Abstract:
This study assessed the performance and effectiveness of rainwater harvesting (RWH) systems in
supporting agricultural productivity in Napak District, Uganda, a semi-arid region increasingly
affected by rainfall variability and water scarcity. The research was guided by four core objectives:
(1) to evaluate the design and hydraulic performance of existing RWH systems, (2) to assess the
impact of RWH systems on soil moisture retention and crop water availability, (3) to examine the
socio-economic and cultural factors influencing adoption, and (4) to analyze the effectiveness of
RWH systems in supporting different farming techniques and practices. Field surveys, geospatial
measurements, climate data analysis, and hydrological modeling (including the SCS-CN method
and unit hydrograph) were employed. Soil moisture data was collected using satellite-derived
SMAP datasets and validated with community observations. A comparative agronomic analysis
was conducted between RWH adopters and non-adopters to determine differences in planting
cycles, crop types, and irrigation practices. Socio-economic survey results revealed that income,
training, and land ownership were major enablers of adoption, while gender, cultural beliefs, and
lack of awareness acted as key barriers. Results show that where actively used, RWH systems
significantly improved dry-season crop production, crop diversity, and planting frequency,
particularly in areas like Nakichumet. However, underutilization of systems in other locations
limited their impact. Climate analysis revealed that current systems are vulnerable to changes in
rainfall intensity and distribution, requiring adaptive redesign. The study recommends enhanced
farmer training, integration of local RWH committees, and targeted expansion of systems in
underserved areas to strengthen resilience and food security.
