CHINA -- Students in this summer's youth conservation corps started their season by lugging enough rocks to riprap 400 feet of shoreline at the head of China Lake.

The goal of their work is to minimize the amount of dirt running into the lake as patrons of The Landing restaurant go back and forth from their boats and vacationers wade in and out of the water.

David Landry, head of the China Region Lakes Alliance that sponsors the conservation corps, said two sets of steps will be built for lake access.

In addition to China Lake, students will work on Webber, Three Mile and Three-Cornered ponds, all part of an interconnected chain of lakes with water quality problems.

Peter Wilkens of China is directing the corps this year. Wilkens graduated from Erskine Academy and is studying environmental science at Clark University.

Technical assistance is provided by Paul Mitnik, a retired Department of Environmental Protection employee who is Vassalboro's codes officer and plumbing inspector; and Jeff Freddenberg of the Kennebec County Soil and Water Conservation Commission.

Landry said the conservation corps started in 1996.

Youngsters, mostly high-school students, have riprapped shoreline, planted shrubs and trees to create buffer strips, ditched driveways and done other types of physical labor to limit runoff into lakes the alliance covers.

Landry said water running into the lakes carries particles of dirt. The dirt carries phosphorus, and phosphorus nourishes the algae that turn China Lake green late every summer.

Residents on or near any of the four lakes can get free advice about limiting erosion and runoff from the lakes alliance, and may be able to get conservation corps youngsters to work on their properties.

Anyone in need of help can reach corps director Wilkens through the China or Vassalboro town offices, or e-mail lakesal liance@yahoo.com.