Water in the Desert

Water is our planet’s most precious resource. It makes up nearly 71% of the Earth’s surface and yet it’s more important than ever that people conserve it and care for it.

It’s no surprise to people living in Gilbert that the place we call home is in the middle of the desert. In fact, Gilbert only gets an average of about 7 inches of rain per year! What may be surprising to people, though, is how a town in the middle of the desert is able to ensure that water is available to all 240,000+ residents year-round! Let’s take a look at some of the data we have available to see exactly how much water we use in Gilbert, AZ and how those numbers have changed over the years.

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Gilbert's Water

First, we’ll start with a quick civics lesson about how water moves throughout a municipality and then break each piece down. This will help us understand the different stages of water use and how they tie in to the various resources we have in Gilbert. Take a look at this graphic and start with water at the source in the bottom corner:

The Water Cycle

Most water used by people comes from water sources like the oceans, rivers, lakes, and streams or from the ground where it’s pumped out. From there, it’s transported to facilities where the water is cleaned and treated before it’s delivered to homes, businesses, and lands. Once that water is used, the wastewater is sent down a drain and collected before it’s sent to a different kind of facility where it’s cleaned and treated yet again. Now that this water is clean again, it can then be used again (direct reuse), recharged, or returned to the source where the cycle starts over again. This process repeats over and over again and is the cycle by which nearly all water in Gilbert is used and re-used.

Let’s take a look at each step and see the details of how water is delivered to our residents.

Source Water

In Gilbert, our water comes mostly from the Salt River. As you can see in the map, our source isn’t exactly close to Gilbert. Luckily, throughout Arizona’s history, people and organizations have figured out ways to supply water all over the valley. The first major source of water is from the Salt River Project, a not-for-profit water and energy company. In addition to the water from the Salt River, though, Gilbert also gets water from the Colorado River. In the same way that water was routed from the Salt River, this water is brought to Gilbert by a 336-mile canal known today as the Central Arizona Project or CAP. Today, together with these 2 major sources, Gilbert is supplied with enough water to sustain all of the residents living here.

What happens once the water gets to Gilbert, though? Let’s take a look at some data!

This chart shows the total potable water production in Gilbert. In other words, the total amount of water that’s taken from our sources to be used, or consumed, by Gilbert residents.

Water consumption can be broken down into the following types of usage:

  • Commercial usage - The water used by businesses during the course of operation and also for building use.
  • Home consumption - The water used by single-family residential homes within the Town boundary.
  • Municipal use - The water used within Town facilities and landscaping for property that the Town owns.
  • Multi-family residential - This includes any apartments or other residential structures where there are multiple customers getting service but there is only one meter for the building.
  • Schools - Any water being consumed by schools within the Town boundary including public, private, and charter schools.
  • Unaccounted use - This is an estimated amount that is calculated from the differences between water production meters and reported consumption. While we strive to use as much of our water as possible, we typically lose about 6% of our water to leaks, mechanical issues, water main line breaks, and even to emergency use (in firefighting, for example).

Since Gilbert has been growing so quickly since 2001, it might make sense that, as the Town grows, our residents and businesses are using more water. If you look at the water production chart, though, that doesn’t seem to be the case. Let’s take a look at how Gilbert’s water production has changed as the population has increased.

It’s a bit interesting to see that, despite the jump in population growth, the Town hasn’t needed to produce more water to keep up with demand. On top of that, despite the fact that both SRP and CAP have raised rates on sourced water every year, Gilbert hasn’t had to raise its water production rates for almost 10 years!

How is this possible? In short, water conservation! Thanks to all the water conservation efforts in the Town, Gilbert is able to use nearly the same amount of water year to year. Let’s take a look at some more data to see what exactly “water conservation” means for Gilbert.

Water Reuse

Water conservation in Gilbert is an important part of the cycle of water use. There are two main ways that water is conserved - by minimizing the amount of clean, potable water that’s used from the source and by re-using as much water as possible. Let’s start with the latter.

In Gilbert, water that is used or consumed by residents and businesses is collected whenever possible. When you wash your hands in the sink or use the bathroom, the water that goes down the drain is sent to the sewer and that’s where most people stop thinking about it. The water that collects in the sewers, though, is still water and, with a little bit of treatment, it can be reclaimed and reused. In fact, 100% of the water that’s reclaimed and treated is reused within the Town!

Gilbert has two wastewater treatment or water reclamation facilities. Using the data provided by the Town, we can see exactly how much of the water that’s gone down the drain ends back up at these treatment facilities.

This chart shows the amount of incoming, or influent, water returning to the wastewater treatment facilities. As you can see from the chart, a significant portion of the water used comes to the treatment facilities. Let’s see how that compares to the amount of water Gilbert sources.

This chart shows how much water, in millions of gallons, comes back to the treatment plants compared to how much potable water Gilbert produces per year. While some of this influent water is unable to be treated, a significant portion of it becomes available for re-use and, therefore, reduces the total amount of water that Gilbert has to secure from its sources! Additionally, notice that the amounts from year to year tend to remain consistent. That consistency means that, despite the population growth, Gilbert’s water conservation efforts are working!

So what happens to the effluent water once it leaves the treatment plants? If we look at our first graphic, we can see that there are 2 ways that water is re-used - direct reuse and recharge. Let’s look at both of these methods and see what the data shows about how we use them in Gilbert.

First up is direct reuse! Direct reuse involves taking water from the water treatment facilities and sending it back via a special system of pipes that ensure that the water is used for irrigation, industry, and lakes maintenance throughout the Town. The chart below shows how much of the wastewater that is brought in is reused.

In this case, it’s interesting to see that the trend from year to year for reuse almost matches the trend for the actual wastewater coming in to our treatment plants. As more water is reclaimed from year to year, more of that water is able to be reused within the community!

The remaining water that isn’t reused is sent to reservoirs like the Riparian Preserve where it is recharged, or stored underground. This recharge water fills the 7 recharge basins at the Preserve where it percolates and filters back down into the ground so that it can be recovered later. This storage at the Riparian is enough water to provide the entire Town with an alternate water source for 7 years! In fact, the Riparian has stored over 18 billion gallons of water for future use since 1999!

Water Conservation

Now let’s talk about the other efforts happening in Gilbert to conserve water. Gilbert’s Water Conservation team is a key part of the Town’s ability to keep water costs down. Here are just some of the programs that our Water Conservation team offers for both residents and businesses in Gilbert:

  • Monthly Water Scoop - A monthly newsletter with water facts and programs happening throughout the Town.
  • Water Wise Gilbert - Get recognized at your business for saving water and money! Create a monthly water budget and hit your targets to get this distinction.
  • Free Water Checkup - If your water bill is higher than normal or you want to make sure your home or business is being water-wise, schedule a free water checkup and our team will diagnose the problem!
  • Water Calculator - See how much water you should be using both inside and outside your home. Compare the results to see if you can help save more water!
  • Free Landscaping Workshops - Help save water by learning about how to maximize your landscaping effectiveness while minimizing the amount of water you need to use.

As you can see, it’s not easy to make sure that there’s plenty of water for everyone in the middle of the desert. Gilbert is doing everything it can to conserve this resource of ours and make sure that it’s available to all residents and businesses.

What You Pay For
Why Rates Rise

Now that you’ve seen some of the data, see if you can use the data yourself to make other connections! Leave a comment if you have a cool water insight to share or download the water data sets from our Open Data Portal.

Finance and Operations

Transportation and Facilities