The collapse of homebuilding in once-booming Scott County is having at least one quiet payoff:
A lot less pollution.
It's one leading theory, anyway, to explain why the Credit River, one of the county's most important bodies of water, may soon be taken off the state's list of impaired waters.
And it would be a particular point of pride in Savage, which boasts of its environmental-mindedness while acknowledging it does contribute to pollution.
"We've done some significant projects the last couple of years, and are doing more this year, to improve the runoff and reduce the flow of sediment to the Credit River," said Sam Lucido, water quality specialist for the city. "It's not exactly glamorous work, but it's paying off."
The Scott County board voted Tuesday to apply to the Minnesota Pollution Control Agency to remove the river from the state's impaired waters list after hearing that new figures show the river is far exceeding the cleanliness threshold.
Ironically, in fact, the new cleanliness data emerged from a study originally intended to find out how to solve its pollution problems.
The problem with the Credit River has been "turbidity," or suspended solids, a river's equivalent of smoke hanging in the air and getting into peoples' lungs.
The data that were used to list it as impaired, however, were compiled during an era when Scott County was in the midst of its building boom, said Paul Nelson, the county's natural resources program manager.
During 1998 and 1999, Nelson plans to remind the state, Savage and Credit River Township combined for more than 1,000 new-construction building permits. Over the past two years, that number crashed to 151, he said.
Recent metering that collects data every 15 minutes, Nelson said -- far more accurate than in the past -- shows the river exceeds turbidity standards only about 1.2 percent of the time.
"The standard is 10 percent," he said. "So we're well under that."
Scientists can only speculate about why things are better now, he said, but fewer construction projects with their dirt piles and more sophisticated erosion control requirements have certainly helped.
"We were just learning erosion control back then," he said. "And we've done a few projects along the river since then to restore stream banks, including stabilizing some ravines that cut through bluffs."
The news comes not long after state officials disclosed that Eagle Creek in Savage is seeing a remarkable recovery when it comes to trout, a sign that it's much healthier than it used to be. Moreover, Nine Mile Creek, north of the Minnesota River, has been taken off the impaired waters list.
County Commissioner Joe Wagner's question about whether Sand Creek, in his district near Jordan, is also getting cleaned up, drew a crisp "no."
"Sand Creek is impaired for various parameters," or types of pollution, Nelson said. "On that one, we can't make this case."
Sand Creek runs through a more heavily farmed area, while the Credit River's borders have gradually been converted into large-lot estates, which can create permanent vegetation buffers that help keep a waterway clean.
David Peterson • 952-882-9023