Tucson's Rivers Past and Present

Tanque Verde Flow Title Photo
Historically, our rivers flowed perennially (year round) or intermittently (flowing long after rain ceased). We had mesquite bosques and cottonwood and willow galleries across our city. In the present, we see more ephemeral flooding (quick flows after rainfall), which do not support our native riparian vegetation.

The Ever-Changing Santa Cruz River

From early to mid-1900s, these creeks and rivers dried up due to extensive groundwater pumping. Among the pressures on groundwater were growing population and associated urban development, mining, and agriculture. [1] Today, most of these creeks and rivers flow only after heavy rains, with just a few patches of perennial stretches. In our Fall 2019 newsletter, we illustrated where rivers and creeks are flowing year-round, seasonally, and only after rainstorms. [1] Glennon, R. (2002). How Does a River Go Dry? The Santa Cruz in Tucson. In Water Follies: Groundwater Pumping and the Fate of America’s Fresh Waters (pp. 35–50). Island Press.

1919

The Santa Cruz River seen from the southeast slope of Sentinel Peak. The river is flowing with partial vegetation cover on one bank and farmland on the other. Photo credit: USGS, SCRAM., 1919, s(1306), Sykes.

2003

The Santa Cruz River from the side of Sentinel Peak (A Mountain); the road in the foreground is Starr Pass Blvd. The agricultural farming is gone as well as much of the floodplain and riparian vegetation. Photo credit: USGS, SCRRR, 2003, s(1102), Oldershaw.

1942

The Santa Cruz River seen from facing south toward the Santa Rita Mountains. Pictured is a vast mesquite bosque (forest), a highly productive riparian habitat found in the desert. Photo credit: USGS, SCRMH, 1942, s(0937), AZGF.

1989

The Santa Cruz River seen facing south toward the Santa Rita Mountains. In place of the mesquite bosque from 1942, there is a dry river bed with little to no vegetation. Photo credit: USGS, SCRMH, 1989, s(0937), Turner.

Our Memories of Flowing Rivers

Community stories about Tucson's creeks and rivers

Santa Cruz River ~ 1930s

"I lived in a little adobe house that was built by my landlord in the '30s from an adobe pit in the backyard. He had stories about when he lived there in the '30s. The river was flowing the and it was not marshy, but it was lush down there by the river. There were plants and those big reeds, the carrizo." ~ Berta

Santa Cruz River ~ 1950s

"It wasn't running much but they built a little lagoon just south of Congress, and they put in little paddle boats where you could take your girlfriend out there and be romantic in the moonlight. The water was all fed by the Santa Cruz, but it was barely running." ~ John

Rillito River ~ 1994

"There were these big cottonwood trees that got uprooted when the river bank eroded. They were somewhere between four and six feet wide. We were speculating how old these things might be. When my colleague [from the tree ring lab] sampled them, we saw that the trees weren't that old, but they were huge. These trees that grow by the water, wow they really grow fast. Now there aren't that many big cottonwood trees along the Rillito." ~ Gregg

Sabino Creek ~ 1950s

"Sabino coming right out of the mountains up there would just roar, and that was a rocky, stony area. It would change the look of the river when we had big floods. So way back, that water would channel to farmland below, and they would use the old sloughs to drain the water down to where the flatter land was, where they could raise crops. Then that ran into the Rillito and together that became a real water source for the whole city." ~ John

Our Rivers Now

Through our Flow365 Monitoring Program, volunteers across the city collect data on our creeks to help tell the current story of our rivers. With this dashboard, you can see what's happening in our creeks and rivers today, last week, or even over the last year! It is updated anytime a community member collects data.

River Restoration Efforts in our Watershed

Middle and Lower Tanque Verde Creek

The River Run Network has focused efforts on removing Arundo donax, an invasive plant species, from this section of our watershed. We have been working in the area since 2021 and have successfully restored 75+ acres of riparian habitat from this shallow groundwater area.

Lower Sabino Creek

This creek has been monitored by our Flow365 Monitoring Program since 2016 and has perennial (year round) flow in a half mile section. We have been working to understand water quality in this area and supporting restoration upstream with rock structures to slow, spread, and sink the flow into the ground and encourage groundwater recharge.

Upper Rillito

Though this area may be dry for much of the year, there is still water beneath the surface. Within 50 feet, to be exact. This shallow groundwater supports cottonwoods, willows, and an elderberry tree grove just upstream of the Craycroft Bridge. We are working in this area to keep it clear of invasive Arundo and support slow, shallow flows that encourage groundwater recharge.

Cienega Creek

From river restoration workshops to supporting the beaver release, Cienega Creek holds an special place in the heart of the River Run Network. This creek is perennial in some stretches, creating important habitat for riparian species like gila topminnow, fireflies, and beavers! We are excited for the beavers that have been released in the area (Fall 2025) to thrive and grow the riparian habitat along the creek.