Feasibility of Rainwater Harvesting and Consumption in a Middle Eastern Semiarid Urban Area

Abstract

Recent developments of Middle Eastern metropolitans, and the related soaring trend of population increase, is contemporary with the impacts of climate changes. This applies extra pressures to the centralized large-scale water treatment and distribution systems. Rainwater harvesting (RWH) for domestic urban activities can be a sustainable option of adapting with the rising demand of soft water in such an arid/semiarid area. A pilot system of rainwater draining and storage was constructed for alleviating parts of soft water scarcity in Mashhad, the second most populous city of Iran. Measurements were collected for two years at the drainage basin outlet and inside of a storage tank, which has been equipped for water harvesting purposes. We performed some preliminary stochastic analysis and evaluated probabilistic properties of the collected dataset, aiming to explain them with respect to the physical characteristics of the RWH system. Data clustering analysis confirmed that the quality of the water may change during rainwater draining and storage in the RWH tank. Particularly, sodium content of the sampled water in the drainage catchment illustrated higher variations, compared with the ones evaluated for the stored water in the reservoir tank. This can confirm that the quality of the stored water in the RWH reservoir is more stable than that obtained for each separate rainfall–runoff event. We assessed the potential of the harvested water in different consumption contexts, in light of some national and international water quality (physicochemical, biological, and toxic pollutants) guidelines. We relied on water quality indices (WQI) to interpret multiparametric properties of the collected rainwater from urban surfaces; consequently, the quality of the harvested water was categorized with moderate to almost good attributes. This makes it well suited for irrigation uses, which can play a relevant role against water shortages in the analyzed semiarid urban region. Otherwise, infiltration and treatments need to be performed if using harvested water for drinking consumptions (of human or livestock), some of which may be costly for local owners/uses. We provide some suggestions for improving efficiency of the system and enhancing the quality of the harvesting water.

The Potency of Obtained Clean Water from Rainwater Harvesting in Sikka District

“…Apart from that, environmental and climate conditions also affect the quality of the rainwater produced. Based on the aspects described previously, there are several parameters that determine the good or bad quality of clean water produced from rainwater harvesting, such as Color, Turbidity, TDS, pH, BOD5, COD, Na, Fe, Mn, Pb, Cd, Total Coliforms, Fecal Coliforms (Anuar et al, 2015;Asnaning et al, 2018;Ranaee et al, 2021). In order to maintain and improve the quality of clean water, several activities were carried out, such as creating sewers for initial rainwater, which could potentially contain dirty and toxic particles (Ranaee et al, 2021).…”

“…Based on the aspects described previously, there are several parameters that determine the good or bad quality of clean water produced from rainwater harvesting, such as Color, Turbidity, TDS, pH, BOD5, COD, Na, Fe, Mn, Pb, Cd, Total Coliforms, Fecal Coliforms (Anuar et al, 2015;Asnaning et al, 2018;Ranaee et al, 2021). In order to maintain and improve the quality of clean water, several activities were carried out, such as creating sewers for initial rainwater, which could potentially contain dirty and toxic particles (Ranaee et al, 2021). Filtration using activated sand and activated carbon media installed in rainwater harvesting technology is a useful activity to reduce levels of harmful substances such as heavy metals (Hedegaard and Albrechtsen, 2014).…”

Rainwater Harvesting to Address Current and Forecasted Domestic Water Scarcity: Application to Arid and Semi-Arid Areas

“…However, [7] focused only on the optimal allocation of the RRWH in the West Bank, while [40] focused on estimating potential RRWH volume. Other scholars treated separately the allocation and the estimation of potential RRWH [57][58][59]. This research contributed to the analysis of the capacity of the potential RRWH to cover water scarcity by quantifying the influence of RRWH on the current and future domestic water scarcity.…”

Effect of Rainfall Regime on Rainwater Harvesting Tank Sizing for Greenhouse Irrigation Use

“…Concerning the quality of the harvested rainwater for irrigation use, the basic requirements include low to medium salt content and low content in heavy metals and total coliforms [17]. Many studies confirm that the quality of the harvested rainwater is generally suitable for irrigation use according to the abovementioned requirements [18][19][20].…”