![\"An](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2026\/06\/4518be0b0256905938501b4e0493d5de.jpg\")
<\/p>\nHello, everyone.<\/p>\n
This is Enta.<\/p>\n
The rainy season has begun, and it\u2019s that time of year when news reports of heavy rain are coming in from all over the country.<\/p>\n
Around this time of year, there are always reports from somewhere about \u201cembankments collapsing\u201d or \u201cslopes shifting.\u201d<\/p>\n
What\u2019s still fresh in our memories is the mudslide that occurred in Atami City, Shizuoka Prefecture, in July of Reiwa 3, isn\u2019t it? It\u2019s said that that event had a major impact on society.<\/p>\n
But that's beside the point.<\/p>\n
In this article, we\u2019ll discuss the \u201cEmbankment Regulation Act,\u201d which is said to have been enacted in response to the disaster in Atami.<\/p>\n
Since this is a legal matter, it\u2019s easy to think, \u201cWe\u2019re just contractors, so it doesn\u2019t apply to us,\u201d but no, this is actually a crucial issue\u2014especially for those of us who work on slopes and embankments.<\/p>\n
This time, rather than discussing how to memorize the provisions word for word, I\u2019ll give a rough overview of \u201cwhat will change on the ground\u201d from a practical perspective.<\/p>\n
However, since I\u2019m not a legal expert, please keep in mind that this is based solely on what I\u2019ve learned through my own research.<\/p>\n
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Apparently, the official name of the Landfill Regulation Act is the \u201cAct on the Regulation of Residential Land Development and Specified Landfills, etc.\u201d<\/p>\n
Since it's so long, everyone just calls it the \"Embankment Regulation Act.\"<\/p>\n
According to documents from the Ministry of Land, Infrastructure, Transport and Tourism, this law was enacted following the debris flow disaster in Atami City in July of Reiwa 3, as a fundamental revision of the previous \u201cAct on the Regulation of Residential Land Development, etc. (formerly the Residential Land Development Act),\u201d and came into effect on May 26, Reiwa 5.<\/p>\n
As far as I can tell from my research, the biggest change is that \u201cregulations are now applied uniformly nationwide, regardless of land use.\u201d<\/p>\n
It seems that the old land development laws basically applied to the creation of \u201cresidential land.\u201d<\/p>\n
But this new law regulating landfilling applies regardless of whether the land is residential, forested, or farmland.<\/p>\n
Furthermore, the article stated that regulations now extend beyond land development to include even \u201csimple soil disposal\u201d and \u201ctemporary stockpiling of soil and rock.\u201d<\/p>\n
Basically, it seems that \u201cdangerous ways of piling things up or disposing of them are off-limits no matter where you do them.\u201d<\/p>\n
![\"Fill](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2026\/06\/e153f7cd871b4a32fcedf6b2e66c44a0.jpg\")
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This is the part that people are most curious about\u2014\"So, at what scale does it become a problem?\"<\/p>\n
If you look at the guidelines published by various local governments, such as Yokohama City and Sagamihara City, you\u2019ll see that within \u201cRegulated Areas for Residential Land Development and Similar Construction,\u201d<\/p>\n
It appears that, generally speaking, if a project falls under any of the following categories, permission from the governor or mayor is required before work can begin.<\/p>\n
To be honest, I think this is the kind of line that gets caught up pretty quickly on-site, even with just a little grading or moving dirt.<\/p>\n
A 1-meter-high embankment? If you've ever worked on slope stabilization, isn't that just... Seriously?? It just feels like, \"Who cares?\"...<\/p>\n
By the way, here\u2019s a tip that\u2019ll come in handy.<\/p>\n
According to guidelines issued by Yokohama City and others,<\/p>\n
In cases where construction work such as residential land development is carried out in accordance with the terms of a development permit issued under Article 29 of the Urban Planning Act, a permit under the Landfill Control Act may not be required.<\/p>\n
In other words, it seems the point is that \u201cfor construction projects where safety has already been ensured through a development permit, there\u2019s no need to obtain a second permit.\u201d<\/p>\n
In other words, it seems that cases such as doing a little digging outside the scope of a development permit or building a retaining wall on your own are actually more likely to run afoul of the Earthwork Regulation Act.<\/p>\n
This is just based on my experience in the field, but I feel that the more I think, \u201cIt\u2019s a small job, so it should be fine,\u201d the more likely it is that I\u2019ll later realize, \u201cOh, this actually required a permit.\u201d<\/p>\n
It might be safer to narrow down your options at the very beginning.<\/p>\n
Even for subcontractors like us who specialize in specific types of construction work, the project comes to a halt if the general contractor fails to obtain the necessary permits. So it\u2019s not just someone else\u2019s problem, haha.<\/p>\n
*The figures above were provided as general guidelines for areas subject to regulations on land development and related construction work.<\/span> The reason slope stabilization contractors should be concerned about this law is that, for projects subject to permitting, there is a possibility that they will be required to \u201cuse proper, permanent structures to stabilize the soil.\u201d<\/p>\n According to the guidelines issued by Meguro Ward and other local governments, it appears that for construction projects involving earthwork that exceeds the permitted scale and is halted midway, a permit under the Earthwork Regulation Act is required, and the installation of concrete retaining walls or similar structures may be necessary.<\/p>\n And the point where it stated, \u201cIt is not possible to hold back the soil using temporary structures such as retaining walls.\u201d<\/p>\n In other words, it seems that the approach of \u201cjust putting up a temporary solution for now and figuring it out later\u201d doesn\u2019t really work anymore.<\/p>\n I'm like, \"Whaaaaaaat?!\" Seriously??<\/p>\n From our perspective as slope engineers, it seems this means there will be strict requirements for \u201cwork that permanently protects slopes,\u201d such as retaining wall construction, mortar spraying, vegetation restoration, and drainage work....<\/p>\n Furthermore, it appears that there is also a type of regulated area known as a \u201cSpecified Embankment, etc. Regulated Area.\u201d According to documents from the Ministry of Land, Infrastructure, Transport and Tourism, this designation applies to areas such as slopes that, even if located away from urban areas, could cause damage to residential properties due to topographical conditions.<\/p>\n In short, it seems that even a slope in the mountains could be a candidate.<\/p>\n It\u2019s getting harder to say that this has nothing to do with us, since we\u2019re always out in the mountains\u2026<\/p>\n It appears that the technical standards themselves (such as slope gradients, drainage facilities, bench cuts, and compaction standards) are specified in detail in Cabinet Orders, Ministry Ordinances, and the technical standards of individual local governments.<\/p>\n I think it's good that my workload is increasing in various areas, but it does feel like I'm taking on too much...<\/p>\n When legal issues come into play, the construction process itself becomes more problematic.<\/p>\n Here are some points to pay special attention to on-site:<\/p>\n First of all, it seems that you need to obtain permission \u201cbefore starting work.\u201d<\/p>\n This might seem obvious, but when things come up suddenly, there\u2019s a chance you might just \u201cget it done first,\u201d right?<\/p>\n Proceeding without permission is definitely the worst-case scenario.<\/p>\n If you suddenly find yourself with excess soil, should you get a permit first, or just spread it out flat so it\u2019s less than 1 meter thick?! lol<\/p>\n Next, I was told that there would be inspections, such as interim inspections during construction and a final inspection upon completion.<\/p>\n Therefore, keeping detailed records of the construction work\u2014including compaction control, the status of drainage installation, and the finished condition\u2014should help prevent problems later on.<\/p>\n And penalties.<\/p>\n According to explanations provided by local governments and the Ministry of Land, Infrastructure, Transport and Tourism, malicious violations\u2014such as unauthorized construction\u2014are punishable by imprisonment or heavy fines, and<\/p>\n It seems the system is designed to impose particularly heavy fines on corporations.<\/p>\n <\/p>\n Another thing that\u2019s easy to overlook is what happens after the construction is finished.<\/p>\n It is said that owners, managers, and occupants of land within regulated areas are obligated to maintain that land in a safe condition at all times.<\/p>\n I've heard that if a structure is deemed unsafe, authorities may issue a recommendation or order to install or modify a retaining wall.<\/p>\n In other words, we need to adopt the mindset of \u201cbuilding structures that will be properly maintained afterward,\u201d rather than just \u201cbuilding them and calling it a day.\u201d<\/p>\n Up to this point, I\u2019ve been writing things that might sound like threats\u2014like \u201cregulations have gotten stricter\u201d and \u201cthere are more things to watch out for\u201d\u2014but to be honest...<\/p>\n I think that, for those of us who work to protect slopes, this isn't all bad news.<\/p>\n Construction projects that don\u2019t rely on temporary fixes but instead incorporate proper retaining walls, slope protection, and drainage systems will become the \u201cnorm.\u201d<\/p>\n We need structures that aren't just built and then forgotten, but that can be maintained.<\/p>\n Unlicensed operations and substandard work\u2014the \"cheap but shoddy\" kind\u2014will be weeded out through penalties and inspections.<\/p>\n Ultimately, this leads to a situation where \u201ccontractors who do quality work get more jobs and are properly recognized.\u201d<\/p>\n As natural disasters become more frequent, the importance of the work involved in protecting slopes continues to grow.<\/p>\n It is said that this law was enacted in response to the disaster in Atami, but it is a system designed to prevent such incidents from ever happening again.<\/p>\n If that\u2019s the case, wouldn\u2019t it be us\u2014the people on the front lines who know the field\u2014who can do the job most effectively within that system?<\/p>\n Do you view regulations as \u201ccumbersome restrictions\u201d or as \u201can opportunity to put our skills to good use\u201d?<\/p>\n I'm thinking I'd like to go with the latter, lol.<\/p>\n <\/p>\n But I end up piling up a huge mound of sprayed sand... lol<\/p>\n <\/p>\n See you later.<\/p>\n
\nSince the specific implementation details may vary depending on the type of zone and the local government, please be sure to check the latest guidelines issued by the relevant local government when applying this in practice.<\/span>
\nI haven't personally cross-checked the original documents of every local government. These are simply representative standards that I found during my research.<\/span><\/p>\n![\"Flowchart](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2026\/06\/ab79231d2f14f9d9118d701fb72ecfb0.jpg\")
<\/p>\nFor slope engineers, this means \u201cyou can\u2019t get away with temporary solutions.\u201d<\/h3>\n
Common Pitfalls on Site (Permits Before Work Begins, Inspections, Record-Keeping, and Maintenance Obligations)<\/h3>\n
![\"On-Site](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2026\/06\/43efbaa597f1c9ea62a15680b35fb780.jpg\")
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