When Judith Hart, then British minister for overseas development, told her friend Julius Nyerere that Britain wanted to undertake a major foreign aid project in his country's poorest region, the Tanzanian president sent her here to Mtwara.

It was a logical choice. Local industry here consists of two factories -- a bottling plant and a cashew-processing plant. Both are now closed indefinitely for lack of spare parts. Farmers here struggle to produce crops on sandy soil so thick with underbrush that plows are unusable. Roads are so bad that the government recently tore up the asphalt from one of the few paved roadways because it was too costly to maintain.

The British arrived here in 1978 with plans to make Mtwara a model of what is known in the international aid lexicon as "regional integrated development." Six years and $5 million later, only a few minor projects have been implemented, and Mtwara has joined the long list of ambitious aid programs that never got off the ground.

What happened here has been repeated in varying forms throughout Tanzania. Twelve different aid donors drew up plans for elaborate development projects in different regions during the late 1970s, but only three ever received substantial funding. The remainder, according to American political scientist Liz Kleemeier, who studied the projects, wound up as "wasted investments and planning documents which were never used."

Britain's program started out quickly enough when a team of seven economists and five crop, livestock and fishery specialists descended upon the region, which is about 300 miles south of Dar es Salaam, Tanzania's capital. They produced a multivolume planning book with 101 specific projects ranging from education to livestock medicine at a five-year cost of more than $23 million.

They also supplied what may be Britain's most enduring legacy here: 30 Land Rovers, 24 fully furnished houses and a six-bedroom guesthouse for expatriate workers, all constructed almost exclusively from British-made materials.

When project coordinator Selwyn Fraser-Smith arrived in 1981, the houses were about the only thing that had gotten under way. A crusty ex-colonial administrator with two decades of experience in East Africa, Fraser-Smith was determined to get the program going. "We started out and waited for the money to come and it didn't," he recalled. "I ended up banging my head against a brick wall."

The problem, as Fraser-Smith sees it, is that by the time the Mtwara project was ready to begin, British aid tastes had changed. Judith Hart and her Labor Party government were gone, replaced by Margaret Thatcher's Conservatives, who proved far les sympathetic to Nyerere's brand of socialist development.

The British began to focus on a project that had higher visibility and more glamor than working with peasants: the construction of a 210-mile highway in southwestern Tanzania. The project, which uses far more British-made equipment than Mtwara, also carried a much higher price tag -- 40 million British pounds at first, a figure that has grown to nearly 100 million.

As the road grew, Mtwara seemed to fade from view. In the end, only about a half-dozen projects have been funded, none of which seems particularly connected to others or to the original scheme. There is a modest fish-stocking program and a project to increase the yields of oilseed crops, such as peanuts and sesame and sunflower seeds. There is also a livestock project and a veterinary laboratory, even though Mtwara probably has the smallest number of livestock per capita in Tanzania.

One major project that could have been useful here -- teaching local farmers how to improve their farming techniques -- was never funded.

The British specialists who work on these projects say they have produced some interesting results, but most seem to doubt they will have any lasting impact. Agronomist John Simons says he has doubled yields of peanuts and sesame seeds but that none of his research has been applied to local villages.

"We send improved varieties of seeds up to Morogoro an agricultural research center in central Tanzania for multiplication, but little of it seems to come back here," he said.

Similarly, Lynden Wagstaff, a technician at the veterinary lab, says he expects his project will fold when he and the other British staffers there pull out in two years. "The same thing happened to me in Ghana," he said. "I went back to the lab three months after I left to get some samples, and the whole thing had been shut down."

Fraser-Smith says he has learned two lessons from Mtwara. First, a truly integrated development program is impossible because there are too many competing interests among government officials and aid bureaucrats. Second, "small is beautiful . . . . You have to start very modestly and build on experience, and that's just the opposite of what many of these aid programs have tried to do."

Back in Dar es Salaam, British aid officials concede that Mtwara has fallen considerably short of what was originally envisaged. But they deny that politics or the growth of the road project were responsible.

"The idea was fine in theory but didn't prove to be practicable," said J.W. Macdonald, the diplomat in charge of British aid here. "You don't pour in money if something isn't effective. It isn't the Thatcher government -- it's simply a realization that some things can't be done."