The appearance and size of Frick Park will be dramatically changed with the restoration of Nine Mile Run, long a conduit for storm water and sewage flowing to the Monongahela River.

Even birds and damselflies will notice the changes, conservationist Marijke Hecht, executive director of Nine Mile Run Watershed Association, said yesterday.

The $7.7 million project will alter the flow of the stream and two tributaries, nurture a new aquatic ecosystem and add 100 acres to the park, bringing it to 550 acres. It's urban renewal of a highly unusual kind.

"It's actually one of the largest urban stream restoration projects we have in the United States," Hecht said while giving a tour of the project site to about 20 association members and curious park visitors.

Hecht said Meadville Land Services in Crawford County will install sweeping curves, pools and riffles to slow the water that sometimes damages stream banks when it cascades into Nine Mile Run from East End communities.

She said the riffles will oxygenate the water and help make the stream, now virtually lifeless, more inviting to various kinds of fish and invertebrates.

Hecht said the company's work, to begin this spring and take more than a year, also will transform three fields into wetlands with wildflowers and other plants. She said the wetlands should draw birds, butterflies and damselflies.

The project was lauded by those on the tour.

"It's good for nature," said Jerome Garrett, a Wilkinsburg School Board member.

"I'm tickled pink with it. It's long overdue," said Squirrel Hill resident Jack E. Solomon, president of Three Rivers Birding Club.

As a boy, he said, he played in other area streams but avoided malodorous Nine Mile Run. In recognition of the sewage contamination, he said, kids then and today use a profane shorthand name for the stream.

While the restoration will address the stream's physical problems, other challenges remain. Hecht said there's no easy way to stop sewage and other pollutants from entering the stream.

But her group has encouraged East End communities to convert vacant lots to green space to slow and cleanse the water flowing into Nine Mile Run. Also, she's trying to raise awareness of the pollution caused by road salt and motor oil.

Nine Mile Run, named for its distance from The Point, absorbs water from rooftops, driveways, parking lots, hills, drains and sewers in the 6.5-square-mile watershed.

Hecht said the stream and countless tributaries flow underground perhaps for 20 miles before Nine Mile Run hits daylight at Braddock Avenue, near the border of Edgewood, Swissvale and Pittsburgh.

From there, depending on the amount of rainfall or melting snow, the water trickles, flows or cascades 2 miles through Frick Park and the upscale housing development called Summerset at Frick Park. The stream then empties into the Mon at Duck Hollow, near Swisshelm Park.

The housing development, partially visible from the Parkway East, is built on a 250-acre slag dump. As part of the stream restoration, Hecht said, the city will acquire 100 acres of slag dump, add it to the park and provide access to the Mon.

The U.S. Army Corps of Engineers will manage the restoration, funded with $5 million in federal money and $2.7 million raised by the city. Pittsburgh work crews already have reduced the size of a parking lot and done other work to prepare for the restoration.

Hecht said water sometimes reaches Nine Mile Run with such force that it erodes stream banks and cuts a wide, shallow swathe through the park. In the dryness and heat of late summer, the stream shrivels into isolated pools that do not support aquatic life.

She said the restoration work will improve the stream's appearance and better harness the water's potential as a habitat.

New curves, 15-foot-deep pools and riffles will create a kind of obstacle course for hard-running water, while new trees and plants along the banks will help to prevent erosion. During dry spells, Hecht said, the wetlands will replenish the stream.

The stream will be pulled deeper into Frick Park and given a new confluence with two tributaries, Falls Ravine and Fern Hollow.

The tributaries themselves will be improved. Their courses will be altered, Hecht said, and sections flowing below ground will be brought to the surface.