MoMoMo – Management of all water, for all, by all

Mooyoung Han and the university green roof

Mooyoung Han describes how a water management philosophy for Korea could revolutionise approaches to tackling the global water crisis.

As we seek to develop water practices fit for the future, we can look for lessons in the wisdom of the ancients. Much can be learned, for example, from the ancient Taoist philosopher Lao Tzu, who aligns positive motivation with the vital and precious resource of water with the statement, Supreme good is like water. This philosophy has much to offer in informing how we can adapt our relationship with people and the natural world.

This philosophy of water is of less use in how we respond to the climate crisis. We need a philosophy of water management. Sources here include Hongik-Ingan philosophy – benefiting human life widely, which is the founding spirit and educational philosophy of Korea, and can be interpreted to mean also the relationship between humans and nature, and the present and future generations. Another source is the four principles of water management combined in ‘Dong’, which is a letter representing a village. This covers: thinking first of water, a sense of community, leaving water in its original condition, and making full use of local rainwater.

These elements are combined in a new philosophy – one I am proposing to provide a focus on the management of all water, for all, by all. This is the MoMoMo water management approach – with ‘Mo’ being the pronunciation of the word ‘all’ in Korean. The basic principles of this are included in Korea’s Framework Act on Water Management in Korea.

The MoMoMo approach highlights best practice in water management and suggests methods that could be transferred across the globe. By providing practical and ethical standards, the MoMoMo approach can lead the way in shaping the equitable, sustainable, and community-focused management of water.

Examples of MoMoMo water management in practice

Star City rainwater management facility

Star City provides an excellent example of MoMoMo water management. This multi-purpose decentralised rainwater management facility in Gwangjin-gu, Seoul, is a global exemplar. A residential commercial complex built on an area of 5.4 hectares, it consists of a total of four buildings with 1300 apartments and a central garden. Due to the area’s high flood risk, rainwater management facilities have been installed. These consist of a 3000-ton capacity rainwater management system built in the basement of Building B, which is divided into three tanks, each with a capacity of 1000 tons. This collects around half of the 70,000 tons of rainwater that falls on the complex each year.

Following the community-focused philosophy of MoMoMo water management, the project benefits people downstream of the facility by preventing flooding and helps residents to reduce their water costs and live in a green environment fed by the collected rainwater. The system also benefits the wider environment by preventing the necessity to extract water from the River Han. By enabling water to be used locally the energy costs for the treatment and transportation of water are reduced, as are the associated greenhouse gas emissions. As a resource for all, the collected rainwater is available to all in the vicinity in the event of a fire or a disruption to the water supply. By adopting this water for all philosophy, conflicts over water are reduced and the resilience of the region to the impacts of climate change are enhanced.

As a result of this successful pilot project, an ordinance was enacted in 2004 in Seoul to provide economic incentives for the installation of rainwater facilities. This has now been adopted by more than 100 local governments nationwide.

Seoul National University Green Roof & Garden

A further example of the positive impact that MoMoMo water management can make is the building of the department of Civil and Environmental Engineering at Seoul National University. Building 35 has a roof of about 2000m2 of which an area of 840m2 has been transformed with the creation of flower and vegetable gardens, and ponds. Built in 2012, the facility has been operating continuously for 10 years, providing significant environmental and social benefits.Collected rainwater from the roof prevents downstream flooding and provides water for irrigation; water vapour is evaporated by the plants improving urban cooling; and soil provides insulation reducing winter heating costs. The vegetables and flowers produced in the roof gardens are distributed to schools and the local community, and annual activities –  such as potato harvesting and kimchi making – promote community sharing.

Mountain rainwater management, Slovakia

The methods utilised in mountain villages in Slovakia demonstrate how the philosophy associated with the MoMoMo approach can be applied outside of Korea. Mountainous areas in Slovakia have been subject to frequent floods due to climate change and forest damage caused by desiccation. In response, the government of the Slovak Republic approved a landscape revitalisation programme in 2011. Its aim was to build water retention measures with a total capacity of more than 250 million m3 to rejuvenate this damaged landscape, prevent local flooding, and boost biodiversity.

In a period of 18 months and using the labour of people from 488 communities in Slovakia, a large number of small rainwater harvesting facilities were built with a total capacity of 10 million m3 to slow down the outflow of rainwater from damaged slopes. Empowering local people, the project created jobs and reduced floods and droughts that had threatened the the region.

Monument of Cheugugi in the Peace Park of the Republic of Vanuatu

Rainwater for drinking at Ly Nhan Health Center, HàNam, Vietnam

One billion people worldwide do not have access to safe and affordable drinking water. Traditional centralised water supply systems are often costly and impractical in developing countries. A decentralised water supply system that utilises rainwater can provide a more suitable alternative.

The Rainwater Research Centre at Seoul National University successfully installed a rainwater drinking facility using a multiple barrier concept and nature-based solution in partnership with WHO at the Ly Nhan Health Centre, in Hà Nam, Vietnam, in August 2019. This facility was made with local materials and was constructed by residents. It is operated by local people at very low cost. Following the success of this pilot, WHO is considering expanding this approach to other communities.

Rainwater for drinking facility at Ly Nhan Health Centre in Vietnam (courtesy of WHO-Vietnam)

Evangelising peace in the island nations of the South Pacific

Island countries in the South Pacific are suffering from a lack of drinking water. In January 2019, the President of the Republic of Vanuatu visited the Rainwater Research Centre at Seoul National University and requested the installation of a facility to provide drinking water from collected rainwater. In August of that year, community-based rainwater for drinking facilities were completed in an elementary school, a public health centre, and the Peace Park.

On the day of the completion ceremony, the ancient Cheugugi rain gauge was unveiled as a symbol of peace, attended by leaders of 20 countries in the South Pacific. Amid concern that lack of water could cause conflict in the region, it seems that rainwater harvesting could contribute to peace. The monument recites the wisdom and the philosophy of Korean water management where rainwater has been valued and managed sustainably since 1441 AD.

Water management far from MoMoMo philosophy

So, let’s review the water management facilities and projects under way at home and abroad from the viewpoint of the MoMoMo water management philosophy. You can see that most water and land development projects – which do not consider the importance of rainwater and drain it instead of collecting it – aren’t MoMoMo.

Metropolitan wide-area water supply

To supply urban and industrial water in a period of rapid growth, Korea has built a series of dams and installed a wide-area water supply system that supplies tap water to cities and industrial complexes far away over mountains and valleys using pumps and pipelines. Thanks to this, our country has made progress. However, taking rainwater that has been falling and flowing in one basin for tens of thousands of years to another area is a selfish idea that does not consider the potential environmental impacts and the lives of the people and nature who are living in that basin. This method is not sustainable because it causes water disputes between regions and uses a lot of energy.

It makes more sense to collect all the rainwater that has fallen on the roofs of buildings in a city or industrial area, save water and use it efficiently, and then bring only the shortfall from outside. By doing this, flooding also can be mitigated without increasing the existing sewer system which is costly and time consuming.

Stormwater management for the single purpose of flood prevention

In the event of an extreme heavy rainfall, the Paldang Dam in the upper stream of the River Han discharges water from the river to control the water level. If this happens, the Jamsu Bridge in Seoul is submerged in water, causing problems for the citizens of Seoul. However, if water is not discharged, the land upstream will be flooded.

Existing dams on large rivers are having to cope with substantial changes to hydrological conditions due to climate change and increased runoff coefficients. If water in the dam is discharged, areas downstream will be damaged, if not discharged, the upstream will be damaged. From this concept, there is no win-win operation. Damage is either done to communities up or downstream.

During the flood season, the amount of water discharged is 10,000 m3 per second. This is equivalent to 860 million m3 of clean water resources which are discarded each day, which could ultimately lead to drought in spring. At the same time, large-scale stormwater reservoirs and stormwater pumping stations have been built for the sole purpose of flood prevention.

Instead of this ‘line wise’ approach of discarding rainwater to reduce the flooding of sewers or rivers, rainwater could be collected across the entire watershed to be used for a variety of purposes. This kind of ‘area wise’ water management has been traditionally practiced in Korea by making terraced rice fields or doombungs (small ponds, where rainwater is collected near the place it has fallen and put into the ground). This creates a multipurpose rainwater management facility that prevents flooding, secures water resources, assists groundwater recharge, and prevents heat waves and forest fires. These projects can be managed locally and create jobs for residents. Although the size of each facility is small, a large number of decentralised systems can have a great impact in improving climate change resilience.

Korean groundwater management

Korea’s groundwater management policy focuses on withdrawing groundwater without any efforts of returning it to the ground. As a result, the groundwater level gradually depletes, the surface dries up, destroying habitats. The land gets hotter and drier, leading to heat waves and creating conditions where forest fires can easily occur. This results in the necessity to dig deeper to access water, requiring larger and more powerful pumps to bring the water to the surface. These pumps use a lot of energy and power outages can lead to intermittent supply. This situation is not sustainable and is not considerate to the environment or future generations.

Groundwater levels can be gradually restored by allowing rainwater that has fallen evenly from the sky to infiltrate the ground in all areas. However, because the rate at which the groundwater level rises is very slow, the depleted groundwater level can be restored only if rainfall is allowed to infiltrate throughout the watershed, managed carefully over a long period of time.

High water consumption

According to data from the Ministry of Environment, the average daily water consumption of Koreans is 280 litres, which is more water than many other countries in the world. Because of this high consumption, water is transferred from place-to-place consuming vast amounts of energy.

Consumed water is converted to wastewater which then must be treated. There is also the problem of untreated wastewater being released to rivers during periods of heavy rainfall. Water conservation through public education programmes could help to reduce these problems.

Carbon dioxide production

More than 50% of water supply in Korea uses a wide-area water supply system, which supplies water across long distances using pumps resulting in high energy use. Fundamental analysis of all existing water management systems is required, and alternatives adopted to reduce carbon dioxide emissions.

Solutions that use a nature-based approach are in the spotlight worldwide. In the water management field, water conservation should be the priority of demand-side management. The potential of rainwater for multiple purposes of water conservation, flood control, the reduction of urban heatwaves and the prevention of forest fires should be re-evaluated. Such a policy would radically reduce the water sector’s carbon dioxide emissions and respond to the climate crisis.

A vision of the future

In response to the climate crisis at home and abroad, we should ask philosophical questions about how we can implement sustainable water management. Future water practices can learn from the wisdom of the ancients, and we can build on them with the MoMoMo philosophy.

Based on Korea’s experience and tradition of overcoming the harshest natural environment, the MoMoMo approach provides a valuable blueprint and a philosophy of water management. Although we can find some exemplary examples on MoMoMo being put into practice, there are still many examples around the globe of water management failing the people of today and tomorrow and disregarding the natural world. Harmony must be restored if we are to manage water respectfully.

In Korea we are fortunate that the philosophy of MoMoMo water management is reflected in the basic principles of the Framework Act on Water Management. If we make good use of this law and the water management systems that it supports, I believe that our ability to mitigate the climate crisis and solve water conflicts between regions can be transformed within a short time. In addition, I would like to present a vision that Korea can take the lead in water management by spreading this water management philosophy to the world. If people working in the water sector are socially present then we have a chance to manage the global water crisis and achieve, ‘All water, for all and by all’. •

Rain School initiative

BiTS students measuring rainfall at NBK School, Ha Long, Vietnam

People living in Monsoon regions have traditionally suffered from droughts and floods each year. For these people rainwater is either a blessing or a curse, depending on how it is managed. Some communities have cultivated site-specific wisdom to manage climate-related issues. This regional knowledge is shared and will be important to the young people who will become leaders in the future, helping them to maintain peace in the face of unprecedented extremes of climate. The Rain School provides a place where regional wisdom can be shared and creative approaches to water management can be discussed at community level.

The objective of this initiative is to raise awareness of rainwater management around the globe through the cultivation of international activities. By providing a platform for young students to share knowledge, it is hoped that the Rain School will help to build and maintain climate resilience and help support peace around the world.

At the school, a Rainwater for Drinking system produces drinking water that meets national drinking water quality standards. The quality and quantity of the collected rainwater is closely monitored by the students and water use is regulated to minimise water shortages during the dry season. Cameras enable remote monitoring and inform weekly reports.

To encourage innovation and collaboration a special group called BiTS (‘Bi’ means ‘rain’ in Korean, ‘T’ stands for ‘Teachers’ and ‘S’ for ‘Students’) has been created. This group takes part in art and cultural activities, technology exchange and systems monitoring, and social activities.

The Rain School network’s reach now includes Vietnam, Cambodia, Thailand, Laos and Myanmar and will soon expand to other regions, such as South Asia (SARNET) and Africa thanks to the financial support of the Mekong Institute and ROK MOFA.

The Rain School is registered on the United Nations’ Partnership Platform, a global registry of voluntary commitments and multi-stakeholder partnerships committed to supporting the Sustainable Development Goals.

More information

The author:

Mooyoung Han is Emeritus Professor at Seoul National University, Korea, the chair of IWA Rainwater Harvesting and Management Specialist Group, and chief executive officer of Rain for All.