Montgomery County's crummiest stream winds through the upscale, country club neighborhoods of Bethesda and Chevy Chase, the quaint village of Somerset and blocky high-rises in Friendship Heights.

What's left of Little Falls Branch follows a strip of forest south of Massachusetts Avenue, wandering a bloated channel where once-buried sewer pipes lay exposed and nearly all stream life is gone. Its tributaries have been obliterated, stripped and armored into concrete ditches that wear bottom coats of stringy algae.

Little Falls Branch was sacrificed decades ago so that suburban neighborhoods could take root in Montgomery's forests and farmland. It's a typical tale, reflecting the fact that most of the country's waterways in cities and suburbs have long been used as convenient gutters.

In recent years, government officials and scientists have been trying to write a happy ending to that story in Montgomery. A recent, computer-mapped county study has comprehensively catalogued the health of the county's 1,500 miles of streams. Thirty-five percent of these streams are in fair or poor condition--not a surprising number, say the experts, given Montgomery's surging population growth after World War II.

In its efforts to comply with federal and state antipollution laws, Montgomery has scored some successes that have won it national recognition. But protecting and restoring streams is a tough and costly job that requires large doses of political will. As the task becomes clearer, county officials have returned again to the issue of whether they should create a utility tax, requiring residents to pay millions of dollars more each year for stream management.

Using a stopgap approach won't resolve a problem of this magnitude, said County Council President Isiah Leggett (D-At Large). "We're doing better than most jurisdictions," he said, "but I don't think it's enough."

An important catch

As a strong breeze swooped off the surrounding hills near Clarksburg, county employee Doug Marshall found what he was looking for beneath a dripping rock pulled from Little Seneca Creek. His catch wasn't much larger than a speck in his palm.

"These guys need to have cool temperatures, and they need oxygenated water. They have external gills," said aquatic biologist Marshall, fingering the larva of a water-dwelling insect called the stonefly.

Marshall regards this tiny larva as a sentinel for trim, soft-shouldered Little Seneca Creek. One of the county's best streams, Little Seneca lies close to Clarksburg in northwest Montgomery. When construction begins in the coming months to transform Clarksburg's stubbly hayfields into a new town center, county biologists will watch what happens to the creatures of Little Seneca.

Using bugs and the fish that eat them to diagnose streams is called biological monitoring, and Montgomery is among the first localities in the country to employ this technique.

Last year, Montgomery officials published their stream monitoring results, along with land-use conditions for the county's 22 watersheds, in a computer-mapped document called the Countywide Stream Protection Strategy (CSPS). It showed, predictably, that Montgomery's best streams are located upcounty in the predominantly agricultural area and near large parks, while the poorest streams are found downcounty in densely populated communities built decades ago.

Laws such as the federal Clean Water Act recognize the importance of streams' natural functions in feeding rivers, replenishing ground water and, in this region, supplying the freshwater tap for the Chesapeake Bay.

Biological monitoring reveals stream health because the inhabitants of a stream have to deal with everything that flows past them, explained Keith Van Ness, the county's senior ecologist. They survive or they die.

A wide array of fish and insects inhabits stream pools and rocky shallows in this piedmont region of rolling, forested land and clay-rich soils. In the spring, county biologists don chest-high waders to turn over rocks in the channel and identify water-dwelling insects. In the summer and early fall, they go back out again, to net and identify fish and jot notes about stream and floodplain conditions. In the current five-year study cycle that concludes in 2001, county biologists will have visited an estimated 300 sampling locations. They publish their findings online-- they update the stream protection plan.

Degraded streams lose their diversity. For example, Little Falls Branch and its tributaries are home to five species of fish. In contrast, Little Seneca Creek and its tributaries have 29 fish species. The Environmental Protection Agency is promoting the idea that measuring biological capacity, rather than just analyzing water chemistry, provides a broader picture of stream conditions.

"When I go out and talk as an EPA official, I point to Montgomery County as an outstanding example," said Bill Swietlik, one of the agency's experts on biological monitoring.

State environmental officials, swayed by Montgomery's case for biological monitoring, now require that Maryland's nine big counties and the city of Baltimore use the technique to help evaluate their streams. Montgomery is the only one of those counties--which include Anne Arundel, Howard and Prince George's--that employs biological monitoring on all its streams.

Fairfax County borrowed heavily from Montgomery in inaugurating the first biological stream monitoring program in Virginia this spring.

Although Montgomery's efforts now are praised, the county was in trouble with state officials in the early 1990s as it fell far behind in the legally mandated monitoring of streams. State officials expected the county to follow the usual method of chemically analyzing water samples. But in pressing for the biological approach, the county said everybody knows the pollutant that is destroying Montgomery's streams. It's plain dirt.

How a Stream Is Hurt

A stream under stress thrashes in its channel like an injured animal. The coursing water eats banks raw, undercuts sheltering trees and digs the stream bed below the surrounding floodplain. Distinctive features such as shallow, gravelly bottoms and still pools that can harbor creatures are coated with suffocating silt.

These ruinous flushes occur whenever it rains, with water from parking lots and sidewalks, rooftops and city streets, anywhere the ground has been replaced with a hard or impervious surface that does not allow water to soak into the soil. The storm water disappears down storm drains, into underground pipes and then into streams. Waterways are engorged during rains, then starved during drought, when there's too little ground water to seep into the channel and sustain the stream.

Experts have calculated that a stream begins to suffer when more than 10 percent of the watershed--the land that drains into the waterway--becomes impervious. In the older neighborhoods of Montgomery, some streams have watersheds where more than 35 percent of the land has been hardened into driveways, sidewalks and buildings. Single-family residential properties, not mall parking lots, are the biggest source of runoff. They constitute half of the county's total impervious area.

In 1971, the county established storm water controls for new development, but the techniques were poorly engineered and often ineffective until the mid-1980s. Now it's estimated that about 25 percent of the more than 327,000 housing units in Montgomery have adequate controls, usually constructed ponds that gradually release storm water and prevent damaging surges.

As engineering improved, county officials considered how to undo stream damage from earlier decades. They knew more than just fish and bugs suffered--badly eroded streams also claimed the back yards of anxious taxpayers. In one case, the county spent $1 million in 1995 to install a mile of stone riprap along Sycamore Creek in the Aspen Hill area.

In 1993, officials wanted to begin reclaiming Little Falls Branch by building three large storm water ponds on parkland. The idea wilted when it hit intense opposition from Bethesda and Chevy Chase residents incensed over the planned removal of trees.

But storm water ponds are the centerpiece of Sligo Creek's $2.5 million revival on the eastern side of the county. Off Dennis Avenue, three large, ungainly ponds, their shorn banks flecked with storm-driven debris, hold runoff from 800 acres of downtown Wheaton. The ponds, excavated in 1990, slow down torrents of creek flow and allow dirt to settle out.

After the ponds were dug, officials restored features to the 12-mile-long creek: They replanted and regraded banks, arranged boulders and logs in the stream bed for a meandering flow and reintroduced native fish species.

"We've taken Sligo from three pollution-tolerant [fish] species to 11 naturally reproducing fish species in the stream," said Pamela Rowe, a watershed planner and a principal author of the county's stream strategy. The Sligo restoration has been praised as a national model by the Natural Resources Defense Council in a new report on storm water programs.

Officials hope that in upcounty Clarksburg, they can keep problems like Sligo's from occurring. To protect Little Seneca and Ten Mile Creek, town center developer Clarksburg Land Associates LP must stay farther back from stream banks, limit hard surfaces such as concrete and asphalt, and install storm water facilities that will detain and release runoff repeatedly before it reaches the creeks. The developer and the county will monitor the creeks as Clarksburg grows to a projected 30,000 over 20 years.

Making development a good neighbor on land that drains into Paint Branch has its own set of complications. This eastern county stream is unusual for harboring brown trout, a pollution-sensitive fish, even as development claims bigger chunks of its watershed. To protect fragile Paint Branch tributaries east of Cloverly, the county has committed more than $13 million since 1996 to buying 350 acres for stream buffers. The county wants to buy another 100 acres in the area over the next few years, bringing the total expenditure to an estimated $17 million.

County Executive Douglas M. Duncan (D), jolted by the price tag when his staff proposed the land purchases in 1995, pushed environmental officials to tell him what other watersheds needed big fixes. Their response produced the stream protection study, which prompted Duncan last year to increase from $15 million to $20 million the county's six-year budget for building storm water ponds and restoring streams.

The study, Duncan said, helped him to better understand the complexities of stream management. "Now I'm confident the money we're spending is making a difference," he said.

Cost of Restoration

Even so, watershed protection is a small slice of the county pie chart. The $20 million for storm water ponds and restoring streams comes out of a current six-year capital improvements budget of $734 million, and it represents about 3 percent of the capital budget.

"I have enough money to have a very proactive program," said Cameron Wiegand, watershed management chief. But the county's own study shows the magnitude of the task. Watersheds covering a third of the county have streams bearing the telltale signs of stress--channel instability, acute erosion, heavy silt loads. The handful of watersheds scheduled for the next round of restoration includes Little Falls, Upper Paint Branch, Northwest Branch and Rock Creek.

National storm water expert Tom Schueler estimated that tackling more of the restoration work could annually cost the county $10 million--three times what it now spends.

"The county political leadership knows it's going to be expensive, and people are afraid of that," said Neal Fitzpatrick, conservation director for the Audubon Naturalist Society, which has pushed the county for better stream management.

Making sure storm water facilities work is another long-neglected and expensive job, but one the county must shoulder to comply with federal and state laws. Countywide there are 2,300 facilities, many of them constructed ponds or underground concrete storage chambers.

Five hundred belong to the county, but the rest are privately owned. The county's ongoing, first-ever facility inspection, started in 1998, has found so far that 97 percent need maintenance.

Annually inspecting and maintaining these facilities could cost $8 million to $10 million, said Ellen Scavia, chief of the county's environmental policy and compliance division. That estimate prompted an ongoing staff study on whether the county should create a storm water utility tax or user fee system, similar to programs in Prince George's and Prince William counties. A similar Montgomery staff effort in 1996 produced no conclusions.

The current work group, which likely will report to the county executive and council in the coming months, hasn't yet determined how a tax or user fee should be structured, nor how much money should be raised.

There is agreement in the work group, said Scavia, that county inspection and maintenance of storm water facilities is a basic public service. Duncan declined to say whether he favors a new tax or user fee.

Leggett, who is chairman of a key council committee for storm water legislation, said the county is going to have to seriously consider the issue.

"I'm realistic about it. If we don't address the problem of a long-term funding source, we're only kidding ourselves," he said.

In the meantime, the county is trying to persuade 160 homeowners associations with storm water ponds that they're responsible for the work now, but the message isn't welcome.

At Congressional Country Club Estates off Persimmon Tree Road, homeowners have learned their association owns two storm water ponds so clogged that they no longer drain properly.

Repairs could be more than $21,000 for the approximately 90 homeowners.

"Had we known about it, we could have maintained these ponds over the years," said Gerald Royston, association president. "This is coming at us out of the blue."

Rejuvenating a Waterway

According to Montgomery County engineer Dan Harper, "Stream restoration is as much art as it is engineering."

Reviving an urban stream first requires keeping water away, at least temporarily. Unless it's slowed, rainfall from rooftops and pavement can overwhelm a stream's natural dynamics.

Constructed ponds and wetlands slow gushes of water. Dirt and pollutants settle as the water sits and cools, then gradually drains through pipes leading out of the constructed ponds. In developed areas where space is at a premium, underground pipes and concrete chambers hold and slowly release water.

Within the stream channel, engineers use techniques that imitate natural forces shaping a forest stream. They arrange rocks and logs to re-create sequences where shallow water moves swiftly over rocks, settles into pockets of deeper pools and meanders through calm stretches. All three settings combine water, light, oxygen and vegetation in ways that attract and sustain creatures.

Eroded banks are regraded, replanted and embedded with protruding wads of tree roots that shelter young fish. Tight bank curves may be fitted with large stones stacked to provide shaded nooks for fish. In the adjoining floodplain, shallow pits are dug to collect rainwater and attract frogs and salamanders.

"We look at what nature does [in a stream] and what nature is lacking because of man's activities," Harper said.