The sea of orange inside Syracuse University’s Carrier Dome on game days may soon flow like never before.

The university last month received a $1.35 million state grant to install a system to collect the rainwater that runs off the fabric roof of the Carrier Dome, the 49,262-seat arena where SU’s basketball, football and other teams play.

Approximately 880,000 of the 6.6 million gallons of water that pours off the Dome’s 7-acre roof each year will be captured by the system and stored in tanks hung from the bottom of the arena’s upper bleachers. During events at the Dome, the water will be used to flush the toilets and urinals in the building’s 16 public bathrooms.

Building codes require the water to be dyed to avoid confusion with drinking water, even though the water will only be used in toilets and urinals. So university officials are considering coloring the water orange, the school's official color since 1890.

“We’ve been joking, wouldn’t it be neat if we could color it orange?” said Eric Beattie, the university’s director of campus planning, design and construction. “There’s probably some room for discussion.”

Blue, which SU uses as an unofficial accent color, is also a possibility, he said.

The university wants the public to notice the water harvesting system, and orange-colored water in the Dome’s toilets and trough-style urinals would be hard to miss. Beattie said the project is intended as a demonstration of how such systems can conserve municipal water supplies and reduce the costly infiltration of rainwater into already overloaded wastewater treatment systems.

Water flowing off the Dome’s roof runs into a gutter that rings the entire bottom edge of the roof. The gutter is about 10 feet wide and heated in the winter to keep snow and ice from clogging things up. The Dome’s humongous roof also is heated, so that snow doesn’t weigh it down.

Thirty-six drains carry the water from the gutter into the city’s stormwater system. And because the city’s street drains are combined with its sewer system, all that rainwater winds up in Onondaga County’s wastewater treatment plants, where it is treated at great expense before being dumped into Onondaga Lake.

Just the facts:

• Each of the four 5,000-gallon tanks that will hold rainwater captured from the Carrier Dome’s roof will be about 8 feet in diameter and 10 feet long and weigh 42,000 pounds when full.

• The tanks will hold enough water to flush the Dome’s toilets and urinals during two major sporting events before they’ll need more rainwater.

• Enough rainwater and snowmelt runs off the Dome’s 7-acre roof each year to fill 10 Olympic-size swimming pools.

• The gutter that rings the bottom of the Dome’s roof is wide enough to hold a car.

Piping will be installed to carry the water from 12 of the roof drains into four 5,000-gallon tanks, or cisterns, which will hang above the Dome’s upper concourse. In total, the tanks will hold 20,000 gallons of water — more than enough for the 10,000 gallons that get flushed down the Dome’s toilets and urinals during a football game.

The grant from the state Environmental Facilities Corp. will pay for most of the $1.5 million cost of the project, which, besides the tanks and piping, will include a filtration and chlorination system. SU will pay the balance of the cost.

The water that will be captured by the system annually represents about 13 percent of the water that runs off the roof — or about enough to fill one-and-a-half Olympic-size swimming pools.

Beattie said the uncaptured water — as well as any overflow from the storage tanks — will continue to go into the city street drains. However, he said the university will look into collecting more of the water and using it to irrigate campus landscaping and to flush toilets in other SU buildings.

The project is the brainchild of Bruce Wanlass, principal engineer for C& S Engineers, which has worked with the county to upgrade its wastewater treatment plants and is designing the rainwater harvesting system for the Dome.

Wanlass said the idea occurred to him while he was attending an Orange basketball game in the Dome with his 7-year-old son, Luke, in 2011. His engineer’s eye noticed all the piping on the ceiling of one of the Dome’s men’s rooms. That got him thinking about the water the Dome uses during major events and how much water must run off the building’s roof.

“I said, hey, it would be a neat idea to collect the rainwater and use it in the bathrooms,” he said.

The next day at work, he mentioned the idea to C&S President John Trimble, who promptly made calls to Syracuse University. SU officials said they were interested.

The grant is one of the larger ones handed out by the Environmental Facilities Corp., under its green innovation program, said former Syracuse Mayor Matt Driscoll, who is president and CEO of the corporation.

The university will save only about $4,000 a year by purchasing 880,000 fewer gallons of water from the city. Driscoll said the real benefit is to the environment because it means less wastewater going into Onondaga Lake.

Onondaga County is under a federal court order to reduce the untreated sewage that spills into the lake during heavy rainstorms.

Other rainwater harvesting projects in Syracuse

Destiny USA: A rainwater harvesting system on the roof of the shopping mall's new wing collects 4 million gallons of rain annually for use in common area and tenant restrooms.

Oncenter: Installed in 2011, the green roof on the Onondaga County Convention Center features a waterproof membrane covered with low-growing succulent vegetation to retain and evaporate rainwater. Keeps 1 million gallons of rainwater from entering the county's wastewater treatment system.

Onondaga County War Memorial: Cistern system collects 400,000 gallons of rainwater annually from the arena's roof. Some of the water is used to make ice for Syracuse Crunch games.

Rosamond Gifford Zoo primate exhibit: A system that includes rain barrels and cisterns collects runoff from rooftops. Combined with a rain garden and porous pavement in the exhibit's courtyard, the system keeps 613,000 gallons of rainwater out of the city's storm drains.

The Gear Factory: A green roof on the five-story former factory building, now an artists' studio warehouse, manages 226,000 gallons of rainwater annually.

Contact Rick Moriarty at rmoriarty@syracuse.com or (315) 470-3148. Follow him on Twitter @RickMoriartyCNY and on Facebook at rick.moriarty.92.