AUGUSTA — The Mainewatch Institute, treating broad areas of economic, environmental and social concerns, said Monday that Maine “stands at a crossroads” — with prospects for future prosperity and progress threatened by shortsightedness.

In a wide-ranging report issued from its Hallowell headquarters, the 3-year-old think tank asserted there is “a sense of unease” among many Mainers who worry that the state “is gradually losing its unique qualities and the ability to shape its own future.”

Such fears may be partially justified, the report said: “Inaction is not an option.”

“But there are also bright spots,” the report said, citing stepped-up efforts in growth management and environmental preservation and urging policy approaches that look beyond short-term economic gains.

To achieve what the report termed a “sustainable future,” Maine must confront pollution, low-quality development and the excessive harvesting of natural resources, the institute said. In addition, the state would benefit from investments in education and training that could be expected to result in reductions in crime and poverty.

Moreover, Maine’s ability to promote economic security while preserving the environment and fostering social gains depends on the development of affordable housing and good jobs — which in turn depends on both capital spending and long-range planning, the institute authors said.

The report also listed numerous “indicators” designed to serve as benchmarks and serve as measures of progress in specific areas.

For instance, toxic air pollutants were classified as a “major problem,” subject to limited regulation, while levels of industrial emissions were said to be “improving locally,” due to stricter legal enforcement.

Road conditions were described as a “growing problem,” with 21 percent — up 3 percent in 1988 from 1986 — said to be poor. But energy conservation was termed “improving,” with energy efficiency estimated to have increased by 20 percent to 30 percent during the past 15 years.

The institute credited Maine with making “enormous progress” in cleaning up its rivers, but noted that about 1,500 miles of combined sewers with more than 350 outfalls discharge raw sewage into waterways during heavy rains.

Despite a decade of healthy economic conditions, more than 61,000 households around the state still fall below the poverty line, the report said, adding that more than 1,600 homeless people used state-supported shelters during the 1989 winter.

“There has been talk of the `two Maines’ — one rural, one urban. But there are other factors at work creating another `second Maine’ defined not geographically but economically and socially,” the report said, adding: “no systematic strategy has been prepared to deal with the problem of poverty.”

“What’s different about this report,” said Mainewatch President John Fitch, “is that, by presenting a broad range of issues next to one another in one place, we hope to stimulate a new understanding of the interdependence of Maine’s environmental, economic and social systems.”