Ogura-ike Pond (巨椋池)

Ogura-ike Pond used to exist in the southern part of Kyoto Prefecture, being encompassed by the present Fushimi Ward, Kyoto City, Uji City and Kumiyama-cho (although, considering its size, it would have been more appropriate to call it a lake).

Ogura-ike Pond was transformed through time by various civil engineering works including banking during the construction of Fushimi-jo Castle by Hideyoshi TOYOTOMI and, ultimately, it was converted to farmland by the land reclamation project that took place between 1933 and 1941. Prior to reclamation, the circumference and area of Ogura-ike Pond were approximately 16 km and 800 ha, respectively, being the largest freshwater lake in Kyoto Prefecture in those days.

History of Ogura-ike Pond
The history of Ogura-ike Pond can be broken down into several phases by the projects that significantly altered the shape of that pond.

Ancient times to the construction of Fushimi-jo Castle by Hideyoshi
The point where the Yodo-gawa River flows into Kyoto Basin is at the lowest altitude in that basin and the Uji-gawa River, the only river originating from Lake Biwa, formed an enormous drainage basin covering the area from the vicinity of Byodoin Temple, where that river runs into Kyoto Basin and upstreams of the points where the Uji-gawa River meets Kizu-gawa River (Kyoto Prefecture) in the western part of Kyoto Basin and the Katsura-gawa River (Yodo-gawa River system). This was Ogura-ike Pond of those days.

Ogura-ike Pond was located between Heian-Kyo and Heijo-Kyo, playing a major role as a stop over of waterway traffic from ancient times to the middle ages. Overland traffic went through the outer edge of the basin as if to avoid Ogura-ike Pond.

Many deltas were formed on the north side of Oguri-ike Pond. Geographical names such as Makishima-jo Castle and Mukaijima (Fushimi Ward) that remain today date back to the time when such places were once islands in the pond.

Construction of Fushimi-jo Castle by Hideyoshi to the Meiji period
Having accomplished the unification of the whole country, Hideyoshi TOYOTOMI built Fushimi-jo Castle where he located himself in his later years.

In conjunction with the construction of Fushimi-jo Castle, Hideyoshi built dikes along the Uji-gawa River (Ogura-ike Pond) to improve the river.
The following are three examples of Hideyoshi's Uji-gawa River improvement project:

Construction of Makishima-zutsumi Dike
The Uji-gawa River which used to directly flow into Ogura-ike Pond at the downstream from Uji-bashi Bridge was channeled towards the direction of Fushimi by installation of Makishima-zutsumi Dike. Consequently, the flow of water that used to directly run from the Uji-gawa River into Ogura-ike Pond was redirected to run into that pond at downstream from Fushimi only during floods. Makishima-zutsumi Dike was also referred to as Uji-zutsumi Dike.

Construction of Yodo-zutsumi Dike
Dikes were built from Fushimi towards the direction of Noso (the present Fushimi Ward, Kyoto City) along the right bank of the Uji-gawa River to fix the flow path of the Uji-gawa River. As a result, Yokooji-numa Pond (It was located in the expanse centered at the present Southern Kyoto Garbage and Sewage Plant in Yokooji, Fushimi Ward) was separated from the Uji-gawa River/Ogura-ike Pond. Top of embankment turned into the road connecting Fushimi and Yodo-jo Castle (in the Edo period) and, in the Edo period, became a part of the 53 Stations of the Tokaido Road and the 57 Stations of the Tokaido Road connecting Otsu and Osaka without going through Kyoto. The Yodo-zutsumi Dike was also referred to as the Bunroku-zutsumi Dike.

Construction of Ogura-zutsumi Dike and Bungo-bashi Bridge

Ogura-zutsumi Dike traveling down through Ogura-ike Pond as well as Bungo-bashi Bridge (the present Kangetsukyo Bridge) over the Uji-gawa River linking the Fushimi castle town and Mukaijima were built; consequently the distance between Fushimi and Nara was reduced through a route built on top of the embankment. Ogura-zutsumi Dike was also referred to as Ogura-zutsumi Dike or Taiko-zutsumi Dike.

In addition to the previous three dikes, Oike-zutsumi Dike and Nakaike-zutsumi Dike were built during this period and Ogura-ike Pond was divided into Oike Pond, Ninomaru-ike Pond, Ouchi-ike Pond and Nakauchi-ike Pond. It was, therefore, commonly referred to as Oike Pond during the Edo period and the name Ogura-ike Pond came into widespread use in recent years.

The Meiji period to reclamation
In 1868, the Kizu-gawa River dikes were washed out and, in cooperation with the Yodo clan, Kyoto Prefecture shifted the confluence where the Kizu-gawa River and the Uji-gawa River met downstream. This modification resulted in reduced backflow from the Kizu-gawa River to Ogura-ike Pond during floods.

However, since frequent flood damages continued to occur after that point in time, work was carried out to shift the Uji-gawa River as a part of the Yodo-gawa River Improvement project completing in 1910. After this, Ogura-ike Pond (Oike) was only left with a link to the Uji-gawa River in the channel between Yodo and Imoarai.

Consequently, it led to a situation where domestic sewage and agricultural runoff in the surrounding areas became backed up, contributing to various problems including reduced catches of fish due to the deteriorated water quality and outbreak of malaria. Additionally, the area has a large number of mosquitoes that emerge from spring through summer, making it impossible for residents to enjoy their evening meals without burning mosquito repellent to drive mosquitoes away.

Under these circumstances, residents lobbied and, as a project to increase the food production output, the first government-financed reclamation project came to be implemented.

During and after reclamation
The reclamation work was carried out with the government, prefecture and union sharing the burden of the project.

The government-run reclamation work was performed between 1933 and 1941 whereby Ogura-ike Pond was drained and was turned into farmland. Water from post drainage used to irrigate farm land was taken into consideration, with water drained using pumps and with landfills filled only to the degree that the bottom of the pond was filled with earth from Ogura-zutsumi Dike and islands dotting the pond.

Prior to reclamation, Ogura-ike Pond was 4 km in width (east to west), 3 km in length (north to south), 16 km in circumference (with the surface area being approximately 800 ha) and the average depth was 90 cm. It was a freshwater lake with the largest surface area in Kyoto Prefecture of those days.

As a result of reclamation, 634 ha of reclaimed farmland became available and, in conjunction with reclamation, a work to improve the existing 1,260 hectares of cultivated fields in the surrounding areas was carried out.

Subdivision of farmland in the drained land was based on Kintetsu Kyoto Line (then Nara Electric Railway) that is different from subdivision by Jorisei (system of land subdivision in ancient Japan) which remained in effect in the surrounding areas.

In 1953, a major flooding occurred washing out the embankments of the Uji-gawa River. With this, a large area of land including the entire area of Ogura-ike Pond prior to reclamation was flooded causing a disaster in which Ogura-ike Pond was restored in the reclaimed land. Taking this as an opportunity, Amagase Dam was constructed that was completed in 1964.

Summary of Ogura-ike Pond prior to reclamation
Natural environment
As a habitat to various plants and animals, Ogura-ike Pond has been providing a rich environment being beneficial to people.

With respect to birds, Ogura-ike Pond attracts many flocks of geese and has been used as a hunting ground.

The fishing industry has been blessed with fish making Ogura-ike Pond their habitat.

Reed growing along the shore was used as material for roofs and blinds at Kyoto Imperial Palace as well as cover for making tencha (powdered green tea) and Gyokuro (refined green tea) with tea (Uji tea) which was the local specialty of the surrounding areas.

There were native plants such as lotus, Chinese water chestnuts, Indian rice, and the picking and processing of such plants provided supplementary income for the area residents.

Additionally, lotus flower viewing has been very popular since ancient times whereby, virtually, one cannot mention Ogura-ike Pond without mentioning the lotus.

The carnivorous waterwheel plant (Aldrovanda vesiculosa) is native to Ogura-ike Pond which was designated as a natural monument for being 'Ogura-ike Pond, the locality of Aldrovanda vesiculosa' in 1921. With reclamation, however, this designation was canceled in 1940.

With respect to plants named after Ogura-ike Pond, there are Najas oguraensis Miki (with its scientific name indicating the native of Ogura-ike Pond), Nuphar oguraense Miki and Myriophyllum oguraense Miki.

Industries
Inland water fisheries in Ogura-ike Pond and farming such as paddy cultivation were practiced on the shore.

Other than the shore of the pond, three districts including Higashi-imoarai-mura (the present Kumiyama-cho), Danjo-cho (the present Fushimi Ward, Kyoto City) and Ogura-mura (the present Uji City) had exclusive fishing rights in Ogura-ike Pond. This fishing right continued until reclamation.

With respect to fisheries, various fishing methods including Eri (in kanji, 'enter' at right and 'fish' radical at left) fishing (a fishing method leading fish into a stationary net to trap and catch fish), shitakiryo and netfishing were practiced.

Since Ogura-ike Pond assumed flood control function in the vicinity, approximately several thousand hectares of lakefront was flooded over a long period during a flood. Consequently, farming in the area was subject to floods whereby one could expect normal crops only once every three years.

Large amounts of water is good for fishing but bad for rice production with water standing in paddy fields for a prolonged period of time; on the other hand, if there is a little water it is good for rice production but no good for fishing; as such, fishing and farming were at odds with each other.

Ogura-ike Pond in literature
Ogura-ike Pond has been favored by penmen and calligraphy/painting artists as a scenic area since ancient times.

In ancient times, there was a poem about Ogura-ike Pond saying, 'I hear loud sound over the cove of Okura (Ogura-ike Pond) and it seems that a flock of geese are flying to rice paddies in Fushimi,' Volume 9, No. 1699, Manyoshu (Collection of Ten Thousand Leaves).

A collection of notes entitled Oguraike-no-Hasu (Lotus in Ogura-ike Pond) written by Tetsuro WATSUJI, reminiscing the occasion when he was on board a lotus-viewing boat on Ogura-ike Pond in the summer of 1926 or 1927, described scenes of lotus-viewing at the time and was published in 1950. Taking root in this note on lotus-viewing, preservation of the lotus species in Ogura-ike Pond and the lotus-viewing event are continued by volunteers who have been growing lotus from lotus seeds of bygone days in their homes.

The present Ogura-ike Pond
Today, the reclaimed land continues to play a role as a major agricultural area within proximity of Kyoto and Osaka where various crops including rice and vegetables are being produced.

The reclaimed land and dry riverbed of the Uji-gawa River have become a landing zone for migratory birds.

Additionally, Gennai, the construction site of Uji-gawa River Dike on the north side of the reclaimed land, is home for one of the greatest reed vegetation in western Japan and is also valuable in terms of plant life. It is considered to be one of the largest roosting sites of swallows in Japan where several tens of thousands of swallows can be seen during the peak period in August through September.

In recent years, in addition to the conventional National Route 1 and the National Route 24, the Second Keihan Highway runs from north to south, whereas, Keiji By-Pass runs from east to west and, hence, it can be said that Ogura-ike Pond plays a key role in modern transportation.

The interchange of the Second Keihan Highway situated within the reclaimed land of Ogura-ike Pond is named the Oguraike Interchange.