Treading New Trails

Although the Salt River supported a thriving civilization hundreds of years ago, for the past century it has been a lot like Rodney Dangerfield: It got no respect.

The river, also known as Rio Salado, cuts through the heart of Maricopa County and has been the Valley's dumpsite for ages.

Dams to control flooding and provide irrigation dried up the riverbed generations ago and also created an easy spot to dump waste. Tons of old tires, demolished concrete, refrigerators, scrap steel, batteries and just about every other form of trash made their way into the riverbed, which flows from northeastern Arizona into the Valley.

advertisement

Now, after decades of abuse, the city of Phoenix is teamed with the Army Corps of Engineers and Stronghold Engineering to create an asset from an eyesore. After 10 years of planning, design and construction, contractors are well on their way to returning the abused waterway to its original condition.

"The amount of debris we have pulled out of the riverbed is just incredible," said Ron Talbott, a senior project manager for the Phoenix office of Stronghold Engineering.
"We want to create a place where people can enjoy the natural habitat rather than have an eyesore."

Phoenix officials have ambitious plans for the riverbed. This initial project, stretching from 19th Avenue along the riverbed to 24th Street, is the first major phase of an aggressive plan to rejuvenate the Salt River all the way to 115th Avenue.

Engineers are working on a feasibility study for a restoration project between 19th Avenue and 83rd Avenue. The city hopes more federal funding is available in 2006 for further studies and work.

The federal government funded two-thirds of the $99 million project, with local funding for the remaining one-third. City officials hope to wrap up this first, 5-mi., 600-acre section in early 2005.

The project is one of the largest habitat restoration jobs in the nation, and other cities are eyeing the success of the program, Phoenix officials said.

"We feel like we are getting some real bang for our buck in repairing this riparian habitat in the center of the city," said Karen Williams, city of Phoenix Rio Salado project coordinator. "A lot of the project's cost has been hauling away the debris and trash that people have dumped in the riverbed for years. That's why this project needed to be done."

Crews from R.E. Monks, a Phoenix contractor, started the project's first section in 1999, constructing a low-flow channel in the riverbed bottom and transplanting vegetation to create a natural riparian habitat with native plants. Water will circulate through the channel and provide a wetlands area.

Stronghold Engineering won the last three contracts on the project. The firm is responsible for the mid-level terrace and the top bank. Nature trails, rest areas, bathroom facilities, parking and grand entrances with steel canopies are planned.

Contractors are using gabion walls to reinforce the slopes and hold them in place.
Once the project is completed, the riverbed can withstand a 100-year flood event.

"For the most part, we stayed away from the banks, but if they were unstable, we reformed them," said Dan DeSemple, a CH2M Hill Engineers project manager in Phoenix. "Our goal is not to change the contours of the banks by more than a foot."

Designers decided to give much of the debris a second chance, with concrete beams and slabs morphed into benches and small bridges crossing the water features in the riparian areas. Unsuitable concrete is pulverized into a rock mulch to use in planting.

Volunteers are also planting native trees such as cottonwood while crews from Stronghold Engineering wage an aggressive battle against invasive plants such as salt cedar. Already, a "100-tree forest" has sprouted near an initial design-build wetlands test area.

"There's a tremendous effort to reuse and recycle as much of the debris as possible to tell the story of a river abused over the centuries," said Jeff Engelmann, vice president of Phoenix-based J-2 Engineering and Environmental Design LLC.
"Something like this has never been done before in United States so we are treading new ground with the Corps of Engineers."