Sometime in the next quarter century, a giant new island will rise someplace in the upper Bay to hold millions of cubic yards of silt and sand dredged from shipping channels in Maryland's portion of the Bay.

The giant, new, artificial island is a key element of a new, long-term dredging plan to maintain shipping routes to the Port of Baltimore.

At the same time, the plan rules out disposing of dredged materials in the "deep trough," which has long been opposed by watermen and environmentalists. And, if implemented as written, the plan would end the controversial but low-cost "open water" placement of dredged materials in Maryland's portion of the Bay within a decade.

The plan, unveiled in September by Gov. Parris Glendening, is aimed at assuring major shippers - several of whom are making decisions about where to do business in the future - that the state has a strategy to maintain shipping channels for at least 20 years. "This plan, a comprehensive, multiagency effort, is environmentally sound, fiscally responsible and geographically balanced," Glendening said.

The plan is the state's attempt to balance the needs of the Port of Baltimore - which generates $2 billion of annual economic activity - with the needs of the Bay, its most valuable natural resource.

Each year, about 5.3 million cubic yards of sediment must be dredged from channels to maintain adequate depth for ships using the port. That's enough material to cover a football field nearly 3,000 feet deep - more than half a mile.

In some of the coming years, though, as much as 11 million cubic yards (enough to cover a football field more than a mile deep) must be dredged both to maintain existing channels and to deepen and improve shipping lanes and anchorages to accommodate the ever-larger ships being used in international trade.

To meet those dredging needs, the plan includes six placement options:

  • Expand the open water placement area near Pooles Island in the upper Bay for use until 2000, to hold an additional 4.5 million cubic yards. The cost to the state is 20 cents per cubic yard.

  • Raise the dikes on a portion of Hart-Miller Island in the upper Bay to hold an additional 30 million cubic yards over the next 12 years. The cost to the state is $1.50 per cubic yard.

  • Restore Poplar Island in the mid-Bay to create 1,110 acres of habitat with 38 million cubic yards of dredged material over the next 20 years. The cost to the state is $5 per cubic yard.

  • Reactivate the CSX/Cox Creek containment site adjacent to Baltimore Harbor so it will hold 6 million cubic yards over the next 12 years. The cost to the state is $2.50 per cubic yard.

  • Create a new, open water placement site, at a location to be determined, which will hold 18 million cubic yards over the next nine years. The cost to the state is less than $1 per cubic yard.

  • Build an artificial island in the Bay north of the Bay Bridge, which would hold 50 million -100 million cubic yards over the next quarter century. Cost to the state would be $1.50 per cubic yard.

The plan closes the door to placing dredged material in the deep trough, which has been proposed from time to time as a low-cost placement option.

Whether placing materials in the deep trough would have a significant environmental impact has long been debated, but resource agencies, environmentalists and watermen have long opposed the option saying it would impact habitat for species that winter in the 140-foot-deep trough south of the Bay Bridge.

They also argue that nutrients in the sediment could be drawn out by the low-oxygen conditions that exist in the trough throughout the summer, and that natural seeps in the trough would resuspend the sediment into the water column.

Although not explicitly ruling out further open water placement, the plan contains no open water discharge sites after the year 2006.

"It would be short-sighted and irresponsible to sacrifice the long-term health of the Chesapeake Bay," Glendening said of the deep trough option.

The new plan also states, for the first time, the state's commitment to the full 1,110-acre Poplar Island restoration project. Earlier versions had included only the first 640-acre phase of the project.

The Poplar Island project is aimed at restoring a mid-Bay island that has largely eroded away in the past two centuries. The project - half of which would be uplands and half wetlands - is intended to provide new habitat for a variety of birds, fish, shellfish and other species. The federal government is paying about 75 percent of the restoration costs.

The project is widely supported by environmentalists, watermen and resource agencies. But many officials have argued that its $400 million tag means it must be balanced with other low-cost disposal options.

The new, unnamed island proposed for the upper Bay differs from the Poplar Island restoration in that it is primarily aimed at holding a huge mound of dredged material rather than creating a wetland complex that benefits Bay species. Sometime in the future, though, it is possible that parts of the artificial island may be designed to provide some habitat benefits.

Still, the creation of the new island is seen by many as a preferable alternative to continued open water placement. Because material could be stacked high above water level, the island would affect a much smaller portion of the Bay than spreading the same amount of material directly into the water.

While not as cheap as open water placement, creating the island costs less than many other options. But, cautioned Frank Hamons, manager for harbor development with the Maryland Port Administration, "if you don't get some of the other options that are listed here, it would put us in a situation where we would have to find something to replace that missing option."

The Chesapeake Bay Foundation supported the plan as the "lesser of two evils," said Bill Goldsborough, a CBF scientist. "The way we look at the situation, the port is too important to the state not to do the dredging necessary to maintain the navigation channels, and there is no perfect solution for accomplishing that and avoiding all environmental impact to the Bay." While the plan sets out a framework for minimizing those impacts, Goldsborough cautioned that "there's a lot in that plan that's really undecided at this point."

For example, the plan does not specifically say where a new containment island would be built, or what areas would be used for additional open water placement of dredged materials, Goldsborough said. "There are a lot of environmental trade-offs that go with those choices, so we need to continue to be involved."

To mitigate dredging impacts, Glendening announced a plan to pay up to $18 million over six years to support oyster restoration projects in the Bay.