Local government authorities have not found any solution to prevent accidents similar to the one that took place a week ago when 18 campers on the Kurokura River were swept away in the town of Yamakita, Kanagawa Prefecture.

Tetsuro Ito, chief of Kanagawa Prefecture’s River and Port Division, said the prefecture has no guidelines for instructing campers who refuse to respond to flood or other warnings.

Since the accident, the prefecture has launched a discussion on camping, responding to calls that local authorities should introduce ways to regulate camping at rivers.

Mamitsu Okamoto, chairman of the Japan Autocampsite Federation, said camping at a riverside is considered most dangerous because there is always the possibility of a flash flood, and “authorities should come up with some kind of regulation.”

The issue, however, is not so simple. The River Law stipulates that “rivers are common national assets,” that are free for all residents to use.

Because rivers are public areas, the prefecture can only post signs warning that camping on riverbeds is dangerous on rainy days.

But many point to the responsibility of the campers who were involved in the accident.

Sources said those who were camping on the sandbar were told by local police to leave because of a possible flash flood.

A siren Friday evening, some added, also served as warning that the Kurokura Dam, 4 km upstream from the campers, was to release water. The dam is designed to generate power but not for water control. Its capacity to hold water is a mere 42,000 tons, and it is usually kept full.

“Its function is not to serve as a dam for water control, and it has no obligation to,” said Yutaka Takahashi, a visiting professor at Shibaura Institute of Technology in Tokyo.

A friend of the campers had also stopped by the site early Saturday morning to urge them to evacuate the area.

Tomomi Hakomori, 47, who was camping at the site, said “I was really scared in the pouring rain” upon hearing the siren Friday night.

Although Hakomori evacuated the area, only three other campers followed, he said.

Later that night, the rain slowed and the water level showed no visible change, misleading the campers who insisted on staying, the sources said.

At 6 a.m. Saturday, one of the campers in the group who had spent the night in a car came back to the campsite and urged them to pack up. The campers, however, evaluated the river and determined that things were fine since “nothing has changed.”

But half an hour later, the flood gate was opened at the dam to release water that was about to overflow.

Before the gate was opened, witnesses said local police and dam authorities argued bitterly over the releasing of water.

Police reportedly tried to keep dam operators from opening the gate, citing the campers who refused to leave. But dam officials argued that the facility was near full and holding any more water would break the dam.

According to the Kurokura Water Level Monitor Station, the water level downstream was about 50 cm at 6 a.m. Saturday, but rose quickly over the next two hours to about 100 cm. Less than four hours later, around 11:40 a.m., the river was 160 cm deep, and its raging current washed away the remaining 18 campers.

Hakomori, who helped save a 1-year-old boy swept away by the river described rescue efforts by police and firefighters, saying “everyone was doing their best. We all thought we could save them all until the last minute.”