WHEN WE HEAR A SUMMER THUNDERSTORM AT NIGHT, many of us roll over and go back to sleep. Solange Filoso, on the other hand, gets in her car and drives to a stream.

To study restored streams in Anne Arundel County, Filoso went driving by day and sometimes by night, in summer and in winter. Every two weeks, in daylight, she collected water samples from the streams for chemical analyses. She also measured the speed of stream flow during storms. "I remember being so wet once that I had to go to a store and buy new clothes and boots. I put them on and went back out there" to the stream to finish collecting data.

Long storms would send her out on night trips to check on her automated monitoring machines. Each held 24 bottles timed to collect samples as often as every 15 minutes. When longer storms would fill up the bottles, Filoso had to retrieve them and restock the machine with empties. That meant stashing all those full, one-liter bottles into a backpack — "It was heavy," she says — and then humping the whole load up some steep stream banks in the dark.

Now Filoso gets help with lugging her monitoring gear from her scientific colleagues. One of those helpers, Michael Williams of the University of Maryland Center for Environmental Science, is also her husband.

Intensive monitoring like this is not only hard work, it can also be time consuming and expensive: it costs up to $80 per bottle to have a commercial laboratory chemically analyze each water sample. "Doing good monitoring requires investment," Filoso says. In fact, the three years she spent monitoring Howard's Branch and five other streams in Anne Arundel County, with funding from the county government, was a relatively long span; often, money is available for no more than one year of monitoring after a restoration is completed, she says.

When she started her work in Maryland's streams, Filoso had been no stranger to flowing water. A native of Brazil, she has done research on the Amazon, the world's largest river, and she hopes to apply aspects of what she's learning about stream restoration in Maryland to a project in that country. She says some of the same issues carry over from Maryland to Brazil, where the clearing of forested areas has jeopardized the quality and quantity of water supplies to the Brazilian population.