Official Web Site of the City of Phoenix

The Cobble Site, as designed in 1995, consists of two elongated cells located within the Salt River Flood way.

	At the time of planting, workers planted the bulrush approximately 3 feet apart.
	When the water was turned on, the vegetation quickly began to sprout.
	With a high success rate, the vegetation quickly created a fully functional wetland ecosystem.

The design of the Cobble Site was originally configured to have a mix of both deep zones and emergent areas. The 3 deep zones together comprised roughly 20% of their surface area. The design of the deep zones provides a multitude of benefits:

1. they allow remixing of waters after they pass through a shallow, vegetated emergent zone where short-circuiting is likely to occur (short-circuiting is a process where water moves through a system without having adequate contact with enough vegetation to cleanse it of its impurities),
2. they tend to enhance the habitat value for waterfowl by giving adequate open water surface area away from vegetation where predators could be hiding, and
3. the can alter the water chemistry because they will have an aerobic water column and an anoxic bottom layer (both important from the standpoint of nutrient transformations, metals attenuation and decomposition of organic compounds).

Recent research has focused on security for the site. Vandalism has caused the south basin to be dry since January 2004, causing an important ecosystem to die. For this reason, the City respectfully asks that the public not visit this site. Rather, the Hayfield Site is specifically designed for visitors and is a great location for tours.

Please contact us for more information.