VASSALBORO — With dark rain clouds looming, sand was brought indoors Tuesday for Gov. Angus King’s ceremonial groundbreaking for a new state law enforcement academy at the site of a castlelike former private school.

The Oak Grove-Coburn School, a local landmark about eight miles north of Augusta, will be converted for Maine’s new Criminal Justice Academy. A new wing will be added to the building.

The current academy has outgrown the site it has occupied for 27 years, the former Thomas College campus in downtown Waterville. The new site is expected to open in 2001.

The state bought the former Oak Grove-Coburn school after it closed in 1989 for $11.5 million, but the academy’s move was set back for nearly a decade by high renovation costs and a shortage of money.

Plans call for the new academy to include a firing range, a K-9 training facility and an emergency vehicle operations course.

With the extra space, county and municipal police officers can be trained together with state troopers, said Department of Public Safety spokesman Stephen McCausland. The local and county police course will be expanded to 18 weeks, the same length as the trooper course.

With the consolidation of courses, state police will be able to fill vacancies more quickly than they can now, said McCausland.

The stately structure, which stands on a 113-acre site on a hill overlooking U.S. Route 201 and the Kennebec River, will house up to 175 students and staff after it is converted and the new wing added.

The existing academy occupies five buildings and encompasses 15 acres, nine of which are swamp and cannot be developed. The school has been showing signs of age, such as water stains on ceiling tiles in dorm rooms and broken floor tiles.

But officials said its main shortcoming was a lack of space to train new police officers, as well as game wardens, prison guards, dispatchers and part-time officers.

With rain threatening before Tuesday’s ceremony, sand was brought into an auditorium for the groundbreaking. Senate President Mark Lawrence, D-North Berwick, House Speaker Steven Rowe, D-Portland, state police Col. Malcolm Dow, and numerous other legislators and police officials also attended.

Bent Schlosser, chairman of the Vassalboro Board of Selectmen, said local residents are thrilled to see the state breathe new life into the Oak Grove school, which has long been part of the town’s identity.

“The state owned it for years and years and did nothing even to maintain it. So we were concerned it was going to collapse one of these days,” Schlosser said before the ceremony.

The two-story addition will not be visible from the highway and will not change the overall appearance of the building, Schlosser said.