Terra Firma Rainwater Collective

The Democratic Republic of Congo is one of the world’s most vulnerable countries to the effects of climate change, yet among the least prepared to cope with the effects. Projected climate change impacts of increased temperatures and increased precipitation variability are expected to result in more intense flooding and erosion (USAID, 2023). At the same time, the population of Africa is projected to double by 2050 (UN, 2022). At that time, the already densely populated capital city of Kinshasa, DRC could be the largest city in Africa. 

Kinshasa’s water sources are polluted and increasingly dangerous. In the capital city of Kinshasa, over 70% of the 17 million residents do not have access to the city’s water supply (Kapembo, 2022). Despite abundant water availability along the Congo River and from equatorial monsoon rainfall of around 5 feet (1.5 meters) per year, the infrastructure for a water supply does not exist for most residents. Approximately 12 million people pay for water collected from distant wells/boreholes, springs, and/or surface sources; a task that disproportionately affects girls and women. In addition, due to the prevalence of unimproved sanitation services, areas around Kinshasa have levels of fecal contamination that significantly exceed World Health Organization guidelines for drinking water (Kayembe et al., 2018). Kinshasa’s struggle with access to water and sanitation are evidenced by the frequent outbreaks of waterborne diseases, which accounted for more than 75% of the medical visits between 2016 and 2019 (Kapembo, 2022).  

Urban flooding poses an existential threat to groundwater supplies. In addition to a lack of clean drinking water, as Kinshasa grows it is faced with the problem of unplanned urbanization where the once vegetated surfaces are now hardened or covered with roofs and roads, resulting in flooding and immense erosion. The erosion of the sandy soils result in 25-foot to 75-foot deep (7.6-meter to 23-meter) ravines that dissect neighborhoods, swallowing homes, roads, and utilities (e.g. Imwangana, 2015). The only affordable ‘solution’ to slow the erosion is to dump domestic trash in the ravines. Due to this complex confluence of circumstances, the University of Kinshasa now estimates that the city has over 900 of these impromptu landfills. This means 900 waste dumps where surface and groundwater are contaminated; 900 locations where disease vectors like rats, roaches, and mosquitoes propagate in densely populated neighborhoods.   

Under-resourced governments like these lack the means to adequately provide safe water supplies and management of urban runoff as populations and city boundaries rapidly expand. A distributed solution is needed to allow residents to develop a seasonal water supply from monsoon rains, capturing water before it hits the ground and collects in the streets. 

Versions of Kinshasa’s story are playing out in large, crowded cities across Central Africa.

Terra Firma Rainwater Collective provides a household-scale nature-based solution to help adapt cities to a changing climate. We are one part of an integrated water management solution for ‘sponge cities’ that incorporates large infrastructure works with community-led solutions. Our in-country implementing partners live and work in the neighborhoods where we are installing rainwater collection systems, taking the lead role in expanding on the accepted social norms around rainwater harvesting.

Our solution addresses two market failures that have limited the scale of rainwater collection, even though it is an accepted social norm. First, local artisans sell sections of roof gutter without a viable way of attaching them to most roofs. To address this, we developed and patented a thermoplastic Roof and Gutter Clip (see here) to attach a rainwater collection system to the ubiquitous, and often poorly-constructed, corrugated metal roof. This clip attaches to the drip edge of the metal roof with a single bolt, providing an arm to support the common 13-cm wide gutter. The clip has a circular hinge to accommodate any roof angle and a vertical riser to allow a consistent gutter slope, even when the roof edge is uneven (see https://www.tfrain.org/learn-more-prototype-1). The ability to collect roof water to a single point radically changes the potential scale of water collection. 

The second market failure we address is an affordable solution for storing meaningful quantities of rainwater. We are using ferrocement, which is a sand-cement mortar spread over a wire frame. This is a common tool around the world but has yet to see wide use in Congo. Instead, large storage tanks are currently made of plastic or reinforced concrete, which are twice the price of our alternative. The ability of a family to collect, store, and use 5,000 to 10,000 liters of rainwater can translate to an at-home water supply for up to 9 months of the year in Congo. The added benefit of using ferrocement is that it creates local employment opportunities and a maintenance economy already exists for materials and methods we employ.

With the combination of a water storage tank connected to an infiltration well, along with minor grading and revegetation of the parcel, our data suggest we can reduce runoff by 50 to 70 percent for high intensity rainfall events. When applied at scale, this could keep monsoon runoff amounts below the threshold for a new ravine to form or grow. This preventative outcome begins to repair a broken urban water cycle by providing an at-home water source, safer and cleaner neighborhoods, and an incremental impact on the existential crisis of impromptu landfills and associated water pollution. 

Terra Firma Rainwater Collective’s target demographic begins with the 12+ million residents in Kinshasa who do not have access to domestic water at home and are some of the most climate-vulnerable people in the world. The households we serve can spend a significant amount of their income buying and hauling water. When flooding and erosion destroy transportation routes, water systems, and powerlines, the most basic tasks of daily living become a challenge.

Access to a convenient and safe water supply is a primary concern for the people in these communities. The quality of both surface water and groundwater are notoriously poor. In urban areas, 42 percent of residents use unimproved sanitation facilities, so E-coli is a widespread contaminant in unimproved ground water supplies (USAID, 2021). Water quality is expected to continue to degrade as projected population growth outstrips the government's ability to provide services in the coming decades. Our solution begins to give local communities some control over their water-related future by providing a seasonal source of at-home water while incrementally addressing the paralyzing issue of urban flooding and erosion.

Given that the unemployment rate is about 22 percent, we have sought to craft our work around the creation of small-scale economic activities. Our system design and installation, particularly construction of a ferrocement water storage tank, creates direct economic opportunities for people in the construction, materials, and transport trades. Local families also generate income from growing food or re-selling collected water to neighbors for a cheaper rate than it can be purchased elsewhere.  

Although we are currently implementing projects primarily in Kinshasa, we are working with partners in Brazzaville, the capital city of the Republic of Congo, where the same issues exist. Our solution can be applied to the monsoon climates around the earth, rural and urban, where rain is plentiful and pollution is rampant. 

Our Team Lead, Mark Weinhold, first began working on this issue in 2018 at the request of the US Embassy on behalf of the Congolese government. In his official capacity with the US Government, he quickly realized that the usual high-level government intervention would never arrive here; there needed to be a distributed solution that empowered residents to solve their own problems. That is the creation story of Terra Firma Rainwater Collective. 

Over the following years we developed relationships with our implementing partners, shaping a team that combined our decades of technical expertise in hydraulics and hydrology and our access to resources (both financial and technical) with our partner’s local expertise and integration in the communities we serve. Our primary implementing partner in Kinshasa is the Centre d’Etudes Environnementales pour le Developpement Durable (CEEDD), an NGO created by past graduates of the University of Kinshasa who were looking for ways to lift their communities, particularly related to sustainable development and adaptation to a changing climate. The president of CEEDD, Eric Lutete-Landu, is completing his PhD evaluating the urban flooding and erosion issue in Kinshasa and beyond.  

Our Congolese team currently consists of three administrative staff and up to 8 masons who build rainwater collection systems. Of the administrative staff, one of those positions focuses solely on community outreach and education. This means talking with community members about their issues around water supply and management, including how to scale their efforts at collecting rainwater. 

At Terra Firma, we cannot (and should not) be the face of our work in Congo. Rather, we empower, support, and provide technical assistance to our local team as they create a positive impact in the communities they call home. Three of our stateside board members work for the US Government, so our built-in ability to connect with organizations like USAID, US Forest Service International Programs, World Bank and United Nations, has been extremely beneficial to moving our work forward.

We recently completed 100 rainwater collection systems spread over ten different neighborhoods in Kinshasa, DRC. These systems provide a seasonal water source for about 700 people. Through this process we have been iterating on our construction methods for ferrocement water storage tanks and on the design and materials for our Roof and Gutter Clip that allows attachment of a gutter to (often uneven) corrugated metal roofs. 

For the Roof and Gutter Clip, we received a patent in the United States (US11,346,109 B1, May 31, 2022), with assistance from the NYU Law School Patent Clinic. During the prototype phase we were 3-D printing the clips and shipping them to Congo, a very expensive process since each print was nearly $40. Shaped by input from local roofers and architects, we completed four different batches of 3-D prints, slightly modified with each version, before we commissioned an injection mold. Our mold now resides in Chicago where we can mass produce the clips for about 85 cents each. We have approximately 1,500 of these clips in service, so our task now is to develop the business plan and associated supply chain to get this product in the hands of people who need it.

With the ferrocement tanks, we have worked through any number of bugs, primary among them has been training and retaining a dependable labor pool. Over the last three years we have fine-tuned our process to get consistent results by searching out sources of quality construction materials and innovating on the use of metal forms to make our tanks fast to build, durable, and aesthetically pleasing. We can build a ferrocement storage tank, employing many people in the process, at half the cost of a comparable plastic tank.

We are working with USAID, US Forest Service, and World Bank to develop large-scale plans to address these urban issues. This means creating long-term project plans for comprehensive Nature-based solutions (e.g. Sponge Cities) that include large infrastructure, but also an essential focus on community-led interventions like we are piloting.

Terra Firma Rainwater Collective’s strength as an organization lies in our ability as engineers to problem solve, foster relationships with international aid organizations and governments, and work closely with our in-country implementing partners to create meaningful change. Yet we fully recognize that any solution that is intended to benefit millions of people needs to have a market-based component. That is, our materials and methods need to be readily available for the eventual ‘payer at scale’, which is both international aid organizations and ordinary people in marginalized communities around the world.

We seek guidance from Solve’s team of international exports in three different areas that are all related to business models. First, we need to solidify a business plan around the production, distribution and sale of our roof gutter clip. We have done preliminary market research in Kinshasa and are confident in its financial future, but that conclusion is heavily dependent on decisions on where it is produced, how it is shipped and distributed, and how tariff systems are managed at the border. We have approximately zero expertise in this area.

Second, although we are relatively young in our process, our relationships with large aid organizations mean we need to be poised to quickly scale our work. We expect this might occur initially as subcontracts with large international consulting firms like TetraTech or DAI, but developing a model for an organizational structure to support this potential scale will be critical in the years to come. 

Third, to meet demand for the public in general, we seek guidance on the feasibility of developing a franchise-based model for the installation of complete water catchment systems. We are currently operating within a pay-for-service model that is subsidized with philanthropy in order to get exposure for our work across Kinshasa. That puts us in the position of a microfinancier, which is not a role we want to take on in the long term. 

Finally, we would like to work with experts in the Solve network to fine-tune our impact assessment and reporting.

Managing runoff from monsoon rains in cities like Kinshasa is not an optional activity. It is an existential necessity. We see our solution as a necessary component of WASH strategies that seek to address the tangled issues of climate change, water quality and availability, solid waste management, and human health. Our work is community-based which makes it readily accessible to the general public as well as a complement to larger Nature-based Solutions envisioned by large aid organizations. 

Our Roof and Gutter Clip (Patent US11,346,109 B1) is changing the playing field by making water collection possible on nearly all corrugated metal roofs. We see this as a catalyst for other economic activities like gutter production and sales, small-scale food production, and re-sale of collected water.

Our other innovation is to build large water storage tanks from ferrocement, which is affordable, made from readily available materials, and is easy to learn and master. Construction of these tanks create economic opportunities around construction labor, materials supply, and transportation. In addition, they can be built for half the cost of a comparable manufactured plastic tank.

Our goal is that a rainwater collection system is eventually considered an integral part of any roof, no less important than the corrugated metal itself. 

Our Theory of Change has social, physical, and economic channels that all culminate in an impact of improving the lives of climate-vulnerable and marginalized communities. Our current focus is in Central Africa, specifically the mega cities of Kinshasa, DRC and Brazzaville, RoC, although our model is applicable to developing countries with monsoon climates around the world. 

For the physical channel of our Theory of Change, we are focusing inputs to support the distribution of our Roof and Gutter Clip into the construction materials marketplace, development of franchise teams to install complete rainwater catchment systems, and implementation of demonstration projects to create ‘social proof’ of the value of collected water in key neighborhoods in Kinshasa and Brazzaville. The outputs are measured most simply as the number of systems installed around these cities. When a system is installed, runoff is managed so the likelihood of flooding and erosion is reduced in proportion to the adoption rate by local households. In addition, water is available at home for domestic and agricultural uses for up to 9 months of the year. Our post-project interviews with clients confirm the time, money, and life changes that result from our work.

For the social channel of our Theory of Change, our inputs are directed to support opportunities for women and youth. We actively recruit, hire, and train staff to meet this intent. Working through local churches, orphanages, and NGO’s that support women, we have been successful in providing life-changing opportunities within this demographic. We understand that there is a business case for this as well. Research in Africa is clear about the benefits of women’s economic empowerment; 90% of income earned by women directly benefits children and the family (Clinton Global Initiative) whereas 35% of men’s earnings is invested back into their families. We have direct experience with this phenomenon where men earn a paycheck and disappear for a week. Empowering women with useful skills and income has a generational benefit. 

The economic channel of our Theory of Change is geared toward the benefits of small and local economic opportunities. In the most direct case, inputs are the purchase and transport of construction materials (sand, cement, wire mesh, etc.) from local markets. Related is the direct employment of laborers to install complete systems, either by direct hire or subcontract. Indirect opportunities we have observed are the re-sale of water to neighbors at a cheaper price (or more convenient) than they can fetch it, and production of food for consumption or sale. In some cases, where sporadic piped water is available, residents will fill our tanks with water to use when the public supply is not operational, which is much of the time.

In each case, for each channel, we see incremental increases in the stability of the lives of the community members we work with. Our immediate task is scaling this impact within the social and economic confines that Central Africa presents.

The most basic formulation of our impact goals are: If rainfall runoff is managed at the household scale through rainwater harvesting and infiltration measures, urban flooding and erosion will be reduced and residents will have a seasonal at-home water supply. If flooding and erosion are reduced and clean water is collected, detrimental effects of these disasters (human health from pollution and economic loss) will be reduced, resulting in more water-related climate resilience and adaptive capacity. Additionally, if we demonstrate the efficacy of rainwater harvesting and create a paradigm shift that normalizes these activities, then implementation of this paradigm will create economic opportunities (labor, materials supply, business creation) for people of various ages and skill levels.

We currently measure progress toward these goals as:

• Number of catchment systems installed

• Customer satisfaction with those systems via interviews

• Number of families with augmented income from system installation via interviews

• Number of Roof and Gutter Clips in circulation

• Change in rainfall-runoff relationships before and after implementation (initial data collection in progress)

When our solutions are scaled, we expect to make a meaningful contribution to the following UN Sustainable Development Goals and Targets:

SDG 1 - No Poverty

• Target 1.5: Indicator 1.5.1 Loss of human life from disasters;

SDG 6 - Clean Water and Sanitation

• Target 6.3: Indicator 6.3.1 Maintaining good ambient water quality of water bodies;

SDG 8 - Decent Work and Economic Growth

• Target 8.6: Indicator 8.3 Employment opportunities for youth; 

SDG 11 - Sustainable Cities and Communities

• Target 11.5: Indicators 11.5.1 through 11.5.3 Loss of human life, economic losses, and damage to critical infrastructure from disasters; 

• Target 11.6: Indicator 11.6.1 Proper management of municipal solid waste; 

SDG 13 - Climate Action

• Target 13.1: Indicator 13.1.1 Loss of human life from disasters

We lean heavily on appropriately low-tech, socially accepted, and sustainable technology. People know the value of collecting water from monsoon rains, but the low quality of corrugated metal roof construction typically leaves an inconsistent elevation on the drip edge of the roof and the rafter sizes, spacing, and materials do not readily accept a fascia board. In other words, a traditional gutter system cannot be attached to most roofs. We solved that with our Roof and Gutter Clip that attaches directly to the roof edge, providing a hanger arm for a gutter to rest. We use thermoplastic (glass-filled nylon) to endure the equatorial heat and solar radiation. With our recently commissioned injection mold, we can produce these clips for about 85 cents each. 

The other core technology we lean on is ferrocement, a sand-cement mortar spread over a chicken wire frame. Again, this is not a new material/technology, but has yet to see widespread use in Congo. The attractive aspect for our work is that it uses commonly available construction materials, is easy to learn and master, and provides an enclosed space that mosquitoes cannot access to breed. What is more, making ferrocement water storage tanks creates construction-related employment for many people, compared to the purchase of a ready-made plastic tank.

Based on our engagement in these communities thus far, we strongly believe that the best tech is low tech - capitalizing on the maintenance economy that already exists for any material or method we introduce.

All our paid staff members are in Congo. We have four administrative staff members that cover all day-to-day operations and logistics, financial management, and community engagement. Our construction team currently consists of 8 masons who focus on building ferrocement water storage tanks. We use contracts with local workers for materials transport and rain gutter fabrication and installation.   

Currently, our US-based operations are accomplished by a working board and volunteers. This means that nearly all the money we raise goes directly to the people who need it most. 

Mark Weinhold started working on these water-related issues in Congo in 2018 through a request from the US Embassy. In his official role with the US Government, he realized that a distributed solution, implemented home by home, was needed. Terra Firma Rainwater Collective received nonprofit status in April 2020 and began work with implementing partners soon after. 

We have a guiding policy for DEI where we have taken what felt like typical lofty language and tried to create specific objectives applicable to our situation. For example, one of our four primary themes for our organization is to support youth, women, and girls. We have been intentional about having women lead our in-country team. Of our four primary leadership and management positions, three are held by women. In the US, Terra Firma’s small working board has an equal gender mix. The racial makeup is 25% Hispanic, 25% Asian, and 50% White.

In Kinshasa, we work with church leaders, NGOs supporting single mothers, directors of orphanages, etc. to find young people who want to learn a trade and who need an opportunity to jumpstart their working lives. This has proven to be a very successful strategy for us to develop a workforce. We understand the multiplier effect that income earned by women has on children in a family.

Another more subtle aspect of our relationship with DEI is how we (Americans) engage in Central Africa. We have a strong relationship with our in-country implementing partner, but we see ourselves as supporting their community-focused efforts. From that position, we can be instrumental in supporting real change while constantly learning and adapting to the social and cultural landscape required for success. 

Our value proposition at the core of our business model canvas is, For urban poor in Central Africa who need water for domestic uses and agriculture, we provide the means to harvest rainwater off corrugated metal roofs, thus avoiding contaminated surface and groundwater sources, preventing flooding and erosion, thereby turning excess roof runoff into an opportunity and long-term cost savings. Unlike other methods only available for expensive, well-constructed roofs, our products make this opportunity available to all.

Our near term identified customer segments are urban poor who pay for and haul water for domestic use, some of whom are in flood-prone areas (15%), households seeking economic or food benefit through urban permaculture or water re-sale (15%), peri-urban development starting new construction in steep, erosion-prone terrain (40%), Governments or NGOs working in this sector (20%), contractors and suppliers (10%).

Our business model currently considers three revenue streams. The first is product-based, with distribution and sale of our Roof and Gutter Clip. Second is a pay-for-service franchise model for installation of a complete catchment system. Third is complete system installation via contract/subcontract with international aid organizations implementing large-scale Nature-based Solutions that include both infrastructure and community-based components. 

We see our work fitting as a hybrid embedded and integrated model, since our for-profit components can be integral to advancing our nonprofit mission. Key partners for our nonprofit segment are implementing NGOs in Central Africa, private philanthropy, and international aid organizations (e.g. USAID, Word Bank, United Nations, etc). Key partners for our for-profit segment are local manufacturers, suppliers, shippers, and contractors.

Our revenue model has three components: philanthropy, subcontracts and partnerships with international aid organizations, and a market-based component with product sales and franchise models. 

First and foremost, we are an established 501(c)(3) nonprofit. We have used philanthropy to develop our approach and techniques, and intend to continue down that path. We have thoroughly tapped the Friends and Family phase of nonprofit growth and have been successful in receiving small grants ($5,000 to $25,000) from small family foundations. This can be a significantly larger revenue source for us, but finding foundation partners and developing those relationships takes time. We are not yet big enough to be eligible for large foundation grants, but are working in that direction. 

Secondly, our background as US Government engineers/hydrologists who have worked internationally since 2010 gives us a solid foothold in fostering relationships with international aid organizations (World Bank, UNOPS, USAID, etc.). We know and have access to the players in the WASH arena, are familiar with their local portfolios, and understand their priorities, objectives and intended outcomes. For example, we were recently asked by the World Bank in Congo to cooperatively develop the concept note to shape the upcoming phase of their water-climate project in Kinshasa, DRC. They recognize the need for our community driven Nature-based Solutions to round out their larger infrastructure-focused projects. Initially, we will likely subcontract with large international consulting firms who regularly work with USAID, World Bank, etc., until we are large enough to profitably navigate that landscape.

In the market-based space, we are using our own hired crews to determine the price point for full cost recovery of complete water catchment systems under different scenarios. We have implemented one hundred of these systems with our own financing system, but are looking toward partnerships with banks and micro lenders to keep our energy focused on implementation. Our second for-profit model is centered on the production and sale of our patented roof clip for attaching a gutter to these corrugated metal roofs. As mentioned earlier, we can manufacture the clip in the US for about 85 cents and can sell them in Kinshasa for between $2.00 and  $4.00 each, but there is still ample investigation to be done to finalize a business model that minimizes production, shipping, and tariff costs. This includes the possibility of local production, although quality control becomes a key concern. Here is where we could really use mentoring and expert advice.