While the risk of flooding is increasing, the school's inundation measures are not progressing, and the National Council of Experts is considering not only preparing for the largest disaster once in 1000, but also measures for disasters on a relatively easy scale. We have compiled an interim report that it is important to do.
The Ministry of Education, Culture, Sports, Science and Technology's Council of Experts revealed for the first time last year that while there are nearly 7,500 public schools in the inundation area, only 15% are taking measures against inundation in the facility. In response to this, we compiled an interim report last month for the promotion of countermeasures.
Among them, if we focus only on the largest heavy rain once in 1000, which is the assumption of the hazard map, it will be technically difficult to take measures or it will cost a huge amount of money, which will be a factor that the measures will not proceed. In addition, it is important to consider measures that are relatively easy to tackle by utilizing the assumption of inundation that occurs as often as once every 10 years.
For example,
▽ In heavy rain once every 10 years, install a waterstop to prevent flooding of the facility, ▽ In heavy rain once in 100 years, receive and transform electricity so that the school can be restarted early. For example, raising the equipment.
On the other hand, considering that the actual situation differs depending on the region, when considering countermeasures, it is included that the Board of Education collaborates with the river management staff of the national and local governments to organize information such as the depth of inundation assumption and the probability of occurrence. increase.
The Ministry of Education, Culture, Sports, Science and Technology plans to promote the utilization of the national system to subsidize the cost of inundation countermeasures, and to compile a final report that includes a guide for specific countermeasures by the end of this fiscal year.
Preventing damage once every 200 years, even if it is difficult once in 1000
Although it is difficult to prepare for the largest flood disaster once in 1000, some local governments are working on possible measures.
Omori Daiyon Elementary School in Ota Ward, Tokyo, spent nearly 15 million yen on the ward's budget when rebuilding the school building from three years ago to last year, and installed a large waterstop with a height of about 90 cm. I installed it in a place.
It cannot be prevented if there is an inundation of about 2 meters, which is expected to occur once in 1000 years, but it can be expected to prevent damage until heavy rain once in 200 years.
By doing so, if we can protect the school lunch room from flooding, we will be able to resume school lunches early even after the disaster, and we believe that the impact on homes and children will be minimized.
In Ota Ward, 65 schools, which is more than 70% of all elementary and junior high schools, are in the inundation area. We have made a major review of the measures against inundation in elementary and junior high schools.
Currently, we are working on measures that can be taken by the entire ward, such as relocating a disaster prevention warehouse that stores generators and disposable diapers to the second floor of the school building.
Yusuke Tanaka, chief of the Ota Ward Educational Facilities Division, said, "There is a real problem that the more measures you take, the more expensive it is, so I think it is difficult to prevent all the heavy rains once in 1000 with hard measures. However, it is safe to have a major disaster such as Typhoon No. 19, so it is necessary to have a sense of crisis and think about countermeasures that suit the school and the community. "
Some schools have minimized damage with possible measures
As a result of taking hardware measures to the extent possible, some schools have minimized damage.
Shioda Junior High School in Ureshino City, Saga Prefecture, was damaged by a heavy rain once every 50 years, flooding a nearby river and flooding the school by about 1 meter. , Incorporated a stilt structure.
It was installed by the city with a budget of about 280 million yen, using a national grant, and the height from the ground to the first floor is 2.6 meters, and there are classrooms and staff rooms on it. Is placed.
In addition, in order to give students time to evacuate, the height of the school yard and courtyard is made lower than the surrounding area to have a water storage function in order to delay the inundation of the school building.
As a result of these measures, in August of last year when it rained nearly 440 mm in one day, the underfloor of the school building was submerged by about 70 cm, but there was no damage to the classrooms and the school was closed as usual after the summer vacation. It means that I was able to resume.
Principal Masaaki Ikeda said, "I was grateful that the stilt structure is functioning very well because I was able to get through the floor in the heavy rain last year. I think it can withstand a certain amount of heavy rain."
On the other hand, according to Ureshino City, although there are other schools in the inundation area, it is difficult to take similar measures because it costs a lot of money to build a high-floor structure.
The city wants to consider necessary measures based on the interim report of the national expert meeting.
Expert "Efforts from cost-effective measures"
Nozomi Kiuchi, a doctor at the National Research and Development Corporation Building Research Institute, who is a member of the Council of Experts of the Ministry of Education, Culture, Sports, Science and Technology, said, "If we try to take measures focusing only on the flood damage once in 1000, which is the basis of the hazard map. , I will stop thinking due to technical and cost issues, and I will not be able to take any measures. First, realistic measures that can be taken against inundation once every 100 or 50 years are realistic. It is necessary to take measures within a reasonable budget. "
On top of that, Mr. Kiuchi said, "The school facility is not only a place for children to learn, but also a shelter for the local residents. First, we will work on cost-effective measures to reduce damage to the school building. It can be expected to have great effects, such as speeding up recovery. "