The climate of Utah is characterised by heat and drought. The second driest state in the USA, Utah has many dams and canals built by the man. Today this complex water supply system provides water to meet the needs of 2.9 million people. Lack of precipitation was compensated by more groundwater pumped, and because of abundant rains water was pumped out to the desert. People learned to control water. Several times the residents of Utah were on the brink of real drought. Luckily there are mountains blessed with lots of frozen water and a little extra snow would always save the day.
People started establishing the first settlements on the territory of the today's Utah about 150 years ago. But there is evidence that the climate of the earlier past - a paleoclimate - differed much from the one the modern residents have got accustomed to. According to the data stored in tree rings the area used to experience the periods of drought that lasted much longer and were more severe. These mega-droughts were not only common but periodic, and would happen every 50 years or so. The droughts of the 1930s and 1950s were much less severe than droughts of the hundred years before. Utah's most recent drought of 2000-2004 that caused the water level of Lake Powell drop record low was the worst in 800 years for its intensity, but its duration was relatively short.
The most recent draught on the territory of Utah was in 2013, when all Utah counties were declared as drought disaster for the second year. That year in Salt Lake City the daily minimum temperatures broke the previous record and shattered it by 3 degrees Fahrenheit! In addition, by September 2013 more than half of Utah's reservoirs were below 50% of capacity and dropping. Record high temperature combined with low water level influenced water quality. By late summer most lakes had shallow water full of mud and stench.
What Utah Needs is Winter with Big Snow.
During the past 60 years, precipitation of Utah has had a clear oscillatory pattern with the change of wet and dry periods every 10-15 years. This peculiar "wet/dry cycle" is influenced mostly by the slow change of warm water pools of the Pacific Ocean followed by the transition to cool water over each six years or so. Winter precipitation over Utah is affected by this cycle. Knowing about this cycle scientists are able to forecast Utah's precipitation change. It should be noted that this Pacific influence is different from El Nino/La Nina phenomenon which only accounts for less than 20% of Utah's precipitation change. Even such a minor influence prevents making reliable forecasts for more than just a month.
Still the researchers have been working hard to improve their forecasting abilities. In 2010 scientists have predicted that the weather of 2012 and 2013 will be the driest of the 10-15 year wet/dry cycle. And the winter of 2013-14 will have a close to normal, slightly warm and dry snow season.
Back-to-back drought makes water managers worried. The reason is that drought lasting over two years quickly decreases water reliability and severely strains water supply systems. The bulk of Utah's territory depends on groundwater for minimum 70% of its public supply. And while a diminishing snowpack in the mountains is quite visible, falling levels of groundwater are hidden from the eyes of the public. In fact, the groundwater levels across Utah have been steadily declining since the 1970s and this constitutes a threat to farming. As people need more groundwater rural communities and wildlife can be threatened as well. In addition, numerous researches prove that Utah's groundwater fluctuates in accordance with its 10-15 year wet/dry cycle. This means that droughts that last for several years can accelerate groundwater depletion.
What Is Being Done?
It is known that water supply of the Colorado River is unable to meet its current water demand any more. To help eliminate predictable water shortage, a special water conservation programs has been developed for the state of Utah. The goal of the program is to reduce water supply by 25% by 2050. However, due to anticipated population growth an extra 540 million cubic meters will be required. And this can be a problem under variable climate conditions. Solving this problem calls for the united efforts of a wide range of experts specialising not only in climate science but also in hydrological engineering, water managing, etc.