A creek runs through Tom Murdoch's life, from early childhood memories of playing in Oil Creek near his grandmother's Pennsylvania home to his current project creating a 20-acre, $2.5 million "Stream Center" on Snohomish County's North Creek, which flows to Sammamish Slough and Lake Washington.

The headquarters of the Adopt-A-Stream Foundation he directs is at the south end of McCollum Park, just half a mile east of the 128th Street exit on Interstate 5. Thousands of people have been trained as streamkeepers since 1980, and the organization's stream manual is used in several states. The new center will provide tours similar to Bainbridge Island's Bloedel Reserve. Murdoch took us out to see North Creek:

Q: (Looking at muddy pond) This is the creek?

A: Beavers have built a 176-foot-long dam. They have a lodge and have taken down some of the trees we've planted. They're trying to dig a channel to our wetland ponds, and they dug air chambers that can break a leg.

Q: (Joking) Can we take a picture of you shooting the beavers?

A: We're going to install a beaver deceiver by putting some drains under the dam so it doesn't back up too much. Beavers can actually help creeks by creating wetlands and storing water. North Creek used to run full all year. Now runoff is so quick from impervious surfaces that we've had problems with seasonal flows since 1987.

Q: You built your own ponds, too?

A: This was a 4-acre parking lot in 1995, and it demonstrates the possibility of habitat restoration. We thought it would be good to walk the walk instead of just talking.

Q: How have you taught so many streamkeepers?

A: I like to surround myself with people smarter than I am. We've got 25 adjunct professors, all volunteers. You can get a Ph.D's worth of education by coming to our classes.

Q: A lot of people drive over North Creek without knowing it's there.

A: If you want to protect the mainstem, you have to protect all the branches. It's one little tributary at a time.

Q: Is that why your new Stream Center is in the middle of suburbia?

A: We want to give kids the kind of experiences they don't have in an urban environment. In a year or so they'll be able to walk boardwalks to the stream and wetlands, climb a tower into the tree canopy, and have a viewing window into a stream pond.

Q: What shape are our streams in?

A: We're treating patients which have pneumonia with aspirin.

Q: So are you an optimist or a pessimist?

A: I'm an optimist because all the problems I see in the creek can be solved. We just have to act pretty quickly.

Q: How can people get involved?

A: Go to our Web site at www.streamkeeper.org or call 425-316-8592. I like to quote Senegalese conservationist Baba Dioum: "In the end, we will conserve only what we love, we will love only what we understand, and we will understand only what we are taught."