Ojomachi Reisen (Cold Spring) Okayama Prefecture | The Full Picture of a Historic Spring Water Selected as One of Japan’s Top 100 Waters
The “Ojomachi Reisen” located in Ojomachi, Naka Ward, Okayama City, Okayama Prefecture, is a precious spring water with history and tradition that was selected as one of Japan’s Top 100 Waters by the Environmental Agency (now Ministry of the Environment) in 1985 (Showa 60). This cold spring, through which the subsurface water of the Asahi River flowing through Okayama City emerges, has been carefully preserved since the Edo period as the official water of the Ikeda clan, feudal lords of the Okayama Domain, and has been cherished by local residents as the finest water in Bizen Province.
Currently developed as a park called “Omachi Aqua Garden,” it has become a place of rest for citizens. This article comprehensively introduces information about this famous water, including its historical background, water quality characteristics, access methods, and precautions for use.
What is Ojomachi Reisen?
Ojomachi Reisen is a spring located in a residential area of Ojomachi, Naka Ward, Okayama City, with the subsurface water of the Asahi River as its water source. Subsurface water refers to underground water that has infiltrated from a river into the ground and flows through the sand and gravel layers of the riverbed and banks. Water that has infiltrated underground from the Asahi River emerges at the surface as clear spring water after passing through natural filtration, which is Ojomachi Reisen.
The name “cold spring” derives from the fact that the water temperature remains low throughout the year. Groundwater is not easily affected by external air temperature and feels cold in summer and relatively warm in winter. This stable water temperature and abundant water volume are among the reasons why it has been highly valued by people since ancient times.
What is the Top 100 Waters?
The Top 100 Waters is a list of 100 excellent water environments across the nation selected by the then Environmental Agency (now Ministry of the Environment) in March 1985 (Showa 60). This selection was carried out with the aim of raising public awareness of water quality conservation and promoting water environment conservation activities by local residents.
The selection criteria comprehensively evaluate water quality, water volume, water accessibility, and conservation activities. Within Okayama Prefecture, in addition to Ojomachi Reisen, “Shiogama Reisen” in Maniwa City and “Iwai” in Kagamino Town, Tomata County (※actually, the Top 100 Waters in Okayama Prefecture are “Ojomachi Reisen,” “Shiogama Reisen,” and “Iwai,” three locations) have been selected, and Ojomachi Reisen is a precious presence as the only Top 100 Water within Okayama City.
However, being selected as one of the Top 100 Waters does not necessarily guarantee that the water is suitable for drinking. When drinking, it is recommended to confirm with the local municipal government and perform appropriate treatment.
History of Ojomachi Reisen
Development in the Edo Period
The history of Ojomachi Reisen dates back to the third year of Jokyo (1686) in the Edo period. In this year, the cold spring was developed by Ikedatsunajiro, the feudal lord of Okayama Domain. Ikeda Tsunajiro is known as a respected ruler who greatly contributed to the development of Okayama Domain, and was a person who promoted numerous cultural projects such as the construction of Okayama Korakuen.
It is believed that spring water existed in this area before Ikeda Tsunajiro’s development, but once the water source was protected by the feudal lord’s order and water channels were developed, it became possible to use it more stably.
Official Water of the Ikeda Clan of Okayama Domain
After development, Ojomachi Reisen was positioned as the official water of the Ikeda clan of Okayama Domain. Official water refers to water used for the feudal lord and official purposes of the domain, and its use by ordinary commoners was restricted. The water from this cold spring was highly valued as drinking water for the feudal lord and as water for tea ceremony, earning high regard as “the finest water in Bizen Province.”
Throughout the Edo period, this cold spring was strictly managed, and various regulations for water quality conservation are believed to have been established. Such historical conservation activities are one reason why high-quality water has been maintained to the present day.
Changes After the Meiji Period
After the Meiji Restoration, when the clan system was abolished, Ojomachi Reisen ceased to function as official water and came to be used as living water by local residents. Until the early Showa period, people in the surrounding area regularly drew water from this cold spring and used it for drinking, cooking, washing, and other purposes.
However, as urbanization progressed, the surrounding environment changed dramatically, and as residential areas expanded, the importance of water source conservation came to be recognized. Following its selection as one of the Top 100 Waters in 1985, Okayama City undertook full-scale conservation and development projects.
Development of Omachi Aqua Garden
Overview of the Park
Following its selection as one of the Top 100 Waters, Okayama City opened “Omachi Aqua Garden” in 1997 (Heisei 9) to preserve Ojomachi Reisen and raise citizens’ interest in water. This park was designed not merely as a water-drawing point but as a comprehensive water-friendly space for interacting with water.
Within the park, water-drawing stations, rest areas, and information boards have been developed, creating an environment where citizens can easily visit and enjoy the famous water. Although the surrounding area is residential, the development as a park has also enabled it to serve as a community space for the region.
How the Water-Drawing Station Works
Currently, water cannot be drawn directly from the original spring outlet of Ojomachi Reisen. This is a measure to avoid direct contact from the perspectives of water source conservation and hygiene management. Instead, a water-drawing station is installed in Omachi Aqua Garden that supplies water by pumping it from the cold spring.
At the water-drawing station, water from the cold spring can be drawn by turning a faucet. Many citizens regularly visit and carry away water in plastic bottles or polyvinyl containers. The number of visitors increases, particularly in summer, seeking cold spring water.
The original spring outlet is located a few minutes’ walk from the park, and public access is restricted to protect the water source. The water that can be drawn at the park is conveyed from this source.
Facility Operating Hours and Equipment
Omachi Aqua Garden is basically open 24 hours and can be visited at any time. However, regarding use of the water-drawing station, it is recommended that water drawing be avoided during early morning and late night hours out of consideration for nearby residents.
Benches and pavilions and other rest facilities are also installed in the park, allowing visitors to spend time leisurely after drawing water. Additionally, information boards explaining the history of Ojomachi Reisen and the Top 100 Waters are installed, so that visitors can understand the value of the cold spring.
A dedicated parking lot is not provided, so use of public transportation is recommended. On-street parking should be avoided so as not to disturb neighbors.
Water Quality Characteristics and Analysis Results
Basic Characteristics of Water Quality
Ojomachi Reisen maintains clear water quality because the subsurface water of the Asahi River, which is its water source, is naturally filtered as it passes through underground sand and gravel layers. The water temperature is stable at approximately 15 to 17 degrees Celsius throughout the year, feeling cold in summer and relatively warm in winter.
As a characteristic of subsurface water, compared to surface water (water flowing on the river surface), it has the advantages of less turbidity and smaller temperature fluctuations. Additionally, as it passes underground, it comes to contain an appropriate amount of mineral content from the soil, resulting in a mellow taste.
Water Quality Analysis Results for Omachi Aqua Garden
Okayama City regularly analyzes and publishes the water quality of Omachi Aqua Garden. Testing is conducted on water quality standard items and water quality management target setting items, confirming the safety of the water as drinking water.
However, the official position of Okayama City is to “recommend boiling when using as drinking water.” This is a safety-focused response that takes into account the possibility of secondary contamination during the water conveyance process from the source to the water-drawing station or from contact with air at the faucet.
Water quality analysis is conducted monthly, with items such as coliform bacteria, general bacteria, pH value, turbidity, odor, and taste being checked. To date, no abnormalities exceeding standard values have been reported in tests, but due to the possibility of water quality fluctuations caused by changes in the natural environment and rainfall, continuous monitoring is carried out.
Efforts for Water Quality Conservation
The Water Quality and Soil Section of the Environmental Conservation Division of the Okayama City Environmental Bureau takes the lead in promoting water quality conservation activities for Ojomachi Reisen. Specifically, conservation of the environment around the water source, periodic water quality testing, and awareness-raising activities for citizens are being implemented.
Around the water source area, restrictions on the location of facilities that could become sources of contamination and preservation of green spaces that promote rainwater infiltration are being carried out. In cooperation with local residents and civic organizations, cleaning activities and environmental conservation activities are also regularly implemented.
In order to pass on the spring water selected as one of the Top 100 Waters to the next generation, a conservation system in which both the government and citizens cooperate is a major characteristic of Ojomachi Reisen.
Precautions for Use
Precautions When Drinking
As mentioned previously, Okayama City recommends boiling water from Ojomachi Reisen when drinking it. Being selected as one of the Top 100 Waters does not guarantee that it can be safely consumed as-is.
When boiling, continuing to heat for at least 1 minute after the water reaches a boil can reliably kill pathogenic microorganisms. Additionally, it is recommended to store the drawn water in a clean container, keep it in a cool, dark place, and use it as soon as possible.
Particularly when infants, elderly people, or those with compromised immune systems drink the water, it must be boiled before use. If choosing to drink raw water, the decision is made at your own discretion.
Etiquette for Drawing Water
Since many citizens use the public water-drawing station, it is important to observe the following etiquette.
- Avoid prolonged occupation and be considerate of those arriving later
- When drawing large quantities, avoid peak times
- Do not dirty the area around the water-drawing station; take trash with you
- Be mindful of noise and do not disturb nearby residents
- Do not bring pets close to the water-drawing station
- Do not place containers directly on the ground; exercise hygiene considerations
By observing this etiquette, an environment is maintained where everyone can comfortably use the famous water.
Possibility of Water Quality Changes
As a natural spring, water quality and water volume may fluctuate due to rainfall and changes in the surrounding environment. Particularly after heavy rain, turbidity may temporarily occur.
If you notice any abnormality in the color or odor of the water when visiting to draw water, it is recommended to refrain from drawing and contact the Okayama City Environmental Conservation Division. Additionally, it may be prudent to wait several days after typhoons or heavy rain for water quality to stabilize.
When abnormalities in water quality are confirmed, Okayama City quickly makes the information public and, if necessary, takes measures to restrict use.
Access Methods and Surrounding Information
Location
Address: Ojomachi, Naka Ward, Okayama City, Okayama Prefecture
Ojomachi Reisen (Omachi Aqua Garden) is located in the Ojomachi district of Naka Ward, Okayama City, in a residential area. It is in the eastern area east of the Asahi River, to the east of central Okayama City.
Access by Public Transportation
By Train and Bus:
- Approximately 20 minutes by Okayama Electric Railway bus from JR Sanyo Main Line “Okayama Station” to “Ojomachi” bus stop, then approximately 5 minutes on foot
- Take a bus route heading eastward from Okayama Station toward the Ojomachi area
When using public transportation, the number of buses may be limited, so it is recommended to check the timetable in advance.
Access by Car
It is approximately 15 minutes by car from central Okayama City, but as mentioned earlier, Omachi Aqua Garden does not have a dedicated parking lot. It is recommended to use nearby coin parking or public transportation.
Since the location is in a residential area, on-street parking disturbs nearby residents and should be absolutely avoided. When visiting to draw water, be mindful of parking etiquette.
Alternative Route to Ojomachi Reisen
When visiting on foot or by bicycle, using Jodo-ji Temple (a historic temple in Ojomachi, Naka Ward, Okayama City) as a landmark makes it easier to find the way. Omachi Aqua Garden is located a few minutes’ walk from Jodo-ji Temple.
It is also possible to access via a cycling path along the Asahi River. This is recommended as a route for visiting the famous water while enjoying nature within Okayama City.
Nearby Tourist Attractions
When visiting Ojomachi Reisen, combining it with nearby tourist attractions allows for a more fulfilling experience.
Jodo-ji Temple: A historic temple founded in the Kamakura period, with important cultural property buildings.
Central Okayama City: Major tourist destinations such as Okayama Castle and Okayama Korakuen are accessible by car in approximately 20 minutes.
Asahi River Riverbed: A natural area suitable for walks and cycling.
Other Top 100 Waters in Okayama Prefecture
There are three Top 100 Waters in Okayama Prefecture, including Ojomachi Reisen.
Shiogama Reisen (Maniwa City): A cold spring that emerges at the foot of the Hiruzen Plateau, with a year-round water temperature of approximately 10 degrees—extremely cold, with a refrigerator-like coolness even in summer.
Iwai (Kagamino Town, Tomata County): Spring water located in a mountainous area of the Chugoku Mountains, traditionally used as living water by local residents.
These three famous waters emerge under different topographical and geological conditions, each with distinctive characteristics in water quality and temperature. When visiting Okayama Prefecture, a “famous waters tour” visiting these locations is also recommended.
The Future of Ojomachi Reisen and Conservation Activities
Citizen-Participated Conservation Activities
Conservation of Ojomachi Reisen depends not only on government efforts but also on cooperation from local residents and civic organizations. Currently, regular cleaning activities and water quality monitoring activities are being carried out, centered on local neighborhood associations and environmental conservation organizations.
General citizens can also participate in these activities. Information on participation methods and activity schedules is provided on the Okayama City website and at the Environmental Conservation Division office.
Passing on to the Next Generation
Passing on Ojomachi Reisen, which has a history of over 300 years dating back to the Edo period, to the next generation is a responsibility of those of us living in modern times. To that end, conservation of the water source environment, appropriate use, and educational activities to convey the value of the famous water are important.
Okayama City is also implementing efforts to utilize Ojomachi Reisen as educational material as part of environmental education in elementary and middle schools. By having children learn about their region’s precious natural resources, the city is cultivating future conservation activity participants.
Balancing Urbanization and Water Source Conservation
Okayama City, with a population of approximately 720,000, is a core city expected to continue experiencing urbanization in the future. Balancing urbanization and water source conservation is not easy, but the case of Ojomachi Reisen demonstrates the possibility of protecting precious natural environments within a city over time.
Development restrictions around the water source, promotion of rainwater infiltration, and improvement in citizens’ environmental awareness are among the multifaceted approaches required to realize a sustainable society in which cities and nature coexist harmoniously.
Contact Information
Inquiries regarding Ojomachi Reisen and Omachi Aqua Garden are accepted at the following contact point.
Water Quality and Soil Section, Environmental Conservation Division, Environmental Bureau, Okayama City
- Address: Okayama City Hall North Building, 1-1-1 Oomo, Kita Ward, Okayama City, 700-8544
- Phone: 086-803-1282 (Main number)
- Hours: Weekdays 8:30 AM to 5:15 PM (Excluding Saturdays, Sundays, holidays, and year-end/New Year period)
You can freely inquire about water quality questions, interest in participating in conservation activities, and consultation regarding use of the water-drawing station.
Okayama City Official SNS
In addition to its official website, Okayama City provides information through various SNS. Latest information and event news regarding Ojomachi Reisen may also be posted, so following is convenient.
- Okayama City Official Website
- Okayama City Official Twitter
- Okayama City Official Facebook
Through these media, water quality test results and cautions regarding use are regularly disseminated.
Summary
“Ojomachi Reisen” in Ojomachi, Naka Ward, Okayama City, Okayama Prefecture, is a precious spring water with over 300 years of history dating to the Edo period and was selected as one of the Top 100 Waters by the Environmental Agency in 1985. With the subsurface water of the Asahi River as its source and serving as the official water of the Ikeda clan of Okayama Domain, it has a history of being called “the finest water in Bizen Province.”
Currently developed as “Omachi Aqua Garden,” it has become a place where citizens can easily draw the famous water, though boiling is recommended when drinking. Okayama City conducts periodic water quality testing, and the Environmental Conservation Division takes the lead in promoting water quality conservation activities.
In a time of advancing urbanization, preserving such precious natural resources is not easy, but Ojomachi Reisen has been protected to the present day through conservation activities carried out in cooperation between government and citizens. It is important that each of us begins by doing what we can to pass this famous water on to the next generation.
When visiting Okayama, be sure to stop by Ojomachi Reisen and experience the pure taste of this historic famous water and the blessings of nature that have been protected by local people.
