Along with overseeing the construction of the spring training facilities and stadium of the Chicago Cubs (upper right corner), the city of Mesa, Ariz., contracted a team of companies that worked side by side to build the massive Riverview Park on the 146-acre site. ValleyCrest Landscape installed all of the softscape, xeriscape and irrigation. FlexGround, a licensed landscape company, completed the more than 20,000 square feet of rubberized playground surfacing. AZ Rec Design installed play equipment from Dynamo Playgrounds. (Luke Pierzina, Extreme Photographer)

ValleyCrest excavated the planted areas and installed the irrigation systems: Hunter sprinklers on Rainbird controllers for the turf and Rainbird drip emitters in the xeriscaped planters. They also fine-graded the turf areas before hydroseeding and sodding. (ValleyCrest)

 

The large areas of turf were hydroseeded with paspalum. Smaller areas within the playground were sodded with paspalum but then had to be over-seeded with rye due to how late in the year it was. (Jackie Mercandetti Photography)

As parks come in all sizes, so too do the opportunities for landscapers. The submissions that LC/DBM received for this issue were proof of that, for example: a small playground whose safety surfacing was creatively crafted by Dave Monson Landscape, a regional park in Minnesota where the hardscape company Glacial Ridge rehabilitated the parking lots with permeable pavers, and a Houston city park that was greened up by Martin Landscape.

On the other end of the spectrum, sometimes parks are such extensive undertakings that even a company the size of ValleyCrest is just a player on a team working towards the objective. Such was the case in Mesa, Ariz., where a 146-acre site was designated by the city to become the spring training home of the Chicago Cubs, and the extensively bedecked Riverview Park.

The Lineup
Besides ValleyCrest, the installation team included Hunt Construction Group, FlexGround, AZ Rec Design, Dynamo Playgrounds, Integrated Design Solutions, Concrete Finishing, Siteworks, and Pacific Aquascape.

With all these players and more on the ground at any given time, the critical task of managing the game plan was headed by Ross Renner, Mesa's supervising engineer; assisted by representatives from Hunt Construction and the city, including Andrea Moore, Development and Operations Administrator for the Mesa Parks Department.

"I stay involved as we go through construction," she says, "making sure that the discussions that have occurred throughout the design process are carried through in construction."

The Field of Play
One of the main areas of the park was the playground. FlexGround, a surfacing company that holds a landscape license since it also does ground preparation, was in charge of the safety surface. Before any of their work began, utility and plumbing lines were run and the play equipment and shade structures were installed. Then FlexGround came in with their Bobcat compact loaders, excavated the area and leveled the sub-grade.

Next, they laid down type II ABC aggregate in two-inch lifts, wet it down and compacted it to a 95 percent compaction rate. The final depth of the aggregate is a minimum of four inches but because some areas of the playground needed less cushioning than others, based on the type of equipment installed and its IPEMA fall-height requirements, the aggregate is up to nine inches deep in places to provide a level surface throughout.

The actual safety surfacing product, which the company calls UltraFlex, is a two-layer system that was invented in Europe over 30 years ago for pool surrounds. The cushion layer is made from recycled truck and airplane tires that are shredded and then have all metals removed. The wear-course layer is EPDM or TPV rubber.

"It evolved as a playground surfacing material more from an ADA-compliance concern," says Bill Stafford, co-owner of the company. "Unlike sand, EPDM and TPV rubber make a nice, stable, durable unitary surface."

And there are no patents involved. FlexGround just purchases the materials from various companies. The wear-course rubber comes in a selection of different colors.

When the ground was prepped and dry, mortar mixers were brought in to combine the materials with urethane. As some crewmembers mixed, others transported the mixture with wheelbarrows to those on the ground who with guide rails and hand trowels installed the cushioning layer at the predetermined depths. Stafford said this part of the job took the 12-man crew about 15 days to complete the 20,000-plus square feet of area.

"Typically we can do 3,000 square feet of either layer in a day," he says.

The wear-course layer, which in this case was TPV rubber, was also mixed with urethane. It was installed in a ½-inch layer. Blue and tan were the colors selected for Riverview Park. This layer took about the same amount of time. Besides safety surfacing, FlexGround installs pool-deck surrounds, walking and jogging trails for elderly facilities, church entryways and walkways, even entire baseball and kickball fields for small children.This installation, according to Corey Hague, another co-owner of FlexGround, is one of the largest continuous rubberized pads in the United States.

"We worked closely with the other various contractors to make this dream a reality for the City of Mesa and the Chicago Cubs," he adds.

FlexGround did all of the base preparation under the safety surface, which entailed excavation of the existing ground with Bobcat compact loaders, and installation of type II ABC aggregate that was then compressed to a 95 percent compaction rate by vibrating compactors. The safety surface was installed in two layers: a cushion layer and a wear-course layer that is a half-inch-thick application. Both layers were combined with urethane - a 12 to 14 percent ratio for the cushion layer and a 22 percent ratio for the top - mixed on site with mortar mixers and hand-troweled into place. Guide rails were used to ensure a level surface. The materials totaled around 226,000 pounds. (FlexGround)

The 1,000-square-foot splash pad is ringed by 22 Medjool date palms. JLG extendable forklifts were used to place them. Ninety-nine more of the 16-foot-tall trees were planted throughout the park. (Luke Pierzina, Extreme Photographer)

The cushion layer was installed at different IPEMA-certified, fall-height depths depending on the type of playground equipment. Since the contractors couldn't slope the surface up and down to account for thicker cushioning in areas, they raised the sub-base up to five inches in the thinner areas instead of excavating deeper in the thicker areas. The climbing wall is GFRC shotcrete that was sculpted and then colored. Because of the extreme heat, it was necessary for the installer to pour the concrete for the wall around midnight to allow it to cure properly. For more information on fall-height depths, visit www.ipema.org. (Jackie Mercandetti Photography)

The landscape installation occurred concurrently with the playground surface excavation and installation so tight coordination was demanded. All the curbing that the playground butted up against had to be installed and cured first because the curing process of the surface will crack uncured concrete. The landscapers were able to install turf and test sprinklers while the surface crew finished up. All plants and turf are being maintained by city crews. (FlexGround)

Outside the Lines
"Typically, the landscaping goes on concurrently with the playground installation," admits Stafford. So cooperation is very important.

ValleyCrest was contracted to install almost all of the landscape and irrigation in the park and knew this to be true. According to Kristi Staley, the company's marketing communications manager, the project, "required tight coordination with lake construction, concrete construction, and playground installation in order to meet the completion schedule, which was fixed due to the start of spring training."

Turf and trees are blended with xeriscaped areas throughout the park. Most of the turf is paspalum that was installed by hydroseeding. However smaller areas within the playground were sodded with paspalum after the playground was finished. But due to how late in the year it was by then, those areas had to be over-seeded with rye. The irrigation system for the turf relies on Hunter sprinklers and Rainbird controllers.

The xeriscaped areas contain bushes such as oleander, cordia, red fairy dusters, jojoba, sage, and honeysuckle; various trees including acacia, olive, ash, elm, oak, and mesquite; and for mulch, 3/4-inch brown decomposed granite. These planters are irrigated with Rainbird drip emitters. Other tree varieties around the park are ironwood, blue Palo Verde, Medjool date palm, purple-leaf plum and Bradford pear. Any tree planted within 10 feet of a hardscaped area had a root barrier installed. Bougainvillea, bottlebrush, hibiscus and rosemary are among the other bushes. Accents include agave, desert milkweed, aloe, deer grass and yucca.

ValleyCrest reported that it took 35 people seven months to complete this widely diverse, impressive landscape that is being maintained by city crews. The work of these two landscape contracting companies, together with the efforts of the rest of the team that resulted in a 1,000-square-foot splash pad, a 5-acre lake, a 50-foot-tall pyramid net climber, a 10,000-square-foot, S-shaped ropes course, and a 300-foot-long climbing wall among other attractions, delivered a crown to the city of Mesa.