Cowles Commons


IF YOU MAKE A FRIEND WHO LIVES IN A CITY anywhere in the world, you can always immediately ask them the name of their river.  After all, a house can be supported by a well.  A town can be supported by a creek or a stream.  But only a river can support a city.

Just as a great river supports the life of a city, a great park is necessary to support the hopes and dreams of it’s citizens.  A park is where people go to be together.  It’s a place for children to play.  It’s a place for marriage proposals to be made and books to be read.  It’s a place for young people to dream of their future and a place for those who have lived a long life, to sit and reflect on the past.

Every great city has a public park at its heart, and Des Moines might now have the grandest of them all.


“In so many ways, Cowles Commons is the red carpet where we can welcome people from around the world to Des Moines,” said Laura Sweet, Vice President and COO of Des Moines Performing Arts (DMPA) and the primary project manager of the recent renovation of the site formally known as Nollen Plaza.  “Cowles Commons was designed to be the centerpiece of our community.”

The concept of renovating Nollen Plaza began to gain momentum in 2006 after a group of community leaders came together with an interest in transforming the park into a location that would benefit all the citizens and visitors of Des Moines while creating a world-class cultural and urban destination.  The profound impact of the project was immediately understood by everyone involved, and the team spent years considering the goals of the project and understanding the needs of the city’s many stakeholders.

The final project team was assembled by Jeff Chelesvig, DMPA’s President and CEO, and included internationally-renowned talent from San Francisco to New York.  The concept and vision was then brought to life by a team composed of top regional companies.

The landscape architect behind the project was New York-based KSLA.  The firm’s Principal, Ken Smith, is a Waukee native who completed his undergraduate training at Iowa State University before earning a Master’s in Landscape Architecture from the Harvard Graduate School of Design in 1986.  Prior to tackling Des Moines’ central park, he designed the Roof Garden of New York’s Museum of Modern Art, was a member of the THINK Team in the World Trade Center competition in 2002 and led the landscape for the “World One” project in Mumbai, India.

The design Smith created for Cowles Common features a large red carpet of paving stones that is flanked by the iconic “Crusoe Umbrella” created by Claes Oldenburg and Coosje van Bruggen, “Swirl” a dramatic new sculpture that features 8,000 LED lights and was created by San Francisco artist, Jim Campbell, and the new Lauridsen Fountain designed by Fluidity Design Consultants.




Weitz was awarded the Construction Management contract in late 2013 and immediately began to assemble a local team to complete construction on the project.

“From a quality-control perspective, it was an incredibly challenging project,” said Weitz Project Manager BJ Frideres.  “Perhaps one of the toughest in which I’ve ever been involved.”

The complexity arose from the team’s desire to strictly honor the geometric design created by Smith and KSLA.  The entire site, from the largest sculpture to the smallest plant is carefully placed in a giant grid pattern that is aligned to true north.

“We were working with tolerances down to 1/32 of an inch on the pavers,” said Frideres.  “As a result, the job really required a team that was committed to the design and respectful of the process.”

“Our mantra for the project was ‘zero tolerance,’” added Nick Cimaglia, a construction manager with Perficut, the firm retained to plant and maintain the garden.  “Our team was out planting with string lines and tape measures, and even then there were times when we would take a second look and realize that we needed to move a plant an inch to the left or right, or even up or down.”

“Of the 12,000 plants that were installed, each was very specifically planted for a color palate and location,” said Sweet.  “We were really counting on Perficut to maintain the integrity of Ken Smith’s design as there are important lines that connect [the Civic Center] to Cowles Commons.”

“In addition to the installation of new plants, we also had to maintain and protect the existing trees,” said Frideres.  “That meant Perficut had to wrap, mulch and protect the trees above the surface during the construction phase, while also paying particular attention to the health of the root system beneath the surface.”

Work beneath the surface was made particularly challenging by the fact that the site contains several buried buildings.

“Before Nollen Plaza existed, there were several structures on the site.  The buildings were demolished into the basement and covered in sand,” said Frideres.  “During the project, we pulled up concrete columns and rebar that was over 100 years old.”




The construction waste was removed and replaced with a high-tech subterranean irrigation system and Silva Cells, which were engineered to promote the health of the garden and trees.

“The Silva Cells are buried three feet under the surface beneath the frost level, then filled with a special soil mix and wrapped in fabric and mesh,” said Cimaglia.  “They improve the health of shrubs and trees by supporting the weight of the surface, reducing soil compaction and helping to direct roots.  In this case we also installed an underground irrigation system so that the garden and trees would remain happy and healthy no matter what our Iowa summers have planned for our future.”

“The trees are all in a much better situation now than what they had in those old four-by-four boxes,” said Frideres.

“When the project budget became a concern, Perficut also looked for opportunities to find savings through creative strategies that didn’t call for reducing the scope or vision of the project,” said Frideres.

“In some instances we could find slightly smaller plants that were more cost effective but would be of equivalent size when it came time to plant,” said Boka.  “We also reviewed our processes and determined that we could reduce costs by mixing soils off-site and then excavating and filling at one time.  Everything on this project needed to done perfectly and quickly.”

The new Cowles Commons opened officially in June with a series of victories of all shapes and sizes.

“I can’t tell you how rewarding it was to take my children down there to see what we had done and to play in the fountain,” said Frideres.  “Every time we go, we can see that people of all ages are really enjoying it.”

“For Des Moines Performing Arts, it has become a place where people can have informal meetings or enjoy an event that is somewhat more formal like Winefest,” said Sweet.  “So in terms of animating the space that has been created, the community has already shown the incredible potential that exists.  It’s going to be quite a lovely centerpiece for our community.”

Leave a Reply

Your email address will not be published. Required fields are marked *