From a small stream, big questions.

How can Baltimore County, affluent and progressive among Bay watershed jurisdictions, let one of its most special environments decline?

Why must its citizens fight so hard and constantly and long to protect what the laws say we should protect?

Should governments finally admit they don’t know how to grow without taking it out of nature’s hide?

Small streams are less than a quarter of 1 percent of Maryland’s land and water surface; yet streams invest any landscape with a personality disproportionate to their mere acreage. They are where the Bay begins, close to every resident, where so many are first enchanted by the greater Chesapeake aquatic.

Yet more than 40 percent of the 10,000 stream miles in Maryland are in “poor or very poor” condition according to the state’s Biological Stream Survey. Another third are judged “fair,” and a fifth are “good.”

Water quality problems wouldn’t be your expectation on an autumn tramp down little Dipping Pond Run, coursing prettily through big oaks and maples, tulip poplars and beeches as it feeds cool, clear water to the Jones Falls from its 3-square-mile watershed in the lush Greenspring Valley, just north of the Baltimore Beltway.

A 6-foot waterfall gushes into a natural stone swimming pool, making one long for August heat and an excuse to dip in the run.

I first came here more than 30 years ago with Richard Klein, who had seen his own growing-up stream trashed by the county’s White Marsh Mall. He remains to this day a dedicated stream advocate.

He was comparing a ruined, urban stream, Herring Run in Baltimore, with the high-quality Dipping Pond Run. I later wrote that the undeveloped lands of the latter let rains soak into the soil — preventing destructive flooding — then allow it to seep out to recharge the stream in dry weather. Heavily paved-over Herring Run in contrast, in wet and dry, alternates between “delirium and coma.”

The superb stability, the harmony between watershed and water on Dipping Pond Run, I said, “translated into trout.”

Decades later — a few weeks ago — I followed Howard H. “Howdy” Burns on a three-hour hike of Dipping Pond Run, which he has explored for most of his 64 years.

It’s still “some of the best water quality we have in the Jones Falls system,” said hiking companion, David Flores, a water quality manager at Blue Water Baltimore who is now the Baltimore Waterkeeper.

But it’s not nearly what it was when Burns was a kid, or when Klein and I sampled fish and aquatic insects there around 1980.

Burns pointed out thick sediment on the creek bottom and clogging the floodplain in areas or where the stream’s channel has become shallow and widened threefold, which means warmer, less trout-friendly water and lost habitat in deep pools.

The amount of “impervious surface” in the watershed — the sum total of roofs, roads, parking lots and driveways — that shifts a Dipping Pond Run toward Herring Run has grown from less than 2 percent of the watershed to more than 7 percent in the last several decades.

That doesn’t seem or look like a lot; yet research shows that exceeding even a minor percentage of imperviousness around a stream causes measurable degradation in the water.

At 7 percent imperviousness — only 126 of about 1,800 acres — native brook trout and mayflies, indicative of high quality waters, have vanished or sharply declined. The run was the last refuge for “brookies” in the Jones Falls system as recently as 1995.

A lawyer, Burns has filed numerous legal challenges to bad sediment control that let tons of silt come down the run from the now-defunct Chestnut Ridge Country Club. He’s also tried to stop the bulldozing of the forest by Westwicke, an enclave of luxury homes, as well as the polluting development from Maryvale Preparatory School.

Burns has won some lawsuits, lost others. He plans to file more, the next against a developer pushing for more lots on the old country club golf course.

His legal exchanges with developers and the county would fill books; but the bottom line seems to be that growth will be served, given the way we reckon progress; and water quality will come in second.

Just look at even more progressive and more affluent Montgomery County, which borders Washington, DC. A recent county ruling there will allow development to raise impervious surface along Ten Mile Creek, one of the last, best streams in Montgomery.

“A balance” between growth and environmental interests was their aim, county officials said.

And so it goes, never mind state slogans like “growing greener,” always balancing economic and environmental goals.

It’s a curious balancing — where the balance mostly shifts one way, toward more growth, less nature.