High temperatures, drought, and wildfires are three of the climate constants in the American West of the last two decades.
En America they call the errekas creek “said a Basque shepherd from Erroibar according to what a good friend of mine told me. This shepherd probably traveled the mountains of the Sierra Nevada and bathed in Tenaya lake, the mirror of the Tioga canyon, a step majestic flanked by two of the cathedrals of the Rockies, the Dana and Conness Mountains, which rise to almost 4,000 meters in height. A spectacular and magnetic place, whose beauty lies in the river basins, the snows and its spring streams. them, the High Sierra will die.
Not far from there, running 370 miles south along Route 395, is Hoover Dam, a symbol of the modern Far West and an important chapter in Roosevelt’s New Deal. 85 years after its construction, it faces a serious identity problem: It could no longer be a dam.
The Hoover, which rises more than 200 meters above Black Canyon on the border between the states of Arizona and Nevada, retains the waters of the Colorado River. There tourists can see the bas-reliefs art Deco by Oskar Hansen showing a series of titans steering a ship’s rudder, harvesting piles of wheat, standing under a plentiful waterfall and, like a cornucopia, lifting heavy weights above their heads. These images are a representation of the nature of the dam that, under the 1928 law, was built to control the flooding of the Colorado River, for navigation, irrigation, water storage, and energy production.
Less water level The dam that is 200 meters thick at its base and enough cement to build a one meter wide sidewalk around the equator. Lake Mead, the reservoir formed by the dam, is the largest swamp in the republic. But, as Ian James reported for USA Today, the Hoover is facing a water shortage of epic proportions.
The source of the problem is higher up in the Rockies, where extremely dry conditions in the high mountain basins have severely limited snow accumulation. In the last two decades there has been a 42 meter drop in the water level of Lake Mead, which is currently at 37% of its capacity. In 2020 alone the water level has dropped by about five meters and is expected to drop another three meters before the end of the year. Projections show that by the end of 2021 the water level will drop below the threshold of 327 meters, which is the federal limit to declare an emergency situation. This is likely to happen in August, causing the most severe water outages in Arizona, Nevada and New Mexico history. If the reservoir declines at the rate that has been predicted, further cuts in the water supply will occur in 2023, until a much more severe Tier 2 shortage is declared.
Hydraulic engineers face the lowest water levels since the dam was filled, getting dangerously close to the minimum. Its decline threatens the water supply to cities and farmlands in five states and reveals how the water management system is facing increasing risks.
Mike Bernardo, director of the engineering team that plans the Hoover’s water discharges, has announced that the dam’s normal capacity is 2,074 megawatts, generating enough energy per year to supply approximately 450,000 homes on average. Current water levels have reduced the dam’s capacity by 25% to 1,567 megawatts, which would generate power for up to 350,000 homes. For every 12 inches that the water level drops, about 6 megawatts of power generation capacity are lost. The lowest level at which the dam is capable of producing power is about 290 meters, which would generate about 650 megawatts. If the lake fell below that point, the dam would cease to be a dam, and would not be able to generate power.
The Colorado River has experienced wet and dry spells, but over the past two decades there have been 17 dry years, representing 77% of the total. Unlike the long-lasting droughts of the past, this “mega-drought” has its effects increased by pollution and global warming. Due to this aridification process, the river could lose a quarter of its flow by 2050: for each additional degree Celsius of warming, the average flow could decrease by 9%.
The impacts of drought in each state of the Union are compiled by the National Drought Mitigation Center (NDMC) which uses a system of five categories, from abnormally dry conditions (D0) to exceptional drought conditions (D4). At present we are in D4 in a good part of the states of Oregon, California, Nevada, Utah, New Mexico and Colorado. Under the NDMC, this assumes that there have been abnormally dry winters that reduce snow cover, and less snow means less water in streams. As a result, forage is reduced and desert plants implement reproductive survival mechanisms. Surface water levels drop and Lake Tahoe’s water clarity is higher than normal. Attracted by the need for water and food, the activity of bears and other animals increases in urban areas: Wildlife invades residential areas. Not long ago a cougar appeared in front of Cold Springs Middle School and a bear visited the campus of the University of Nevada.
drought and heat When extreme drought levels D3 are reached, alfalfa and hay production drops dramatically, pasture conditions worsen considerably, and producers sell livestock that the land cannot support. Increase fire activity; the fire season and the intensity of the same are extended and the water temperature rises. 90.85% of Washoe County is at D3 levels, but the southeastern two-thirds of the state of Nevada, where Las Vegas is located, is in a D4 situation, of exceptional drought: The levels of the reservoirs are extremely low, the hydroelectric power production is limited; levels of groundwater reservoirs decrease; water allocations to farmers and ranchers are reduced; there are restrictions on water consumption; fire danger increases and wildlife population decreases. In sum, the viability of the ecosystem is threatened.
Here in Washoe County, we’ve set a new record in 2021 – the fifth driest April in 127 years, with 0.68 inches of rain below average. Last year temperatures rose to 54 degrees Celsius in Death Valley, one of the hottest days on record on the planet.
According to Phyllis Diller it was always said that California does not have seasons, but it is not true, now it has four, the fire season, the flood season, the mud season, and the drought season. The latter is just the prologue to a new wildfire season of epic proportions. It is not a regional dilemma, it is a global problem; Nevada and California are our neighbors and the ashes from the San Joaquin Valley forest fires will reach the Bay of Biscay a few days later.
The Colorado River has suffered wet and dry periods, but during the last two decades there have been 17 dry years, 77% of the total
Last year the temperature rose to 54 degrees Celsius in Death Valley, on one of the hottest days on record