Yield–reliability analysis for rural domestic water supply from combined rainwater harvesting and run-of-river abstraction

Abstract

Yield-reliability analysis for rural domestic water supply from combined rainwater harvesting and run-of-river abstraction. Hydrol. Sci. J. 56(2), 238-248. AbstractIn many rural areas, reticulated water supply from large water resources schemes does not exist and many households obtain water from groundwater (GW), rainwater harvesting (RWH), run-of-river (ROR) flow, or combinations of these. While comprehensive yield-reliability analysis for large water resource systems is the norm, typical rural water supply analysis unrealistically aggregates data into monthly or annual time steps and does not incorporate reliability. A daily time-step simulation of household supply and frequency analysis of the number of days supplied in each year is used herein to: (a) demonstrate a realistic approach of yield-reliability analysis for RWH, ROR and combined RWH and ROR supply; and (b) show how combined utilization of the two can lead to improved supply. Integration of RWH and ROR supply has been found to improve yield and reliability substantially. The limitations of using the simpler mass curve analysis and the effect of applying a monthly time step are demonstrated.

Generalized Storage–Yield–Reliability Relationships for Analysing Shopping Centre Rainwater Harvesting Systems

“…Daily time step simulation of RWH systems has been used to provide data for generalizing storage-yield-reliability relationships [26][27][28] and for other analyses [22,[37][38][39][40]. Simulation also forms the basis of most RWH modelling tools [9].…”

Yield-reliability analysis and operating rules for run-of-river abstractions for typical rural water supply: Siloam Village case study

“…This shows that the domestic water requirements can only be met at a high level of supply service at relatively low LAS compared to the recommended LAS by DWAF (2004) to be met at these LAS, then other sources of supply would be required to supplement the ROR supply. For example, Ndiritu et al (2011a, b) showed that integration of RWH and ROR supply improves yield and reliability up to 96% (1:25) for a period of 9 months. This underscores the need to integrate all of the available sources of water to supply the water requirements in water-scarce rural areas at the recommended LAS.…”

“…Over the past few years, it has become quite clear that in large parts of South Africa, and particularly in rural areas, people experience acute water shortages. Reticulated water supply from storage reservoir systems is not common and less capital-intensive set-ups, including boreholes, run-of-river (ROR) supply and rainwater harvesting (RWH), serve as the main sources of water (Ndiritu et al, 2011a). In rural areas of the country, unregulated ROR abstractions are common.…”

“…While comprehensive yield-reliability analysis for large water resource systems with storage dams is now the norm, typical rural water supply analysis unrealistically aggregates data into monthly or annual time steps and does not incorporate reliability (Ndiritu et al, 2011a). Mallory (2005) noted that models used in SA such as 'water resources yield' and 'water resources planning' models have been successfully used to implement water restrictions/operating rules for systems dominated by storage dams, but little attention has been given to ROR schemes.…”

Sustainability Analysis of Domestic Rainwater Harvesting Systems for Current and Future Water Security in Rural Mexico

“…Rainwater harvesting has been identified in many areas as an economically feasible solution to reduce strain on current water supply systems and provide optimal water quality. In addition, it is seen as an adaptive measure to address climate change effects on precipitation variability (Ndiritu et al, 2011). Rainwater harvesting has been an appealing alternative for rural populations, especially where a centralized water supply system is not viable (Barron, 2009).…”