The Hayfield site is located on what was once an old agricultural field on a level terrace that is situated above the Salt River flood way and would only be subject to flood flows that are in excess of the 100 year flood.

Construction on the Hayfield Site began in the Spring of 1995. As with all the demonstration cells, construction was completed by ARCHON, Inc. Each of the sites was primarily planted with soft-stem bulrush (scripus validus) from Kingman, Arizona, and three-squared bulrush (S. olneyi) from Casa Grande, Arizona. Since 1995, over 200 live trees and seedlings have been planted.

	This is how the site looked at its original planting in 1995. Planting was completed by the contractor, Western Sod, and with the help of City of Phoenix Employees.
	After a few weeks, the vegetation began to undergo tremendous growth. At this time, other landscape plants were added.
	After 1 year, the site had developed into a full wetland ecosystem. The vegetation had reached its full potential and wildlife began to call the Hayfield wetland their home.

The flow of the two Hayfield cells are combined underground and discharged into a pool/riffle system (known as HS EFF) which conveys the flows into a long-standing riparian corridor. The riparian corridor is located along the south side of the site and consists of mature cottonwoods, willows, elderberry and other various deciduous trees and shrubs.

Most facilities were built with the help of volunteers, including local Boy Scout troops, Luke Air Force, American Society of Civil Engineer's Younger Member Forum of Arizona, as well as many others.

A few picnic tables are located throughout the Hayfield Site. Visitors are encouraged to take advantage of the rare opportunity to sit near the water and enjoy the beauty of Arizona's riparian environment.

Riparian Trail:

The American Heritage Dictionary of the English Language, Fourth Edition defines riparian as "Of, on, or relating to the banks of a natural course of water." The riparian trail at the Hayfield Site offers visitors the opportunity to see this special type of ecosystem that is extremely rare in the Phoenix area. The trails lead through a serene and quiet environment, providing views of some of Arizona's prime riparian habitat.

The Tres Rios butterfly garden was created in cooperation with the Phoenix Office of Art and Culture and local artists Matt and Maria Salenger, together known as CoLab. This striking public art piece juxtaposes the human-built environment with nature, allowing visitors to appreciate the work that has been involved with building the wetland system while also appreciating the beauty of the plants and animals that make it their home. Visit the CoLab Website.