Rainwater management
Rainwater management is a series of countermeasures to reduce runoff volume and improve water quality by replicating the natural hydrology and water balance of a site, with consideration of
The continuous growth of human populations and the consequent growing need for drinking water is a global problem.[1] Rainwater is an important source of drinking water, and as a free source of water, considerable quantities can be collected from roof catchments and other surface areas for various uses.[2] Due to water shortages, rainfall events and flooding, attention has been given to rainwater management. Rainwater management re-conceptualizes urban rainwater, transforming it from a community risk to a resource for urban development,[3] a good rainwater management is important for the design of sanitation systems and the environment, nowadays different methods of rainwater management have been developed,[4] including reduction of impervious surfaces, separation of rainwater and sanitary sewers, collection and reuse of rainwater, and Low-impact development (LID). [[1]].
Components
Rainwater harvesting and use

Rainwater harvested from roof structures or other compact surfaces is discharged through drains into storage tank, processed by treatment systems and then deployed in use facilities to complete the beneficial use of rainwater. Rainwater so treated is mainly used for irrigation, washing, laundry, and in some countries it is also considered as drinking water after the necessary purification.[1]
Urban flood management

Gray-green infrastructure
The use of
Constructed wetlands
Constructed wetlands for sewer overflows treatment are currently an effective and less costly option to prevent untreated wastewater from overflowing from polluted natural water bodies, and constructed wetlands that act as retention ponds during the rainy season can collect and treat rainwater due to their natural purification function, and produce high quality water for reuse after treatment by constructed wetlands with aeration system and soils infiltration system.[4]
Separate sewer systems
The conversion of
Land use
The ratio of pervious to impervious surfaces is important in flood management.[11][12] Building vegetated spaces, such as parks integrated with urban facilities, can increase the amount of pervious area.[13] For new and redevelopment projects, reduce the amount of impervious surfaces, such as buildings, roads, parking lots, and other structures.[14]
Low-impact development (LID)

Low-impact development (LID) refers to systems and practices that use or mimic natural processes that result in the infiltration, evapotranspiration or use of stormwater in order to protect water quality and associated aquatic habitat.[15] Low-impact development (LID) practices provide more sustainable solutions than traditional piping and storm ponds in rainwater management.[16] The sustainability of LID practices is achieved primarily through the use of porous pavement, bioretention, green roofs, rainwater harvesting, and other rainwater management strategies. Bioretention can effectively retain large amounts of runoff, porous pavement can effectively infiltrate rainwater runoff,[17] and green roofs can retain rainwater under a variety of climatic conditions.[18] These methods create and restore green space and reduce the impact of built-up areas at the site and regional scales, promoting the natural flow of water within an ecosystem or watershed. Applied over a wide range of scales, LID can maintain or restore the hydrologic and ecological functions of a watershed.[15]
Rainwater management in agriculture
Applying rainwater management, surface runoff can be collected and stored in hand-dug farm ponds.[19] To enhance irrigation in dry conditions, earthen ridges were constructed to collect and prevent rainwater from flowing down the hillsides and slopes. Even during periods of low rainfall, enough water can be collected for crop growth.[20] Rainwater management can increase the productivity of smallholder farmers in arid environments. Productivity of rainfed agriculture is improved through supplemental irrigation, especially when combined with soil fertility management.[21]
Tools
Rainwater management as a means of multi-stage control and improvement of rainwater systems needs to go through multiple steps of analysis and design, and in the new era of
Terminologies
Low impact development (LID)
The term Low-impact development is commonly used in North America and New Zealand, and was first used in the United States by Barlow et al.[22]
Water sensitive urban design (WSUD)
Water sensitive urban design (WSUD) is a concept widely accepted and partially acted on throughout Australia's federal and state governments.[23]
Integrated urban water management (IUWM)
IUWM derives from the broader term, Integrated Water Management, which involves the integrated management of all parts of the water cycle within a watershed.[24]
Sustainable urban drainage systems (SUDS)
SUDS established in a similar but separate design manual that includes Scotland and Northern Ireland as well as England and Wales,[25] SUDS consists of a range of techniques and technologies based on the concept of replicating the natural, pre-development drainage of the site as closely as possible, culminating in a management system.[26]
Best management practices
Best management practices are structural, vegetative or managerial practices used to treat, prevent or reduce water pollution. Structural BMPs. Extended Detention Ponds.
See also
- Integrated urban water management
- Urban flooding
- Constructed wetlands
- Low-impact development
- Water-sensitive urban design
- Sponge city
References
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- ^ ISSN 1878-0296.
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- ^ "Rainwater Harvesting for Livestock". www.ntotank.com. Retrieved 2021-12-13.
- ISSN 2073-4441.
- ^ S2CID 234190451.
- ^ a b US EPA, OW (2015-10-13). "Combined Sewer Overflows (CSOs)". www.epa.gov. Retrieved 2021-12-13.
- PMID 30771676.
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- ^ "Reduce Impervious Areas | Low Impact Development". lidcertification.org. Retrieved 2021-12-13.
- ^ a b US EPA, OW (2015-09-22). "Urban Runoff: Low Impact Development". www.epa.gov. Retrieved 2021-12-13.
- S2CID 7579497.
- S2CID 30609563.
- ISSN 0169-2046.
- ISSN 1474-7065.
- ^ "Rainwater harvesting | Food and agriculture | Practical Action". 2019-05-08. Archived from the original on 2019-05-08. Retrieved 2021-12-14.
- ISSN 0012-8325.
- ^ Barlow, Deborah, George Burrill, and James R. Nolfi. A research report on developing a community level natural resource inventory system. Center for Studies in Food Self-Sufficiency, Vermont Institute of Community Involvement, 1977.
- ISBN 978-0-12-812843-5, retrieved 2021-12-14
- ISSN 0022-1694.
- ^ Martin, P.; Turner, B.; Waddington, K. (2000). "Sustainable urban drainage systems Design manual for Scotland and Northern Ireland". www.opengrey.eu. Retrieved 2021-12-14.
- S2CID 53142230.