AMWUA Blog

Apr 22 2019Share

Drought and Shortage: What Is the Difference?

By Warren Tenney

The terms drought and shortage are commonplace in conversations across the arid State of Arizona and although they are used together regularly, they are uniquely distinct.

Drought is a prolonged period of less than average precipitation - meaning we are accumulating less moisture.

Shortage is an inadequate amount of water available to meet demands.  A shortage is not necessarily tied to weather.

Although both involve a lack of water, their circumstances, impacts and the challenges they bring differ.

DOES DROUGHT MEAN THERE IS A WATER SHORTAGE?

No.  A drought does not necessarily result in a shortage.

Limited precipitation and extended cycles of drought are the norm in the desert. Arizona’s current drought is in its second decade, surpassing the worst drought in more than 110 years of record keeping. Research shows that drought cycles in Arizona can run 20 to 30 years.

Despite the current drought, there is no shortfall of water for use by the cities in central Arizona because they have prepared. AMWUA’s members have planned, built, and managed their communities and their water supplies with drought in mind, ensuring adequate water to meet the needs of their residents and businesses through the past two decades and even as the drought continues. Being efficient has been a part of long-term water management in the Valley and has prevented a shortage of supplies during drought.

WHAT ABOUT A COLORADO RIVER SHORTAGE?

A looming shortage on the Colorado River has generated a lot of discussion. However, it is important to note that this would be a shortage of only one specific water supply.  It does not necessarily mean our collective supplies are insufficient to meet the water demands of our customers.

The AMWUA cities have a diverse water portfolio in addition to Colorado River water, which includes the Salt River Project (SRP), reclaimed water and groundwater. The Colorado River system, which provides less than half of the AMWUA members’ collective water supplies, has experienced its own extensive drought conditions for the past 18 years.  Due to over-allocation exacerbated by drought, Lake Mead has dropped to historically low reservoir levels.  However, cities have been preparing for a shortage on the Colorado River for decades.  The cities supported the approval of the Drought Contingency Plan (DCP), which is another example of the continual effort to protect our water supplies.  It’s important to note that shortages on the Colorado River does not mean shortage at your tap.

ARE THERE DIFFERENT KINDS OF SHORTAGE?

Yes, a shortage may impact one water source while others are not affected.  A shortage can also have different levels or tiers. For the Colorado River, this is demonstrated by DCP. Although there is no immediate impact to our municipal supplies, DCP specifies that if Lake Mead’s level falls below 1090’, a “Tier 0” shortage is in place. According to the April 24-Month Study, we will hover just under that level come the end of the year. While Tier 0 shortage does require mandatory reductions in Colorado River water, the volume of these reductions is actually very similar to what Arizona water users have already been voluntarily conserving in Lake Mead for years. As a result of this water stewardship, Arizona will not face any significant impacts with a Tier 0 shortage.

As elevations in Lake Mead continue to decline, eventually different levels of shortage will take effect. It is important to understand that due to Arizona’s priority system, our municipal supplies will NOT be reduced in early tiers of shortage. And if needed, each city has a plan to address any deeper shortages that may impact their supplies.

HOW ARE WE PREPARED FOR A SHORTAGE?

The AMWUA members are committed to protecting the long-term sustainability promoted by the Assured Water Supply Program. We do not just plan ahead for next year’s water, but for the next century. It is this forward-thinking mindset that allows our municipalities to weather decade-long droughts and drives your community’s water managers to negotiate fiercely on your behalf to protect these water supplies. They have invested in infrastructure, different sources of water supplies as well as underground water storage to ensure diversity in their resources to remain resilient for the long-term.

WE HAD A WET WINTER. ARE WE OUT OF DROUGHT?

Drought periods may have wet years and sometimes even severe flooding, but that does not mean the drought is over.  Historically and realistically, it would take multiple years of greater-than-average snow and rain to begin to heal the wounds left by the current drought.

IS THERE ANYTHING WE CAN DO TO GET OUT OF DROUGHT?

Drought is a part of our long-term weather cycles here in the desert. Unfortunately, there is no single action we can take to end drought. However, we can do our part by working on our ability to withstand times of drought. Conservation and efficiency are our way of life in the desert, and it is particularly important during drought. Being careful stewards of water can help reduce the impacts of drought on our water supplies.

With multiple sources of water, tough water laws and a strong conservation ethic, any shortage will not come as a surprise.  We have developed our communities with a keen awareness of the need to plan for extended dry periods, to capture and store all the water we can, and to manage it as efficiently as possible to stretch those supplies. Significant challenges may come, but thanks to sound water management we are prepared.
 

For 50 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit www.amwua.org.

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