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Landscaping collects, processes, and filters runoff from impervious areas and trackways to ensure no stormwater leaves the site of TriMet's new light rail terminus. Photo: Ambient Light

The stimulus package is also expected to fund 22 vertical-axis wind turbines on top of the screen's outer perimeter poles to support the electrification wires that power the trains. This will be done through a separate application to be processed after final granting of the funds for the photovoltaic system.

The savoniuos-style turbines, designed and made by Portland-based Oregon Wind, can produce energy even at wind speeds of a little more than 2 mph. Expected to be installed by February 2010, they'll provide valuable insight into the effectiveness of wind energy in an urban environment.

Altogether, these technologies are expected to provide almost 100% of the power consumed onsite by technical equipment and lighting.

In addition to minimizing reliance on manmade electricity, TriMet took pains to ensure terminus operations don't increase the chances of an illegal discharge from the city's combined sewer system into the Willamette River, which runs through the center of the city.

The site plan revolves around a large ovoid public open space, topped with pervious pavers, and the trackway configuration; and is designed to retain and filter virtually all stormwater.

Most runoff is channeled into a slightly depressed stormwater infiltration planter. The turnaround itself is composed of interlocking pervious concrete pavers allowing infiltration of stormwater into the soil below.

The ovoid, which accommodates the required fire apparatus turnaround, is surrounded by a cast-in-place concrete perimeter restraining ring that forms the outline of the ovoid while serving as a transition between asphalt surfaces and the pavers.

The safety and security of both TriMet maintenance employees and the public were also integrated into the design strategy.

The perimeter and form of the terraced edges of the landscaped stormwater disposal planting area are defined by a subtle grade transition that discourages pedestrians from entering active rail areas. Benches along the south edge of the plaza, made of granite curbs reclaimed from the original mall, contain integrated LED indicator lights and custom engravings demonstrating the amount of energy produced onsite at any moment.

The construction of the South Terminus improvements was folded into a construction management/general contractor (CMGC) contract already under way for the balance of the mall renovation. Cost estimating was provided by TriMet engineering staff with supporting information from Stacy and Witbeck/Kiewit Pacific, the project's construction manager/general contractor.

TriMet plans to incorporate renewable energy components into future light rail transit expansion projects.

— Eddy (teddy@henneberyeddy.com) is a LEED-accredited architect and a founding partner of Hennebery Eddy Architects Inc. in Portland, Ore.