The Bay Program has committed to preserving 20 percent of the watershed as permanently protected open space by 2010. In January, it plans to release its first estimate of how much ground it has to cover with easements — or buy — to reach that goal.

After hammering out a general definition of what is considered “permanently preserved,” each state in December was finalizing estimates of how much land was already protected either by public agencies or private land trusts.

To meet the goal, part of the Chesapeake 2000 Agreement, about 7.7 million acres must be protected. Preliminary estimates indicate the Bay states will be about 1 million acres short, meaning they would need to protect roughly 100,000 acres a year during the coming decade.

The upcoming report will not list individual properties, but will present preserved acreage by category, such as state parks, lands in farm preservation programs and so on. “We want to provide the opportunity to comment on anything that needs refinement or explanation,” said Bill Matuszeski, director of the EPA’s Bay Program Office.

The process has already drawn some criticism because of how the numbers were derived. Lee Epstein, of the Chesapeake Bay Foundation, said the states did an “excellent” job collecting the data, but faulted the Bay Program for not having more specific and uniform criteria among states for counting preserved land. For example, he said, states appear to have different standards for counting historical sites, some of which may have little open space value.

The biggest disparity is with Department of Defense lands. Virginia is counting forested and other open portions of military bases — much of which is used for hunting and other recreational purposes — toward the goal. Both Maryland and Pennsylvania opted not to do so.

What could boost “preserved” acreage in Virginia — and reduce the watershedwide gap — by about 150,000 acres. But the Defense Department has raised concerns about the classification because the law requires that military lands must be available for national security purposes — from military housing to firing ranges — or risk being declared surplus and discarded.

“Our view has been that the Department of Defense land is owned and operated by the U.S. government for national security purposes, not for open space and natural resource protection,” Epstein said. “Since they have the ability to change that use by disposing of that land whenever they feel like it, our view up until this point is you really can’t count Department of Defense property as permanently protected open space.”

Under a compromise worked out among federal and state officials, Virginia was allowed to count the acreage as long as it remains open space. If the Defense Department changes the land use or opted to discard the land, the state would be expected to make up the loss. Gary Waugh, a spokesman for the Virginia Department of Conservation and Recreation, said state officials anticipate the military bases will remain undeveloped into the future, and that the state would likely protect them if the bases were ever closed.

“If those lands were surplused by the federal government, the state of Virginia would certainly be the first people they would approach,” Waugh said. “We would have the opportunity to look at those lands for possible acquisition.”

The Bay Program has yet to develop any strategy for preserving an additional 1 million acres of land. Officials say that while they do not expect preservation goals to be given to individual states, some method is needed to track progress.

Meanwhile, the Chesapeake Bay Commission at its January meeting is to receive a report from the Trust for Public Lands, a nationwide nonprofit group, outlining potential strategies that would help to meet the goal. A preliminary estimate by the trust indicated the Bay states would need about $500 million over the next decade beyond recent land protection funding levels to meet the preservation objective.

“A million acres will be a huge challenge,” said Ann Swanson, executive director of the commission, an advisory panel representing the state legislatures.

Lands Definition

“Land that is permanently protected from development with a perpetual conservation or open space easement or fee ownership, held by a federal, state, or local government or nonprofit organization for natural resource, forestry, agriculture, wildlife, recreation, historic, cultural, or open space use, or to sustain water quality and living resource values.”