Development Speeds Shrinking Changes to Western Pennsylvania
20 July 2013
By Aaron Aupperlee
Pittsburgh Tribune-Review Staff Reporter Aaron Aupperlee can be
reached at 412-320-7986
Members of the Golden Triangle Water Ski Club depend on Nine Mile
Island to break up the choppiness of the Allegheny River and
create a smooth channel for runs down their slalom course.
But the island, acquired by the club in 2001, is shrinking.
“Our poor island is disappearing rapidly,” said Jack Hoffman, the
club's president. “We're really unhappy that it's going down the
tubes, but there's nothing we can do about it.”
In Western Pennsylvania, the Allegheny and Ohio rivers are home to
dozens of islands. Rising and falling water levels, shifting
currents and changing river bottoms naturally cause river islands
to shrink, grow or move, said Helen Delano, a senior geologic
scientist with the Pennsylvania Geological Survey.
Development along the shores of the rivers and changes to
accommodate shipping speed up the snail-like pace of geological
In the Ohio, an Army Corps of Engineers project starting in
September could stop erosion of Georgetown and Phillis islands,
about 35 miles from Pittsburgh. They are part of the Ohio River
Island National Wildlife Refuge.
Nearly all of the refuge's 22 islands are shrinking, said Deputy
Manager Sara Siekierski. In the past 50 years, Georgetown Island
shrank from 17 acres to 5. Phillis Island went from 26 acres to
The project will build dikes around the islands and along the
shipping channel, said Army Corps spokeswoman Sheila Tunney. The
Corps will dump tons of sediment behind the dikes, using material
dug up during annual dredging work. It typically pays $45 a ton to
haul the sediment to a landfill. Over five years, the agency could
save up to $600,000 by using it on the islands instead, Tunney
No such plans are in the works on the Allegheny, Tunney said.
Nine Mile Island, near Blawnox, was once about 20 acres, said
Charles Bier, the Western Pennsylvania Conservancy's senior
director for conservation science. The conservancy took ownership
of the island in 1971. When the organization transferred it to the
water ski club in 2001, about 5 acres remained above water, Bier
“As we've taken some of the sand and gravel out of the river, the
speculation is that by changing the configuration of the bottom of
the river, you change the pattern of the flows. Those flows can
eat away at the islands,” Bier said.
The shrinking islands threaten the habitat of several species of
endangered fresh-water mussels, Bier said. Some islands serve as
nesting grounds for bald eagles and great blue herons. Siekierski
hopes work in the Ohio will make its islands more attractive to
fish, mussels and other species.
Historical photographs show that as Nine Mile Island shrank,
neighboring Sycamore Island grew. Over the past 200 years, the
island has grown from about 8 acres to 14, said Chris Beichner,
executive director of the Allegheny Land Trust, which owns the
A slow current around the island has allowed sediment to build up,
Upstream, islands making up Allegheny River Islands State Park
also have grown, said Matt Greene, the park's director.
Golden Triangle Water Ski Club members don't see a reversal of
fortune in the future of their island.
Joe Deltondo, a club member for about 40 years, said he has
watched shrinking conditions force the club to tear down a
concrete building about to plunge into the river and move a picnic
“We've lost half of it since then,” Deltondo, 84, of Blawnox said
of the island.
Aaron Aupperlee is a staff writer for Trib Total Media. He can be
reached at 412-320-7986 or firstname.lastname@example.org