Domestic rainwater harvesting (DRWH) is playing a key role in meeting some objectives of the UN “2030 Agenda for Sustainable Development and building resilience to climate change, particularly in the Caribbean. Most recent promotion initiates of DRWH has been funded by external sources. However, DRWH projects can be implemented through self-financing, government subsidies, and micro-financing. Regional experiences show that generally, the high initial capital costs for DRWH systems is a major constraint, however, success is possible through self-financing in some cases.. This study reports on a review the experiences of some DRWH projects to determine a suitable financing mechanism. It is found that in most cases, households can self-finance DRWH systems if payments are based on 5% of household income and interest rates are less than 5%. It was found that the pattern of growth in DRWH systems followed a in step-like phased approach and fits well into product/business cycle. The next great leap in DRWH expansion requires, a strategic partnership between local and international NGOs, community based organisations and financial institutions like credit unions and the financial participation of beneficiaries.