The Arizona Cardinals kick off their 2006 season with the
completion of one of the largest Arizona construction projects in
the past two decades - the University of Phoenix Stadium. The
$455 million stadium in Glendale has a 13.3-acre domed-roof
made of two retractable panels that opens the football field and
stadium seats to the Arizona sky. The feature contributing most
to the multipurpose capability of the stadium is the retractable
field, the first of its kind in North America.
The parking lot holds 14,500 cars, and additional parking is
provided off-site immediately adjacent to the stadium property.
Runoff from the roof and parking area runs into four 24-inch
storm drains that flow from the building site and into the nearby
Bethany Home Outfall Channel.
State regulations called for controlling runoff from the 206-foot high roof and the asphalt before it flows off-site into the abutting drainage channel. Thirteen Vortechs systems from Contech are found at 10 points around the property and clean the runoff before it enters the channel. An underground alternative was preferred to creating a 14-acre detention pond to hold site runoff because a pond used too much valuable real estate. Treating the runoff with underground BMPs was much more economical than the pond.
Because releasing stormwater flows directly into a channel is unusual in Arizona, developers needed to provide proof to the city that the stadium runoff wouldn’t affect the channel during a 100-year storm. They mathematically showed that any stadium runoff would be discharged before the rest of the runoff from the dozen square miles of drainage area arrived.
By combining Vortechs systems with the grassy strip bordering the channel, developers provided the most cost-effective alternative to meet state needs. The Vortechs models used are: two 11000s, four 16000s and seven PC1319s, the three largest precast systems Contech manufactures, for a total of 13 units.