The Santa Cruz River Valley in 1890, looking from downtown Tucson toward Sentinel Peak (“A” Mountain), when the river still flowed here. The photo was taken by Leo Goldschmidt, a grain mill owner.

The Santa Cruz River hasn’t flowed through Tucson in 70 years — but some local officials would like to change that.

They’re in the early stages of examining the feasibility of introducing a “trickle” of highly treated effluent into the river through the downtown area. Theoretically, it would run from 29th or 22nd Street on the south to as far north as Speedway.

Those interested, led by Pima County Administrator Chuck Huckelberry, see a flowing river as a tool for environmental restoration and economic development. It could revitalize the western edge of downtown and the west-side area and become a major tourist attraction, supporters of the idea say.

But a Tucson Water official — whose agency controls use of most of the region’s effluent — says the high cost, environmental implications and regulatory challenges make reflowing the Santa Cruz all but a pipe dream.

The idea is one of several under consideration for upgrading the Santa Cruz riverfront through downtown. Another, which has been all but discarded as too extravagant, is creating something like Tempe Town Lake, storing Central Arizona Project water in a dam. Still on the table is bringing in a small amount of effluent to irrigate new mesquite and willow trees on the riverbanks, restoring the bosque that was there a century ago.

City, county, Rio Nuevo and downtown economic interest groups have been involved in the discussions and say it will take time to determine if any of the ideas are workable. Money to pay for them would probably have to come from a county bond issue that could go before voters in 2015.

A decade ago, the U.S. Army Corps of Engineers studied and rejected as too costly the idea of reintroducing water into the river. The Corps said putting water into a 7.5-mile stretch would cost $100 million.

Today, Rio Nuevo officials are open to the idea on a smaller scale if it’s economically feasible.

“Water could be a boon for development and tourism by re-creating the riparian oasis that once existed there,” said Fletcher McCusker, chairman of the Rio Nuevo Board. “It would create a shaded area and bring wildlife and animal life, and it would certainly be a much more walkable area. It would be an opportunity to create something very accessible and very urban and yet keep some of our natural amenities intact.”

When the Urban Land Institute visited Tucson last year and wrote a report containing ideas for downtown revitalization, “if you look at all their drawings, every one of them had blue water in the Santa Cruz,” McCusker said.

“It depends on where you get it from and the cost of getting it there,” he said. You can’t just dump it into the river. You would probably have to create a subchannel. It’s a lot easier to say than to do. But if you go to Ina Road on the river and look north, the water in the river makes a huge difference in creating a riparian stream.”

Tucson Mayor Jonathan Rothschild said it’s a good idea and that he would “love to see it happen.” But he says financial constraints and environmental issues need consideration.

Tucson Water’s concerns include costs, the potential for effluent to cause groundwater contamination due to the presence of a nearby landfill, and regulatory obstacles, said Wally Wilson, Tucson Water’s chief hydrologist. Such issues “make these ideas extremely difficult if not infeasible,” Wilson said.

It would cost $2 million a year to have an 18-inch-wide, 6-inch deep stream through downtown, he said. That would require about 2,500 acre-feet a year, enough to water two golf courses over a year, he said.

The long-inactive landfill, covering about 85 acres, lies west of the Santa Cruz between Cushing Street on the north and Mission Lane on the south. The concern is that the effluent could leach contaminants in the buried garbage into groundwater.

“You’ve also invited the federal government into your house. You’re dealing with the Army Corps of Engineers and 404 permits when you do anything in the river. You bring in the federal government and things move at glacial speed,” Wilson said.

The Corps must issue a permit, under the federal Clean Water Act, to anyone wanting to dredge or fill federally regulated waters such as the Santa Cruz River.

But Huckelberry said the reintroduction of water and the mesquite irrigation scheme are feasible concepts that deserve support.

The County Flood Control District is prepared to improve the Santa Cruz River Park and the river bottom to make use of water and irrigate the mesquites, he said. The county has spent more than $600 million cleaning up effluent from two downstream sewage plants in response to a federal mandate, he said. The effluent can be transported to the downtown area and put into the river without more treatment, he said.

What’s needed is for the city to agree to use some of its effluent for this purpose, he said. A “conservation effluent pool” of 5,000 acre-feet a year has been created for environmental restoration purposes, he noted.

“Given our historical destruction of the essential riparian environments in the Sonoran Desert, we have an obligation to set aside effluent for the environment,” Huckelberry said.

He called concerns about contamination “bogus,” and noted that an old landfill along the Santa Cruz at Camino del Cerro, downstream from the Roger Road Wastewater Reclamation Facility, has done little damage. The only time that landfill caused groundwater contamination was when it was flooded in 1977 and 1983, he said.

The mesquite bosque restoration idea comes from Jonathan Mabry, the city of Tucson’s historic preservation officer. Restoring the bosque would add shade and a sense of place, he said. Authorities are also interested in planting trees along Mission Lane, running west from the river to the historic Mission Garden site.

Planting trees along the river would probably cost about $100,000 a half-mile, said Nanette Slusser, a deputy Pima County Administrator. There are also plans to improve The Loop bike path in the area at a cost of about $2.2 million.


Become a #ThisIsTucson member! Your contribution helps our team bring you stories that keep you connected to the community. Become a member today.

Contact reporter Tony Davis at tdavis@azstarnet.com or 806-7746. Follow him on Twitter@tonydavis987. His blog is at azstarnet.com/news/blogs/desertblog.