Solution Overview & Team Lead Details

Our Organization

Gravity Water

What is the name of your solution?

Gravity Water

Provide a one-line summary of your solution.

Gravity Water turns rain into safe water for public infrastructure through innovative rainwater harvesting and filtration technology.

Film your elevator pitch.

What specific problem are you solving?

Managing freshwater resources is one of humanity's most essential steps in adapting to a changing climate. Based on the Intergovernmental Panel on Climate Change projections, anthropogenic climate change will continue to increase risks in physical water availability and water-related hazards throughout all regions, intensifying drought and precipitation events. In coastal areas, rainfall fluctuations, tropical cyclones intensification, and continued urban development will increase the risk of flooding, water pollution, saltwater intrusion, and water availability. These challenges require immediate action to improve the adaptive capacity of communities worldwide.

In urban areas, more land is becoming covered with pavement and other impervious surfaces, preventing rain from recharging local aquifers and leading to catastrophic flooding. At the same time, the growing population and industry are increasing the amount of water extracted from the ground, lowering water tables, and introducing the risk of saltwater intrusion. 

Water scarcity and pollution currently serve as a significant challenge for rural- and last-mile communities in ensuring basic health and resources needed to develop livelihoods dependent on agriculture. Moreover, as climate change intensifies, rural communities are facing an uphill battle in accessing a dependable and safe water source throughout the future.

What will happen if we continue increasing groundwater extraction while significantly reducing the amount of rain that can recharge our groundwater sources? How can we help vulnerable regions become more resilient to a changing climate? What steps can we take now to help communities address their challenges while also giving them the tools to increase water security and pollution throughout the future? The solution is found in one of the world's oldest technologies, rainwater harvesting.

What is your solution?

Gravity Water helps communities build water security and climate resilience through retrofitting public infrastructure with its innovative rainwater harvesting and filtration technology. Gravity Water's technology combines rainwater harvesting, elevated storage, and gravity-fed filtration, providing schools and other public infrastructure with thousands of liters of safe water daily. In addition, Gravity Water builds its systems using locally-available materials and skill sets, empowering communities to manage, maintain, and implement the solution independently; this human-centered approach ensures Gravity Water systems are more resilient to failure over time.

Last year, Gravity Water augmented its technology to allow schools and other public infrastructure to operate entirely off rainwater. Through an automated process, Gravity Water's technology enables schools to switch between their traditional water source and rainwater, ensuring maximum efficiency in rainwater use per building. Through this technological advancement, Gravity Water is now helping schools conserve hundreds of thousands of liters of ground and surface water every year, which in turn supports the community in mitigating the effects of climate change and more extended drought periods.

Who does your solution serve, and in what ways will the solution impact their lives?

Gravity Water works primarily in urban, peri-urban, and rural communities throughout Nepal and Vietnam and has piloted its technology in multiple countries and regions, including Indonesia, Puerto Rico, and Costa Rica. In response to Gravity Water's transition to building climate resilience, the organization is now contracting with other groups to help build water security, including an upcoming initiative for over 40 schools in Taiwan.

In 2016, Gravity Water first deployed its technology to help rural, last-mile communities in impoverished areas access a reliable source of safe drinking water. Since most rural areas, especially in the Global South, lack access to adequate water infrastructure, Gravity Water saw an immediate need to provide these communities with place-appropriate technology they could use to manage and treat their water sources independently. Most communities Gravity Water works with fall under this category due to the combined benefit of providing improved drinking water and building climate resilience for each school.

In response to Gravity Water's transition to building climate resilience, the organization is now focusing on expansion into urban areas, growing its impact in the Kathmandu metropolitan area in Nepal and the Ho Chi Minh region in southern Vietnam. Additionally, Gravity Water is contracting with other groups to help build water security in target regions, including a recently secured initiative to introduce its technology to over 40 schools in Taiwan. Through working in urban areas, Gravity Water is helping communities mitigate water loss due to groundwater extraction.

How are you and your team well-positioned to deliver this solution?

Gravity Water focuses on a 100% local leadership model, with all country initiatives being directed by local nationals that have experienced the challenges Gravity Water addresses first-hand. For example, Gravity Water's National Director of Vietnam, Jane Nguyen, grew up in a farming village and family. Jane and her family grow rice, controlling the water that enters their rice fields using a traditional canal system. Jane's family has recently diversified to primarily grow other vegetables since the water is becoming less predictable for rice. When Jane isn't helping her family farm, she's helping tens of thousands of children around Vietnam access safe water and helps keep fresh water in the ground to extend their growing seasons. 

In Nepal, Gravity Water's National Director, Samundra Giri, grew up in a mountain village called Sindhupalchowk. When he was young, his village lacked access to electricity and treated water. Every rainy season, water illness would spike in his village due to contamination of fecal bacteria, cholera, and other pathogens. Though many communities in the region now have access to electricity, they still lack access to safe water. Today, Samundra is working with local governments to provide over 100 schools throughout the Kavrepalanchowk District with Gravity Water's technology, providing students with safe water and community members training on effective rainwater harvesting techniques. 

Jane and Samundra work closely with Gravity Water's Executive Director, Danny Wright, who mainly serves as a support system in developing strategic planning for expanding their national initiatives and helping position each National Gravity Water Initiative for scale. In addition to strategic planning, Danny helps develop strategic partnerships and funding to scale each country's program and provides the tools and resources to ensure adequate monitoring, evaluation, learning, and reporting for each initiative.

This year, Mr. Wright has established critical partnerships to help grow the success of Gravity Water in Nepal, Vietnam, and beyond, including a formal partnership with one of the largest rainwater harvesting companies in Latin America, Isla Urbana, and a partnership with one of the largest technology companies in the world to scale its impact to over 130 schools in Vietnam over the next 12 months. Lastly, Mr. Wright has also partnered with faculty at Santa Clara University to launch the world's most extensive study on the social, economic, and environmental benefits of retrofitting public infrastructure with rainwater harvesting and filtration technology; this study will result in a white paper report to provide development groups and other stakeholders with the critical data they need to make informed decisions on investing in rainwater harvesting at scale.

Which dimension of the Challenge does your solution most closely address?

Help communities understand and incorporate climate risk in infrastructure design and planning, including through improved data collection and analysis, integration with existing systems, and aligning financial incentives such as insurance.

In what city, town, or region is your solution team headquartered?

Kathmandu, Nepal (South Asia); Hoa Binh, Vietnam (SE Asia); Santa Cruz, CA (U.S.)

In what country is your solution team headquartered?

  • Nepal
  • United States
  • Vietnam

What is your solution’s stage of development?

Scale: A sustainable enterprise working in several communities or countries that is focused on increased efficiency

How many people does your solution currently serve?

Today, Gravity Water's solution will serve an estimated 45,960 individuals. The organization has reached over 80,000 people in at-risk communities since the organization's launch. 

Why are you applying to Solve?

In 2017, Gravity Water was selected as a finalist for the MIT SOLVE Challenge for the Sustainable Cities and Communities category. Unfortunately, with only a handful of projects completed and still a lot to learn about how the organization would achieve scale, the submission wasn't selected as Solver.

Since then, Gravity Water has matured significantly and is at an exciting and pivotal moment in the organization's journey. Gravity Water recently secured funding to transition to scale in both Nepal and Vietnam and has secured partnerships with local governments, global corporations, and foundations to significantly grow its impact over the next 12 months. 

As mentioned above, Gravity Water has expanded its scope of impact from clean drinking water to building climate resilience and water security for urban and rural areas. By launching a highly focused data collection program, Gravity Water, in partnership with Santa Clara University, will be able to provide governments, development finance institutions, and other key stakeholders with the most comprehensive dataset on the economic, environmental, and social benefits of retrofitting public infrastructure with rainwater harvesting and filtration technology. Through this effort, Gravity Water aims to provide governments and development groups worldwide with the information required to make informed decisions on investing in rainwater harvesting as a tool for mitigating water-related challenges imposed by climate change.

The MIT SOLVE community was a huge inspiration for Gravity Water at an early stage of its journey. Over the last six years, Gravity Water has worked diligently to grow its impact to reach hundreds of communities and position itself to effect change on a global level. The organization is now at a stage where it can leverage a partnership with MIT SOLVE to catalyze and scale growth for the organization moving forward. This moment is the perfect opportunity for MIT SOLVE and Gravity Water to come full circle in catalyzing change by providing the organization with the critical guidance, partnerships, mentorship, and support it needs at this pivotal moment. MIT SOLVE can help catalyze Gravity Water's growth in the immediate future to attain scale and build a water-secure future for millions of at-risk community members worldwide.

In which of the following areas do you most need partners or support?

  • Human Capital (e.g. sourcing talent, board development)
  • Legal or Regulatory Matters
  • Public Relations (e.g. branding/marketing strategy, social and global media)

Who is the Team Lead for your solution?

Danny Wright

More About Your Solution

What makes your solution innovative?

Gravity Water’s solution is unique in a couple of ways. First, it addresses the bottlenecks associated with bringing rainwater harvesting, a well-studied and proven technology, to scale. Billions of dollars exist each year to enhance climate resilience and water security; what’s lacking is the data required to make objective decisions on whether or not rainwater harvesting is a wise investment. There is a lot of research on rainwater harvesting as a practice, yet very few examples of implementation at scale. By developing this data, Gravity Water will provide stakeholders with the critical information they need to know whether or not rainwater harvesting is a good investment based on their needs.

Second, Gravity Water approaches scale through a sustainable finance model, incorporating governments and private industry sectors as funding partners.  As CSR and ESG continue to be a foundational part of global markets, significant opportunity exists in leveraging funding from industrial partners to scale rainwater harvesting to offset their groundwater extraction in local watersheds.

Regarding Gravity Water's technology, the organization has developed an innovative approach to professional rainwater harvesting and filtration that allows schools and other large structures to operate entirely off of rain and filter water to drinking water standards without dependency on electricity. The technology is built using globally-available materials, making the solution scalable, easy to manage and maintain by local communities, and replicable in design for other organizations and groups that aim to increase rainwater harvesting and filtration as a practice.

What are your impact goals for the next year and the next five years, and how will you achieve them?


Environmental Impact: Amount of groundwater conserved through rainwater harvesting per year. 

  • 104M liters per year (~27.5M gallons per year)

Economic Impact: Potential savings on water costs by schools.

  • $950K USD

Social Impact: The number of communities and community members provided safe/resilient water access.

  • 100,800 beneficiaries, 275 communities

Gravity Water has recently secured funding from corporate and philanthropic partners to expand its impact to serve over 100,000 beneficiaries in Vietnam, Nepal, and Taiwan by May 2024. 


Environmental Impact: Amount of groundwater conserved through rainwater harvesting per year. 

  • 1B+ liters per year (264M+ gallons per year)

Economic Impact: Potential savings on water costs by schools.

  • $20M+ USD

Social Impact: The number of communities and community members provided safe/resilient water access.

  • 1M beneficiaries, 2,750 communities

Over the next five years, Gravity Water expects a 10x growth in impact. Gravity Water's current model for scale is separated into three phases based on how it measures growth geospatially. The first phase focuses on second-level administrative boundaries (Provinces, Districts) and is funded through philanthropic, corporate, and government partnerships. The second phase focuses on sub-regional or state-level boundaries and is funded through philanthropic, corporate, government, and development finance institutional (DFI) funding. The third phase focuses on national program expansion and is primarily funded through DFI groups and governments.

Gravity Water is collecting data at scale in Phase I in Nepal and Vietnam, which it will leverage to secure larger funding for Phase II and Phase III expansion in each country. Gravity Water plans on specifically focusing on Nepal and Vietnam to attain Phase II until expanding focused operations in other countries, as it believes demonstrating impact at a national scale will be the fastest way to attain multinational expansion globally. 

Which of the UN Sustainable Development Goals does your solution address?

  • 4. Quality Education
  • 6. Clean Water and Sanitation
  • 11. Sustainable Cities and Communities
  • 13. Climate Action

How are you measuring your progress toward your impact goals?

Before project implementation, Gravity Water conducts the Organization's Baseline Survey and Site Assessment at each school, collecting baseline data on key indicators, including student demographic data, water access, use, and infrastructure, attendance, water expenses, and current challenges regarding water access and quality. Gravity Water utilizes this baseline data to assess every school's immediate outcomes and long-term impact through monthly and annual reporting. 

Gravity Water is implementing monthly remote surveying using Esri's Survey123 software, collecting data on each school's water use, system performance and user experience, attendance, and water expenses. However, Gravity Water has recently partnered with SOPACT ( and will be transitioning to SOPACT's platform to increase transparency and participation in data review by key stakeholders.

What is your theory of change?

Gravity Water's Theory of Change is as follows:


Installing professional rainwater harvesting and filtration technology at schools in communities in need.


Providing communities with a low-cost, sustainable, resilient, and safe water source at school every day.


Social - Increase student attendance by reducing days missed due to illness.

Economic - Reducing water expenses for schools.

Environmental - Reducing dependency on groundwater and surface water sources for schools. 


Social - Increasing educational outcomes by keeping children in school.

Economic - Enhancing educational capacity for schools through reducing non-educational expenses.

Environmental - Increasing water security and climate resilience for schools and surrounding communities by keeping water in the ground.

Describe the core technology that powers your solution.

Gravity Water combines traditional rainwater harvesting technology with innovative filtration and water-movement mechanisms. Though many communities worldwide practice rainwater harvesting, most rainwater harvesting installations are rudimentary in design, lacking key components to ensure efficient and beneficial use. 

Gravity Water's technology overcomes this challenge by incorporating two treatment systems for the rainwater and an automated valve system that allows buildings to connect rainwater to their entire water grid and automatically switch to using the rainwater once the rainwater levels become sufficient for supply. Furthermore, since this process is automated, it doesn't require turning on and off the system, ensuring that rain is always harvested and used, regardless of the time of day or personnel available to manage the system.

Gravity Water currently uses remote surveying and kinetic water meters to analyze the productivity and efficiency of its technology. The organization aims to incorporate cloud-based smart meter technology into its future systems to increase efficiency in data reporting regarding the technology. 

Which of the following categories best describes your solution?

A new application of an existing technology

Please select the technologies currently used in your solution:

  • GIS and Geospatial Technology

In which countries do you currently operate?

  • Nepal
  • Vietnam

In which countries will you be operating within the next year?

  • China
  • Nepal
  • Vietnam
Your Team

What type of organization is your solution team?


How many people work on your solution team?

Full-Time Staff: 6; Contractors: 10

How long have you been working on your solution?

7 years

What is your approach to incorporating diversity, equity, and inclusivity into your work?

Gravity Water commits to a 100% Local Leadership model for its operations. In every country that Gravity Water operates in, the primary leadership team is native to the country. Gravity Water doesn't employ Western support for operational aspects of the organization. Additionally, Gravity Water has a strong focus on promoting women's leadership within the organization, with the majority of the organization's staff identifying as women. To ensure Gravity Water is an equitable employer, it focuses on targeting minority demographics that don't have the same access to job opportunities as majority groups.

Your Business Model & Funding

What is your business model?

In 2019, Gravity Water completed its "Proof-of-Concept" stage as an organization by reaching its 10,000 child-per-day milestone for safe drinking water access through its technology and approach.

Gravity Water is now in its "Positioning-to-Scale" stage, with a focus on transitioning the Organization from a strictly charity-based model to a strategic partnership model, focusing on collaboration with local entities, including local governing bodies and other non-governmental organizations.
Gravity Water's current funding is supported through philanthropic support of the Organization's mission, with diverse revenue inputs including community-based fundraising initiatives, foundation support, and corporate and business sponsorships and grants. 

Gravity Water's primary market includes second and third-level administrative government groups, including Departments and Ministries of Education. Gravity Water partners with these groups to implement regional coverage of their services at schools, focusing on an entire administrative boundary at a time. For example, this year, the Organization is partnering with three municipality-level governments within the Kavrepalanchowk District of Nepal and multiple district-level and province-level governments in Vietnam. Gravity Water is utilizing this approach to demonstrate impact at scale and collect critical data on impact metrics, such as potential water cost savings and student attendance at the decision-making level. 

As Gravity Water expands, it aims to transition to providing matching grant opportunities for governments in developing water security infrastructure through leveraging philanthropic and corporate funding and contracting with larger development finance institutions, such as ADB and USAID, to help increase water security and SDG attainment throughout public infrastructure enhancement in key regions. Lastly, Gravity Water aims to transition to a skill-transfer approach, providing local community-based organizations and NGOs with funding and technical assistance in implementing the Organization's innovative technology.

Do you primarily provide products or services directly to individuals, to other organizations, or to the government?

Government (B2G)

What is your plan for becoming financially sustainable?

As mentioned above, Gravity Water aims to fund its impact at scale by tapping into the billions of dollars in development funding currently earmarked to enhance climate resilience and through contracting with governments to assist them in achieving their development targets. Gravity Water has confidence it will be able to secure funding from these sources, as its technology is affordable, immediately deployable, and can help governments significantly reduce costs in water-related expenses on their public infrastructure. However, to achieve partnerships at this level, Gravity Water understands that it must demonstrate its impact at scale and have measurable data to illustrate why investing in rainwater harvesting will be an ideal strategy to build climate resilience for specific areas. The Organization aims to achieve this over the next 18 months in response to recently securing funding to bring its technology to 200 communities and its formal research with Santa Clara University, resulting in a white paper report for policymakers.

Though Gravity Water sees development funding and government contracts as the primary financial engines to bring its solution to scale, the Organization will continue to partner with corporate sponsors and philanthropic groups. This funding will allow Gravity Water to support local CBOs and NGOs through a skill transfer approach and provide seed capital to expand Gravity Water in new countries and regions.

Lastly, to assist in long-term financial sustainability and to expand Gravity Water's solution to benefit the private sector, the Organization has begun the process for private market entry, including registering as a for-profit entity in Vietnam and Nepal. Additionally, Gravity Water's technology is currently undergoing a patent process, allowing the Organization to protect the technology in a private market landscape while providing open-use permission for social and non-revenue generating purposes. Finally, through launching a for-profit leg of the Organization, Gravity Water aims to provide affordable rainwater harvesting infrastructure to businesses and households through a social enterprise model, with a portion of profits feeding back to the nonprofit entity.

Share some examples of how your plan to achieve financial sustainability has been successful so far.

In the last 12 months, Gravity Water has quadrupled its annual revenue streams by focusing on a climate resilience approach and incorporating data measurement and management. This funding has been granted to Gravity Water from various family foundations, granting groups, and some of the largest corporations in the world (Gravity Water is open to sharing more specifics regarding these funding groups under an NDA). In Vietnam, Gravity Water has pending contracts with corporate groups interested in offsetting the water use associated with their manufacturing, which Gravity Water can offer in an affordable, communicable, and quantitative way. Additionally, Gravity Water has secured partnerships with other INGOs, including a recent contract to expand its solution to over 40 schools in Taiwan. 

In June, Gravity Water's Executive Director will be presenting at the Asian Venture Philanthropy Network Conference in Malaysia as one of two featured speakers on the "Climate Resilience in the Asia Pacific" panel hosted by Chevron. Through this opportunity and upcoming highlights in Asia-based news outlets, such as Water and Wastewater Asia, Gravity Water is confident it will continue to widen its network of potential philanthropic funders focused on the Asia Pacific region.

In addition to grants for implementing new projects, Gravity Water has secured funding to retrofit all its previous model systems to connect rainwater to the entire school grid and install water flow meters to expand data collection. Through this transition and Gravity Water's upcoming expansion, the Organization will collect data on the amount of rainwater harvested, which directly informs water cost savings, on over 250 schools monthly.

Lastly, Gravity Water has already formalized partnerships with multiple government offices throughout Nepal and Vietnam, with the government assisting Gravity Water's expansion through non-monetary support. Gravity Water will continue to leverage these partnerships to build relationships, trust, and approval before pursuing large-scale development funding opportunities.

Solution Team

  • SG SG
    Mr Samundra Giri Gravity Water
  • Mrs Jane Nguyen National Director of Vietnam , Gravity Water
  • Danny Wright Executive Director, Founder, Gravity Water
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