Mai Mai Spring (Hadano City, Kanagawa Prefecture) Complete Guide | Natural Spring Water from “Showa’s 100 Select Waters” Spouting from 20 Meters Underground
“Mai Mai Spring” located in Imaizumi, Hadano City, Kanagawa Prefecture, is one of the Hadano Basin spring water group selected as the Ministry of the Environment’s “Showa’s 100 Select Waters.” This spring water spot, developed on the grounds of the South Community Center, is enjoyed as a public water source where anyone can freely use groundwater that naturally springs forth from 20 meters underground without using electric pumps.
This article provides a detailed explanation of the characteristics of Mai Mai Spring, the origin of its name, water quality information, access methods, and surrounding tourist information about this precious natural blessing.
Mai Mai Spring | Artesian Well Representative of Hadano Basin Spring Water Group
Abundant Groundwater Resources in Hadano Basin
Hadano City forms a basin terrain surrounded by the Tanzawa Mountains to the north and west, the Shibusawa Hills (part of the Ōiso Hills) to the south, and Mt. Kobo to the east. Due to this unique topography, the Hadano Basin contains abundant groundwater said to exceed even Lake Ashi, and was selected as the Ministry of the Environment’s “Showa’s 100 Select Waters” in Showa 60 (1985) as the “Hadano Basin Spring Water Group.”
Mai Mai Spring is one of the representative spring water spots comprising this Hadano Basin spring water group, and has become a symbol of Hadano’s rich water environment.
Development History of Mai Mai Spring
Mai Mai Spring was originally a monitoring well for groundwater quality installed on the grounds of Hadano City’s South Community Center. In Hadano City, groundwater contamination progressed during the period of high economic growth, so the city implemented groundwater quality remediation projects.
As these remediation projects progressed, the water quality of the monitoring well improved significantly and reached drinking water quality standards. Consequently, in Heisei 12 (2000), “Mai Mai Spring” was developed as a public water source where citizens could experience Hadano’s restored clear spring water.
Self-Spouting Mechanism | Natural Spring Water Without Power
The most distinctive feature of Mai Mai Spring is the phenomenon of water naturally “spouting” from 20 meters underground. This well reaches a confined groundwater layer (confined aquifer), so groundwater is pushed up to the surface by natural pressure, and water continuously springs forth without the use of electric pumps.
The clear water spouting steadily and continuously conveys the power and blessings of nature to those who visit.
Origin of the Name “Mai Mai Spring”
What is a Maimaizu Well?
The unique name “Mai Mai Spring” derives from an ancient special well called a “maimaizu well.” A maimaizu well is a well with a structure where the ground is dug down in a mortar-like shape, with a well at the bottom.
The shape of descending to the well along a spiral pathway from the surface resembles the spiral pattern of a snail shell (called “maimai” in dialect), which is how it came to be called a “maimaizu well.” This well form was created during the ancient period (from the Kofun to Nara periods) and developed as an ingenious method to obtain water in areas with deep groundwater levels.
Historical Value and Continuation to Modern Times
The maimaizu well is a precious cultural heritage that tells the story of Japan’s water usage history. Hadano City’s adoption of this historically significant well’s name reflects respect for the region’s water culture and a desire to convey to modern times the gratitude toward water that has continued since ancient times.
While the actual Mai Mai Spring utilizes a modern monitoring well, through its name one can feel the long history of Hadano’s people and their relationship with water.
Water Quality Information of Mai Mai Spring
Clear Groundwater Suitable for Drinking
The water at Mai Mai Spring meets drinking water quality standards as a result of the groundwater quality remediation project. However, since it is not treated with chlorine disinfection like tap water, a notice stating “Since this water is not disinfected like tap water, please use it at your own responsibility” is posted at the facility.
When drinking, it is recommended to boil the water before use.
Medium-Soft Water with Good Mineral Balance
The water quality at Mai Mai Spring is medium-soft water with a hardness of approximately 94 mg/L. Considering that the average hardness of Japanese tap water is approximately 50–60 mg/L, this is somewhat harder but still within the soft water range.
This water contains minerals such as calcium and magnesium in good balance, characterized by a mellow and easy-to-drink taste. Even when used in cooking, tea, and coffee, it is excellent water quality that brings out the flavor of ingredients.
Continuous Monitoring of Groundwater Quality
Mai Mai Spring was originally installed as a monitoring well for groundwater quality, and regular water quality inspections are still conducted by Hadano City. Through this continuous monitoring, stable water quality is maintained, and an environment where citizens and tourists can use it with confidence is preserved.
Facility Information of Mai Mai Spring
Easy-to-Use Facilities
Mai Mai Spring is installed in a corner of the parking lot on the grounds of Hadano City’s South Community Center. The facility is outdoors and can be used freely 24 hours a day.
Three water taps are installed, allowing multiple people to use them simultaneously. By bringing containers such as plastic bottles or water containers, you can carry home water for personal use.
Parking Available with Good Access
The South Community Center has a complete parking lot, making it convenient for water collection by car. It is also close to the Tomei Expressway “Hadano Nakai Interchange,” and many people from the Yokohama area and beyond visit to collect water.
Since it is installed quietly in a corner of the parking lot, it may be slightly difficult to find on a first visit, but it can be reached without problems by using the community center’s directional signs or map applications.
Access Methods to Mai Mai Spring
Access by Train and Bus
From Odakyu Odawara Line “Hadano Station”
- Walking: Approximately 15 minutes
- Bus: Get off at “Minami Community Center” bus stop on Kanagawa Chuo Kotsu Bus line, then immediately arrive
From the south exit of Hadano Station, head straight southward, cross Prefectural Route 62 (Hiratsuka-Hadano Line), and proceed toward the Imaizumi area. This is a flat, easy-to-walk route with residential areas and shops along the way.
Access by Car
From Tomei Expressway
- Approximately 10 minutes from Hadano Nakai Interchange
- Via National Route 246 toward Hadano city center
From Odawara-Atsugi Road
- Approximately 15 minutes from Hadano Interchange
Car Navigation Settings
- Facility name: Hadano City South Community Center
- Address: 598 Imaizumi, Hadano City, Kanagawa Prefecture
You can use the South Community Center’s parking lot, but priority is given to community center users, so try to keep your time brief when collecting water.
Tourist Spots Around Mai Mai Spring
Other Spring Water Spots in Hadano Basin Spring Water Group
When you visit Mai Mai Spring, we recommend touring other spring water spots that make up the Hadano Basin spring water group.
Kobo’s Clear Water
- Approximately 10 minutes walk from Hadano Station
- Historic spring water associated with Kobo Daishi
Imaizumi Spring Water Pool
- Within walking distance from Mai Mai Spring
- Developed waterside park
Gomateyashiki Water
- Northern Hadano city area
- Domestic water loved by local residents
The “Famous Water Tour” visiting these springs is a popular sightseeing course where you can experience Hadano’s nature and history.
Enjoying the Nature of Tanzawa
Hadano City is known as the gateway to the Tanzawa Mountains and is also popular as a base for climbing and hiking.
Omote-Tanzawa Prefectural Citizens’ Forest
- Rich natural forest and streams
- Hiking courses suitable for beginners
Mt. Kobo Park
- Famous as a cherry blossom viewing spot
- Panoramic viewpoint overlooking Hadano city center
Shin-Seiryoku Lake
- Mysterious lake born from the Great Kanto Earthquake
- Walking paths enjoying nature in all seasons
Hadano Historical and Cultural Facilities
Hadano City Sakuradote Ancient Tomb Exhibition Hall
- Preserves and exhibits archaeological remains from the Kofun period
- Learn Hadano’s ancient history
Hadano Tobacco Festival
- Hadano’s largest festival held every September
- Conveys the history of former leaf tobacco cultivation
Hadano City Tourism Association
- Convenient for gathering tourist information
- Local Hadano specialty products also available for purchase
Precautions When Visiting Mai Mai Spring
Etiquette for Water Collection
- Spirit of consideration: When multiple users are present, respect the order and avoid monopolizing the water for extended periods.
- Keep it clean: After use, do not leave the surrounding area wet, and maintain cleanliness for the next user.
- Take trash with you: Be sure to take away any trash such as container packaging, and maintain the aesthetic appearance of the facility surroundings.
- Consideration for community center users: The parking lot is shared with South Community Center users. When the community center holds events, congestion is possible, so consideration is necessary.
Handling of Water
- Boil before drinking: Since it is not chlorine-disinfected, boiling is recommended if drinking.
- Storage method: Place collected water in a clean container, store in a cool dark place, and use as soon as possible.
- Use at your own responsibility: There are notices at the facility, but use is at your own responsibility.
Suitable Times to Visit
Mai Mai Spring is available year-round, but each season has its characteristics.
Spring (March–May)
- Mild weather ideal for water collection
- Beautiful cherry blossoms and new leaves in the surroundings
Summer (June–August)
- Cool spring water is refreshing
- Low water temperature, perfect for hydration in summer
Autumn (September–November)
- Comfortable weather
- Can be enjoyed together with Tanzawa autumn colors
Winter (December–February)
- Fewer users allow leisurely water collection
- Cold weather preparations needed
Mai Mai Spring as a Symbol of Hadano’s Environmental Conservation Efforts
Success of Groundwater Quality Remediation Project
The existence of Mai Mai Spring is a symbolic representation of Hadano City’s long-term groundwater quality remediation project. The clear spring water is the crystallization of efforts by citizens, businesses, and administration working together to remediate groundwater that was polluted during the period of high economic growth.
Sustainable Water Resource Management
Hadano City practices sustainable water resource management by restricting excessive pumping of groundwater and promoting appropriate replenishment (groundwater recharge). Mai Mai Spring serves as an excellent example of successful environmental conservation efforts, attracting attention nationwide.
Enhancement of Public Environmental Awareness
Public water sources like Mai Mai Spring provide opportunities for citizens to daily touch the blessings of nature and play a role in raising environmental awareness. As many citizens visit to collect water, it becomes a place where they can truly understand the importance of water and protecting the region’s natural environment.
Summary of Mai Mai Spring’s Charm
Mai Mai Spring is not merely a spring water spot but a special place where Hadano’s history, culture, nature, and environmental conservation efforts converge.
The clear groundwater naturally spouting from 20 meters underground symbolizes the rich water resources of Hadano Basin. The name derived from the ancient “maimaizu well” expresses respect for the region’s history and water culture. And the story of how contaminated groundwater was remediated through citizens’ efforts and restored as clear famous water teaches us the importance of environmental conservation.
When visiting Hadano, be sure to stop by Mai Mai Spring and experience this precious natural blessing. The cold, clear spring water heals the hearts and bodies of those who visit and awakens feelings of gratitude toward nature.
With its convenient access of a 15-minute walk from Hadano Station, parking availability, and 24-hour accessibility, Mai Mai Spring has become a beloved spring water spot not only for local residents but also for tourists from distant areas.
Before and after enjoying the nature of Tanzawa through hiking and climbing, during sightseeing that tours Hadano’s history and culture, or as an everyday water collection spot, Mai Mai Spring continues to provide nature’s blessings in various forms.
Mai Mai Spring, representing the Hadano Basin spring water group selected as one of Showa’s 100 Select Waters, will continue to be cherished as a precious natural resource of Hadano and a source of civic pride.
