Eleven years after the new town of Columbia was opened, developer James Rouse came into Washington to proclaim at a press conference yesterday: "We believe it really demonstrates there is a better alternative to suburban sprawl."

Rouse is board chairman and chief executive officer of the Rouse Co., which developed Columbia with Connecticut General Insurance Corp. He recently announced plans to step down the posts next year.

He said Columbia now has 45,000 residents and 20,000 jobs. The community is "racially open and, what is more important, it is racially friendly," he added.

The developer and mortage banker predicted that Columbia will become an area of 110,000 persons with 60,000 jobs in eight small towns around a centre city. He indicated that the development of Columbia will be nearly completed in 1988.

Rouse also said: "Had Columbia not happened, the people, the business and industry, and the institutions which make it a city would have been irrationally scattered throughout the Washington-Baltimore corridor in the standard pattern of suburban sprawl and commercial clutter along the hightways."

The developer admitted that Columbia "has tolerated some boxes" to make lower cost housing available and generally to provide a wide choice of housing. He estimated that Columbia has more than 1,000 units of subsidized housing.