Mauricio Carreon was not alarmed when the river in Leon began rising May 24. The river usually swells in the spring.
But the waters rose for five days, says Mr. Carreon, a member of the city civil defense team. The river gushed into houses that still bear bullet holes from the nation's civil war. It twisted bridges, destroyed 200 homes, washed away roads. Damage in Leon was about $15 million.
Casualties were kept to a minimum -- 87 injured, 45 dead -- because the city's local defense teams were on full alert . . . although for an expected United States invasion, not a flood. The defense teams simply shifted from military protection to flood protection and are credited with saving many lives.
Yet Nicaragua is having a hard time recovering after the flood -- its worst natural disaster since the earthquake of 1972, which leveled Managua, the nation's capital.
International relief has been far less than expected -- a blow to a government that is bankrupt after the civil war.
The first offer of flood relief -- $60,000 -- came from Britain, which is keen to mend relations in Latin America after the Falklands crisis.
Then came a promise of 7,000 tons of cereals from Argentina -- a virulent foe of Nicaragua until the Falklands war, when Nicaragua supported the Argentines. United States flood relief was limited to 3,500 tons of food and a grant of $25, 000, delivered through the local Red Cross because the US suspended aid to the Nicaraguan government in 1981.
Ambassadors in Managua raised another $1,000. The Soviet Union contributed a mobile field hospital.
Jaime Balcazar, the UN Development Program representative who coordinates international relief aid, puts total relief funds raised so far at $4 million --
In contrast, diplomats here reckon that $1.2 billion was received by the Somoza government in 1972 after the earthquake. Much of that, they say, went into the coffers of the Somoza family.
But if the Sandinista government is dismayed or angered by this year's low level of international aid, it doesn't show it.
''We are like a column of ants,'' said Dr. Sergio Ramirez, a member of the three-man junta that runs the Nicaraguan government. ''We disperse, but then we regroup to continue our march.''
The remark is more than stock revolutionary optimism. Foreign diplomats here say the May floods helped to consolidate national unity, and to blunt a perceived US effort to isolate the Sandinistas in Central America.
The Sandinistas are acutely sensitive to natural disasters. They are well aware that the earthquake of 1972 helped fuel their own revolution.
In l970, when Lake Managua overflowed, many of the poor moved out and set up in squatter towns like Ciudad Sandino, named after the Sandinista hero.
When the '72 earthquake struck, the revolution had a natural and highly politicized following among the thousands of displaced persons -- particularly after Somoza embezzled the relief funds.
One of the first acts of the government after the May floods was to promise land to those who were displaced. Youth groups were quickly mobilized to provide round-the-clock food and medical care.
In terms of lives lost, this year's floods were relatively mild -- nothing like the 10,000 people who are thought to have died in the earthquake. Nor was the damage so awesomely concentrated.
But the economic havoc wrought by the floods was, if anything, more serious. One-third of country's crops are damaged. Expected costs for housing some 60,000 homeless people is $25 million.
Since early June Mr. Carreon and other local officials have been guiding teams from the United Nations and foreign embassies to the more spectacular sites in an increasingly urgent effort to raise funds.
''There must be no more Ciudad Sandinos,'' said one young government relief worker.