Once upon a time cottonwood trees and riparian plants lined the river banks. Fish swam in the waters, and wildlife thrived.

Over 12,000 years ago early nomadic people found our desert to be rich and welcoming as they paused here in their hunter/gatherer lifestyle. Around 4,000 years ago people began to settle permanently and plant their crops at the base of Sentinel Peak (A Mountain), along the Santa Cruz River. The agrarian community grew. And the rivers flowed.

The mid-1500s marked the beginning of the Spanish influence, from explorers and gold seekers to missionaries and their accompanying military presidios. By the 1700s several missions had been established to convert the Indians to Catholicism. Still a Mexican village of a few hundred, the population of Tucson continued to grow. And the rivers still flowed.

The mid 1850s saw the influx of Anglos from the east. The U.S. government bought southern Arizona from Mexico and encouraged Americans to move westward. Tucson continued to grow. Residents dug shallow wells to access water. And still the rivers flowed.

By 1900 Tucson’s population was about 7,500. A municipal water system pumped and delivered clean water. Indoor plumbing did away with outhouses. Homes had the luxury of running water. Ten years later, the population was 13,000. Due to pumping and diversion for irrigation, the water table dropped enough that the flow of the Santa Cruz River could no longer be sustained. Water flowed above ground only after a heavy rain.

In 1922, recognizing the need for water in the arid west, the seven western states that bordered on or fed water into the Colorado River drew up The Colorado River Compact, allocating a specific amount of the river’s water to each state. Oddly, they based their figures on several unusually wet years which meant that, in effect, they over-allocated the contents of the river during normal flows. Further, when Mexico later pointed out that the river had its mouth in that country, more acre-feet were allocated out of thin air. Ah, well. For the most part that didn’t pose any real problem since there was more water than was needed at that time. When drier times followed the issue was ignored. 

Tucson’s population grew during and after World War II. Modern technology made it possible to pump ever deeper for water. However, by 1960 it was clear that continued pumping was unsustainable and would lead to serious subsidence of the land. Eventually the building of the Central Arizona Project (CAP), a 336-mile canal to bring Colorado River water inland for the cities and farmers, seemed imperative.

By 1980 the population surpassed 500,000, and deep pumping continued. Finally, after 20 years of construction, the CAP finally reached completion in 1992. But joy over this “endless” source of water was short-lived when the new water’s chemistry/ph effectively scoured out years and years of deposits and rust from the city’s old pipes and delivered brown, smelly water to people’s homes. With massive water main breaks and leaks, that expensive disaster set back the use of the canal for another decade.

At the turn of the 21st century, the plan we use today had been implemented. Water from the canal is diverted into a series of shallow “recharge” basins from which it filters through the desert floor into the aquifer (basically an underground “valley” filled with gravel and sand) below where it can be stored and pumped out by Tucson Water for delivery to the city. You can easily see some of these basins from the Desert Museum. At this time, depending on where you are in Tucson, around 80% of the water that comes out of your faucets has the Colorado River as its origin.

And that brings us to the dilemma we face today. With ongoing drought and the impacts of climate change, the level of the Colorado River is dropping with no end in sight. Lakes Mead and Powell, the nation’s two largest reservoirs, are well below half and likely to continue to fall. If that continues, the mighty Hoover Dam will no longer be able to generate electricity or even release water downstream.

Yikes! What can we do to forestall disaster? For starters we can recognize that we live in a desert where water is precious. We must be mindful of the amount of water we use. Let us look back and learn from Tucson’s earlier residents. Since they had to haul it from the river (or the well), you can bet they didn’t waste it! The Reid Park Zoo offers some great examples and suggestions. As you walk around, read the signs to learn all that the Zoo is doing to conserve and what you can do at home. And rest assured that water conservation is already a priority in the plans for the Reid Park Zoo expansion.

Grow shade on your property to help it stay cooler and hold moisture in the land. Sculpt your yard into basins and swales to capture and slow the flow of any rain that falls. Plant native trees and bushes next to or in your basins.  Give water a second use. Direct water from your washing machine, shower, and bathroom sink outside to feed a thirsty plant.

In front of the Zoo’s Conservation Learning Center (CLC) there is a huge rain cistern to collect rainwater from the roof to use as needed during dry times. You may be amazed by how much water can be collected from one monsoon storm. For example, from a 1,000 square foot rooftop (25’ x 40’), if a single inch of rain falls, 600 gallons of water will flow into the tank. Since many people live in houses that are 2,000 square feet, that would mean 1,200 gallons of water! When you consider the rooftop space of the CLC, you’ll realize why that cistern is so gigantic.

If you’re a Tucson Water customer, check out the amazing rebates available to help you pay for installing rainwater and gray water harvesting systems.

In a normal year, Tucson receives 10-12 inches of rain. When you convert those inches into gallons, the surprising but calculated fact is that the amount of water used by the city of Tucson is LESS than the amount of rainfall! If we can harvest enough rain, we wouldn’t even need the CAP water.  We don’t need expensive, complex equipment and technology. We simply need the will to take up the challenge. When we do, we may find that in fact it doesn’t feel like pain and sacrifice; it feels like satisfaction and success. 

And our rivers can flow again.

Walking the Walk

Supporting the Reid Park Zoo expansion is a win-win-win for Tucson, for conservation, and yes, even for the fight against climate change.

NASA defines climate change as a “long-term change in the average weather patterns that have come to define Earth’s local, regional and global climates.” Every summer here in Tucson, you’ll hear somebody say, “It’s hotter than it used to be!” and if you’ve lived here for a while, I’m sure you agree, as do scientists. Rising or falling temperatures globally has huge implications for us as humans, and of course for the animals in the ocean, on land, and in the air. 

It’s hotter and there’s less water available? This is bad for animal reproduction and survival, and ultimately for our own. Floods and tornados? They cause habitat loss for animals and habitation loss for humans. Heatwaves (we can relate) and wildfires? In the last year, and especially in the west, we’ve experienced  major damage to and loss of native plants, species, and human dwellings.  

Catastrophic weather events seem to be increasing, and we’ve seen the frightening way they can instantly upset the delicate balance of ecosystems and the amazing biodiversity our planet supports. But can we as individuals do anything to mitigate climate change right here in Tucson? Absolutely.

Here are a few simple things you can do, right away, to fight climate change

  • First, try to decrease the number of things you throw away.  For example, store your leftovers in reusable storage containers, and especially get a real water bottle which can be refilled over and over again. 
  • Try reusable grocery bags (they cost about $1 at most local stores), or if you do get the plastic ones from the store, take them back there for recycling the next time you shop.    
  • Recycle whenever you can, because recycling something like a soda can uses less energy than manufacturing a new one!  It doesn’t sound like much, but tossing that can into your recycle bin can save enough energy to run your television for three hours!  
  • Use less water, by taking showers instead of baths, or the big one – turn off the water while you brush your teeth.  It’s amazing, but this one small action can save up to 200 gallons of water a month, especially important here in the desert.    
  • Eat more vegetables! Mom would approve, too. Try having just one meatless meal per week – you’ll improve your health, you’ll save money, and you’ll be helping to reduce greenhouse gasses.
  • Pass one of these tips on to one other person! That is how positive change begins and grows.

The most effective way for us all to mitigate climate change, though requires a somewhat greater change to our habits: limiting the use of fossil fuels in our daily lives. It might not be in reach for you to purchase an electric car or convert your home to solar energy, but you can make a decision to walk or bike to nearby places rather than driving there, or  to carpool, or even to use public transportation when you can.      

A VERY green place, literally and figuratively

Where can you find more information about what you can do to start making a safer and more sustainable world for all of us?   

How about visiting the Reid Park Zoo? As an accredited AZA (Association of Zoos and Aquariums) member institution, our Zoo has already made a commitment to protecting the animals in their care, as well as their habitats and relatives in the wild. The Reid Park Zoo supports numerous conservation initiatives, inside the zoo and abroad, but their commitment to the mitigation of climate change may not be as well known. Let’s state for the record that the Reid Park Zoo definitely walks the walk when it comes to creating a more sustainable future for us all!


Three of the newest buildings at the Zoo, the Conservation Learning Center, the Elephant Care Center, and the amazing Animal Health Center, were built using “green” construction. This includes solar power, highly efficient HVAC systems, and the use of recycled and sustainable materials. For example, the ceilings in the Conservation Learning Center (CLC) are made from recycled jeans – really! That’s not all – the buildings incorporate natural lighting whenever possible and were finished with non-toxic, low fume paints and adhesives. The Reid Park Zoo even received a LEED Platinum certification from the U.S. Green Building Council for the amazing energy efficiency and sustainable construction of the CLC, and it was the first building in Southern Arizona to receive this prestigious designation.

Recycling and water usage

Everywhere on the grounds, the Zoo participates in the City of Tucson’s blue barrel recycling program, and recycle bins are everywhere to encourage guests to participate too. The Zoofari Café serves  tasty food on biodegradable dishes. In the gift shop, your purchases will never leave the store in plastic – you’ll receive a paper or reusable bag. The only straws allowed anywhere in the Zoo are part of reusable water bottles or souvenir cups. And right now, the Zoo is transitioning from the sale of plastic water bottles to reusable aluminum ones. Luckily, you can now find a “bottle fill” water station near the front entrance, so feel free to bring your own water bottle from home.     

Speaking of water, the Zoo needs a lot in order to keep the animal habitats clean and the grounds lush and green. But they use gray water – highly treated wastewater, also called reclaimed water, for these purposes. Even this water is conserved, because the keepers use low-flow, highly pressurized hoses to clean the animals’ indoor environments.

It’s not too late

According to scientists from NASA, there’s a chance we can still avoid the worst effects of climate change. The Reid Park Zoo is certainly doing its part, and they’re ready to help us do the same. And it’s a sure bet that the new construction in the Reid Park Zoo expansion will be the greenest in town!