Experience the Structural Beauty of Dams! Did You Know There Are “Edible” Dams in Japan?

The first type we will introduce is the curry that represents an earth dam, also known as an earth-fill dam. An earth dam is one constructed by piling up soil and is a type that is not commonly recognized as a dam by the general public. Its structure is simple, consisting of a trapezoidal mound of earth designed to hold water, and it is often referred to as a “tameike” (reservoir) in the local area.

The first earth dam in Japan is said to be the Sayama-ike Dam in Osaka Prefecture, which was established in 616 AD and is still in operation today. Initially built to secure irrigation water, it now plays a crucial role in flood prevention. While there are approximately 2,750 dams in Japan, it is estimated that about 45% of them are earth dams. Even though they may not be widely recognized, nearly one in two dams is an earth dam. This is how it’s represented through curry.

The rice is stacked in a trapezoidal shape to faithfully recreate the earth dam. The pickled vegetables (called fukujin-zuke) represent the spillway, which is used to release water when the dam is at full capacity.

The most common type of dam that comes to mind when one thinks of a dam is probably the concrete gravity dam. It is said that about 40% of the dams in Japan are of this structure. This type of dam is built with concrete arranged in a triangular shape, relying on its own weight to hold back the water. Gravity dams are typically constructed in areas with a relatively solid foundation.

Release facilities come in various forms, with some having release gates across the entire dam face, while others may not have gates at all. The Miyagase Dam in Kanagawa Prefecture regularly conducts tourism releases, which have become a popular event.

This is a representation of the gravity dam created with curry.

It accurately replicates the structure of a gravity dam, supporting the pressure of the curry with the weight of the dam. The rice is shaped like a triangle when viewed from the side. The use of fukujin-zuke (a type of pickled vegetable) represents the release, which is a key feature. The drawback is that, due to the use of a large amount of rice, the balance between the curry and the rice becomes slightly uneven.

An arch-shaped dam features an impressive design with a beautifully curved structure. Many famous dams that you may have seen in videos or photos, such as the Kurobe Dam, Kawaji Dam and Kawamata Dam, are arch dams. The graceful curves of the concrete are impressive, making it a standout among dams, and there are likely many fans of arch dams. In reality, there are only 52 of these dams in Japan, which is about 2% of the dams in the country.

This is a representation of the dam created with curry.

It features a structure that distributes the pressure of the curry across both sides of the rice and the bottom plate. Compared to the gravity dam curry, the “dam” is thinner and has an arch shape, resulting in a smaller amount of rice than in the gravity dam curry. In addition to its beautiful appearance, this curry is popular for its excellent balance between rice and curry.

Dams are often thought to be made of concrete, but many are constructed from materials other than concrete. One such type is the rock-fill dam. It is primarily made of rock and clay and features a clay layer that is difficult for water to pass through, placed in the center and covered by rock. The central clay layer is called the core, and rock-fill dams can be broadly classified into three types: center core rock-fill dams, which have the core located in the center of the dam; inclined core rock-fill dams, which have the core arranged diagonally; and surface cutoff rock-fill dams, which lack a core and use asphalt or concrete on the reservoir side to create a waterproof barrier.

This is a representation created as a “rice-fill curry” instead of a rock-fill.

The rice (core) that holds back the curry serves as the core, while the rice (rock) around it absorbs the pressure of the curry. When eating, you can imagine the position of the core and think about whether you are having center core rice-fill curry, inclined core rice-fill curry, or surface cutoff rice-fill curry, making the meal even more enjoyable.

The rice is shaped like a dam and has the function of “holding back” like a dam. While the presentation as curry is abandoned, it allows one to appreciate the aesthetic beauty of the dam. The versions served at Sansyu-ya fall into this category.

The rice is shaped like a dam but does not have the function of “holding back” like a dam. It is often garnished with side ingredients on the downstream side, allowing one to enjoy the aesthetic beauty of the curry. The Kurobe Dam Curry falls into this category.

This refers to the curry offered at restaurants adjacent to dams. While it does not take the shape of a dam and is completely ordinary curry, it is named after the dam in relation to the local area.

The difference between 1 and 2 may not be immediately obvious, but the key point lies in whether the structure of the dam is accurately replicated.

The Tsuruta Dam is a concrete gravity dam boasting the largest embankment in Kyushu, with a length of 450 meters and a height of 117.5 meters.

In 2018, following the completion of the dam redevelopment project, the Commerce, Industry and Tourism Section of the Satsuma PR Division took the initiative to create something to promote the dam, leading to the launch of the dam curry project. First, they made a rice mold to replicate the dam. Initially, a wooden frame was made, and from that, a plastic mold was created, but issues arose, such as the rice not coming out of the mold properly and the shape not being stable. After making improvements one by one, a stainless steel mold was developed. However, during the tasting phase, feedback included comments like “there’s too much rice to finish.” The mold size was adjusted again and redesigned, and improvements were made, such as splitting the mold to make it easier to remove the rice, resulting in the final version of the mold.
Currently, the Tsuruta Dam Curry, made with this mold, is available at four restaurants in the town. While the mold is consistent, each restaurant adds its own twist to the dish through variations in the sauce, presentation and ingredients. It can be a fun experience to compare the unique Tsuruta Dam Curries from each establishment.

The original dam curry, Kurobe Dam Curry, is now loved as a local specialty that can be enjoyed throughout the entire region.

In 2009, 15 restaurants in Omachi City, where the Kurobe Dam is located, began offering the modern version of Kurobe Dam Curry. To be called Kurobe Dam Curry, the following rules were established.

Next, we introduce the Fujiigawa Dam Curry from Shirosato Town, Ibaraki Prefecture. This dam curry was created as part of a collaborative project involving students from Ibaraki Prefectural Mito Sakuranomaki High School Johoku Campus, students from Tokiwa University, and the Shirosato Town Community Development Cooperation Team, aimed at promoting Shirosato Town, known as the “least known town in Japan” in the “least attractive prefecture.” The project’s funding was raised through crowdfunding by soliciting support from backers. The curry is currently served at the restaurant in the Shirosato Town Health Promotion Facility – Hororu-no-Yu (limited to 5 servings per day).

This colorful curry, topped with a variety of ingredients, is fun to look at, but each ingredient also carries a special meaning.

The ingredients used are, of course, mainly local specialties. The rice for the dam structure is Koshihikari from Shirosato Town, known as "Kokekko Rice." The pork floating in the reservoir is "Shirosato King Pork," a rare breed that has undergone selective breeding over 10 generations in 20 years. This pork is characterized by its fine texture, luster, and firm, springy meat, and it has been certified by Ibaraki Umaimon-dokoro (a promotional initiative highlighting local specialties in Ibaraki). The shiitake and maitake mushrooms, representing the moss-covered dam, are grown at the Nanakai Mushroom Center in Shirosato Town. These mushrooms are carefully cultivated indoors, completely pesticide-free.

And this curry also has a "water release" feature. Before eating, be sure to pull out the valve (sausage) stuck in the dam structure and enjoy the fun of releasing the "water." This heartwarming dam curry, with its delightful story, is a dish you definitely want to try when you visit the area.

The Ozuchi Dam is in Kōka City, Shiga Prefecture. It's a rock-fill dam constructed to reduce flood damage in the middle and upper reaches of the Yasu River and to secure water for river maintenance, among other purposes. Surrounding facilities include a dam park, an observation square and a multipurpose plaza. The prefectural road that includes the top of the dam (crest) is part of a scenic route that leads to the Suzuka Skyline, making it an enjoyable spot to visit for sightseeing as well.

The most notable feature of Ozuchi Dam is its semicircular spillway. Due to topographical constraints, a conventional spillway could not be installed, so two spillways with a diameter of about 30 meters each were constructed to regulate the water level. The spillway's height is at an elevation of 292 meters. When the water level exceeds 292 meters, water flows out from the spillway. Watching the water cascade vigorously from the semicircular spillway creates an illusion that it might pull you in.

The Ozuchi Dam Curry, which replicates this distinctive dam, is served at the Okawara Onsen Kamoshika Villa Restaurant Gensokyo.

The curry sauce, featuring local wild boar and shigureni (a type of simmered meat or seafood), is delicious, simmered in coconut milk with plenty of spices. A halved boiled egg and fried eggplant are used to represent the circular spillway.

Upstream from the Ozuchi Dam is the Yasugawa Dam, which is a concrete gravity dam. It is currently used for agricultural water supply.

At the Okawara Onsen Kamoshika Villa Restaurant Gensokyo, Yasugawa Dam Curry is also served.

This dam curry, generously served with fried deer meat and plenty of wakasagi, is also very hearty. You’d definitely want to try both!