SILVER SPRING - The Good Hope tributary is a tiny stream through the woods of Montgomery County - no more than a few feet wide. In many spots, a reasonably healthy adult could jump over it with little effort.
But for Gov. Robert L. Ehrlich Jr. and all the other officials who have wanted to build the Intercounty Connector in recent decades, the stream has been as formidable a barrier as the mighty Mississippi. Its clear water feeds the famed Paint Branch, the only place in the Washington metropolitan area where brown trout spawn in the wild.
Now, for the third time in the past 22 years, the federal Environmental Protection Agency is pointing to the proposed crossing of the Paint Branch watershed as one of the leading reasons it objects to the route most often discussed for a highway that would link Rockville and Laurel.
The so-called Corridor 1 route is favored by many Montgomery County business and political leaders because it displaces fewer homes and businesses than a northern alternative. But precisely because it would run through undeveloped areas, the environmental costs would be greater.
It "bisects major stream valley parks" and "crosses high quality wetlands embedded in interior forest," the EPA said in a letter to the state outlining its objections to Corridor 1.
John Parrish, a local activist who opposes the highway, describes the environmental risk in simpler terms.
"If you look at the water here, it's crystal clear," he says. He is gesturing to a trickle, called a seep, that comes from a nearby wetland and dribbles into the Good Hope. The clarity helps to explain why the trout thrive.
The Ehrlich administration - which argues the highway is vital to relieving traffic congestion and improving the state's economy - told the EPA it thinks Corridor 1 could be made environmentally palatable by adopting a package of "stewardship" measures to mitigate damage.
Among other things, the administration promised to build longer bridges to avoid having to fill in sensitive areas. It also said it would improve storm-water systems and create new wetlands.
But in its reply, the EPA said it still objects to Corridor 1. It has concerns about the other route, too.
A recent tour of the ICC's path with environmentalists who oppose the road offered a ground-level view of some of the obstacles the administration will have to overcome as it seeks federal approval for the ICC, especially if it chooses the southern corridor.
Environmentalists have been giving these tours for years for anyone willing to put on a pair of boots and take a hike in the woods. One stop is the Good Hope tributary.
Paint Branch watershed
Corridor 1 would run through a swath of woods about 400 feet wide bordering Dr. Charles R. Drew Elementary School.
"All these kids are going to be exposed to pollution," Jim Fary, chairman of the Montgomery County Sierra Club's conservation committee, says as he enters the woods, where ribbons on the trees mark the survey work of state highway crews.
Fary and Parrish are leading a reporter and photographer on an ICC tour. It is not an objective presentation, any more than was a recent tour led by the governor promoting the merits of the proposed highway. Fary and Parrish do it to make their case against the ICC, raising some of the same points mentioned by the EPA.
Parrish talks about the bird species that could be harmed if the woods are cut down. The pileated woodpecker and barred owl, he says, breed in the interior of a forest, not on the edge. If the forest is too fragmented, he says, the species lose its habitat.
The Good Hope may be small, but it's not silent. Visitors can hear its waters rippling over the rocks as they approach it.
Parrish, vice president of the Maryland Native Plant Society, says the key to the Good Hope's success as a trout spawning stream is its coolness even in summer. Young trout can't bear temperatures much above 68 degrees, but the Good Hope is fed with cool water from surrounding wetlands and protected by forest cover up to its banks, he says.
Parrish says the stream is under constant stress, however.
"The trout fishery is near the edge of its tolerance for siltation, for stream temperatures and things like that," he says. "The ICC would be the final nail in the coffin for this thing."
State Highway Administrator Neil J. Pedersen said in a recent interview that his agency has brought in experts to craft strategies to minimize the impact the ICC would have on the fish population.
"There are no guarantees about anything, but we are reasonably confident we will be able to develop a mitigation strategy that would ensure the continued viability of the brown trout," he said.
So far, the EPA is not convinced. In its recent critique, the agency said Corridor 1 poses a "considerable risk that the trout population will be lost" because of added sediment, forest clearing and the potential failure of filter systems.
Northwest Branch wetlands
Northwest Branch, near the midpoint of the ICC, is not in the class of Paint Branch when it comes to water quality. Stocked trout can survive here but cannot spawn. The stream banks are seriously eroded.
But at the point where Corridor 1 crosses it, Northwest Branch is surrounded by 40 acres of what the EPA calls "the most intact highly functioning wetlands available."
At the edge of a small pool, Parrish spots a skunk cabbage, one of the first plants to flower in the late winter. It is one of about 100 plant species that flourish in the wetland, he says.
The state is proposing to mitigate any damage to existing wetlands by creating new ones nearby. But Parrish says a manmade wetland would support far fewer species.
"This is a biodiverse wetland. It has turtles, frogs, salamanders and a diverse flora," Parrish says. "You cannot replicate the kind of diversity in a wetland like this."
The EPA credits state engineers with being "generous" in their proposal to soften the impact on the wetlands by bridging over them. But the agency said Corridor 1 would still damage the wetlands.
There are hundreds of trees in the forest off Pinetree Road in Rockville, but one of them stands out like a boilermaker among ballerinas.
It's known simply as "The Big Tree" - a knobby, gnarled tulip poplar so bulky it would probably take six tree-huggers to encircle it. For some reason, it was spared when its nearby contemporaries were cut down.
"I feel comfortable that it's 250 years of age. It could be older," Parrish says.
If the ICC is built, no matter which route is chosen, The Big Tree will likely become lumber. It is part of a forest that stands in the highway's path west of the point where Corridor 1 and the northern alternative merge.
Parrish says The Big Tree is one of 10 county champion trees - the largest of their species in Montgomery - that stand in the path of ICC Corridor 1.
Pedersen, the SHA administrator, said he's familiar with The Big Tree. He said there's been some discussion among planners about whether it would be possible to change the alignment to avoid it. But at that point in the route, there isn't much right of way to spare.
"I suspect it probably still has to come down," Pedersen said.
Rock Creek park
Far from the nearest road, at a point accessible only by a deer trail, Parrish kneels by a low-lying area of standing water deep in the woods.
"This is a vernal pool and it's critical breeding habitat for a number of amphibians," he says. If the ICC comes through the park at this point, he says, the pool will be filled in.
Among the species that breed only in such pools, he says, are the spotted salamander, marbled salamander and wood frog.
"They're very scarce," Parrish says. "They can't cross a highway. They get smooshed."
The group is gathered near the confluence of Rock Creek and Mill Creek, in the path of what is known as Rock Creek Option A - one of two alternatives identified by highway planners for crossing Rock Creek Regional Park.
Rock Creek A goes through the heart of the park, Fary says. The other option under consideration, called Rock Creek C, requires the seizure of 14 more homes than Option A.
"It kind of pits park versus community," Fary says.
The road builder
Some supporters of the ICC have no interest in getting out of their cars to see what they propose to pave to build the highway.
Not Pedersen. He has been walking the proposed path of the ICC for about 25 years, sometimes in the company of its opponents.
Pedersen says he has tried to understand the issues from their perspective and incorporate their concerns into the plans for the highway. He says he considers himself an environmentalist and knows some sensitive areas would have to be sacrificed to build the ICC.
But Pedersen says building the ICC is a must. The local roads that connect Interstate 270 and Interstate 95 cannot handle today's traffic volumes, he says, much less those expected in the future.
"Our business is such that it involves trade-offs. There is no such thing as an impact-free highway," he says. "Ultimately we need to look at the trade-offs and make a decision."