In this study, an instream constructed wetland treatment (CWT) was developed, with a focus on enabling the widespread adoption of new nature-based, low-cost and efficient technologies among smallholder farmers and communities in rural and isolated areas in El-Wahat El-Bahariya, where access to fresh water is limited and sanitation utilities do not exist. The developed CWT technology system, besides being an efficient and cheap technology for treating domestic wastewater and agricultural drainage water, increases the non-conventional water availability in water-scarce regions, reclaims nutrient-rich effluent for irrigation purposes, preserves the groundwater and surface ponds from pollution, reduces the environmental impacts and is considered a good application of the circular economy concept for the smallholder farmers. Two CWT systems were developed, tested and evaluated.