Landscape-based regeneration of the Nile Delta's waterways in support of water conservation and environmental protection

Waterways’ regeneration is proposed as one of the main mitigation strategies for addressing the alarming water budget deficit in the populous, hyper-arid Egypt, relying primarily on the Nile as its most important water source. The latter is increasingly under pressure from a rise in internal consumption, droughts, and upstream damming. We perform herein a review of the state of knowledge of waterways in the Nile Delta and the environmental drivers that resulted in their degradation. We evaluate how these degradations are associated with the decadal changes in their socioeconomic context and how these changes impacted the public perception of the waterways’ functionality from irrigation canals to sewage sites. The above led to littering, pollution, and negligence toward their preservation, which consequently accelerated their gradual landfilling as a response to their contamination triggering severe public health and ecosystem degradation concerns. The extensive landfilling further compromised their role in crop production, water conservation, and ecosystem integrity. We review and compile several published reports and perform field investigations to assess the current state of knowledge on the physical degradation of waterways in the Nile Delta for the last 60 years. Our results suggest that the alarming increase in informal settlements, resulting from multiple economic shifts and rapid urban sprawl, is the primary cause of waterways degradation and landfilling as well as the reduction in their total area by ∼30 % from ∼207,912 ha in 1987 to ∼146,381 ha in 2019. We suggest a landscape based design built on the Nile’s natural heritage to efficiently regenerate the areas surrounding these waterways to enable their role in addressing the water budget deficit and ensuring sustainable ecosystem services.