest will see the majority of it absorbed into the soil while an inch of rain in the desert just runs away to the closest wash. So far two months into 2020 Clark County has received 0.27” of rain, while 2019 seen 4.43” of rain, with the “monsoon season” is late June through September but in most years the average total yearly rainfall is only 4.19”. So the washes only get used when there is a substantial quantity of rain.
The wet land park is located on the Las Vegas wash, and when we visited the other day there was a good quantity of water flowing through the park, on its way to the Colorado river and Lake Mead. 90% of Las Vegas’s water is drawn from Lake Mead, so everything from this wash is flowing into the potential water supply for Las Vegas.
Las Vegas Wash is a 12-mile-long channel which feeds most of the Las Vegas Valley’s excess water into Lake Mead. The wash is sometimes called an “urban river”, and it exists in its present capacity because of an urban population. The wash also works in a systemic conjunction with the pre-existing wetlands that formed the oasis of the Las Vegas Valley. The wash is fed by urban runoff, shallow ground water, reclaimed water, and storm water. The wetlands of the Las Vegas Valley act as the kidneys of the environment cleaning the water that runs through it. The wetlands filter out harmful residues from fertilizers, oils, and other contaminants that can be found on the roadways and in the surrounding desert.
Before development in the valley above the wash, it was able to contain the flows from rain water that fell in the valley and hills above. When the first sewage treatment plant went on line, the flows began increasing to the point that the channel expanded in size as the increased flows eroded the wash’s stream-banks.
This erosion also deepened the channel draining one of the largest desert wetlands in the U.S. southwest as the water flowed down the channel rather than flooding the wetlands area. This has had several consequences among them, increased flows of silt into Lake Mead, fewer migratory birds, reduced water polishing, from the native plants, and infestation of invasive plant species such as African Tamarisk (Tamarix africana) and Sahara Mustard.
The Clark County Wetlands Park is the largest park in the Clark County, Nevada park system. The park is on the east side of the Las Vegas valley and runs from the various water treatment plants near the natural beginning of the Las Vegas Wash to where the wash flows under Lake Las Vegas (through two seven foot pipes) and later into Lake Mead.
One purpose of the park is to reduce the environmental impact of the waste water and storm water runoff leaving the drainage basin area, by building a constructed wetland. This is being accomplished by installing a series of water flow control structures such as dams and weirs and by creating ponds that together slow down the flow of the water, catching silt, and reducing the undercutting of the dirt walls that form the wash. As of June, 2005 nine of these structures were operational.
The sides of the wash are being stabilized by installing Native plants and large pieces of demolished construction debris. Some of the native plants, especially those in areas of standing water, also help purify the water by removing various pollutants as the slow moving water provides these plants with nourishment. This method of purification is also called natural water polishing.
The second purpose of the park is education. The displays within the park show visitors how the wash looked before major settlement occurred in the valley and the impact people have had on the environment.
The park has a nature center with displays about the park’s plants and animals. There are miles of walking paths. The park covers 2900 acres, and is home to many species of birds and animals, while certainly worthy of a visit, much of the information about the park I found on line instead of being front and centre at the park, the main features of the park weren’t put forward, and seemed to be masked by the nature side of the park. This area had been an oasis in the desert for centuries and then was all but lost by the urban development, and now after seeing the destruction that been done to it, has be recreated to do what it had been for years. Their films running in the auditorium were informative about some of the park but were all ten years old, the story boards around the park were faded beyond being readable, we saw lots of disregard for the purpose of the park from simple litter to the tones of debris as the wash dumped into the park. I just feel as great of achievement the reconstruction of the wetlands has been it is being lost on most of its visitors.