Pressures on the globe’s water resources are straining aquatic systems around the world as global demand rises.
Population expansion and economic development are the main drivers behind the ever-increasing demand for freshwater supplies.
Water harvesting pumping systems will become more popular in the coming century as municipalities. homeowners, business owners, and commercial and industrial building owners realize the benefits of capturing, storing, filtering, and using harvested rainwater for purposes such as flushing plumbing fixtures, irrigating parks and fields, washing laundry and vehicles and as mechanical makeup feedwater for industrial processes.
There are numerous advantages to using water harvesting pump systems.
They lower water bills and relieve pressure on municipal systems.
More importantly, they minimize the demand for our limited supply of drinkable water.
What is the meaning of a rainwater harvesting system?
Rainwater harvesting is the process of collecting and storing runoff from a building or other impermeable surface for later use.
Rainwater collects in the gutters, which channels it down the downspouts and eventually into a storage container.
Rainwater collection systems can be as basic as collecting rainwater in a rain bucket or as complex as gathering rainwater into big cisterns to meet your household’s complete requirements.
Rainwater harvesting component
Transporting rainwater through pipes or drains, filtering it, and storing it in tanks for reuse or refilling are all components of a rainwater harvesting system.
These steps are demonstrated with the common components of a rainwater collection system.
Catchments: The catchment of a water harvesting system is the surface that collects rainwater quickly and delivers water to the system.
It can be a paved area, such as a building’s terrace or courtyard, or an unpaved area, such as a lawn or open ground.
Water can be collected from a roof consisting of reinforced cement concrete (RCC), galvanized iron, or corrugated sheets.
A coarse mesh on the roof to prevent debris from passing through.
Gutters: Rainwater is collected and moved through channels that surround the edge of a sloping roof.
Gutters are built mostly of plain galvanized sheet iron and can be semi-circular or rectangular.
Gutters must be covered so that they do not droop or fall off when filled with water.
The method gutters are erected is mostly determined by the house’s construction; typically, iron or timber brackets are affixed to the walls.
During the most intense rain, the gutter size should be determined by the river.
It is recommended that you oversize them by 10% to 15%. Gutters must be covered so that they do not droop or fall off when filled with water.
The way gutters are attached depends on the construction of the home; iron or timber brackets can be placed into the walls, but for houses with larger eaves, some sort of connection to the rafters is necessary.
Conduits: The conduits are pipes or drains that carry rainfall from the catchment or rooftop area to the irrigation system.
Conducts can be made of any commonly available material, such as polyvinyl chloride (PVC) or galvanized iron (GI).
First flushing: A first flush device is a valve that guarantees that runoff from the first rainstorm is flushed outside the system and does not enter it.
Filter: The filter removes suspended pollutants from rainwater gathered on the roof.
A filter unit is a chamber filled with filter media like fiber, coarse sand and gravel layers that remove silt and dirt from the water before it enters the storage tank or recharges the structure.
Charcoal can be used for further filtering.
Charcoal water filter:
In a drum or an earthen pot, a basic charcoal filter may be created.
Gravel, sand, and charcoal make up the filter, which is all readily available
Filters made of sand:
Sand is a widely accessible filter medium in sand filters.
Sand filters are simple to install and affordable.
These filters may effectively reduce turbidity (suspended particles like silt and clay), color, and microbes in water.
In a basic sand filter that can be created at home, the top layer comprises coarse sand, followed by a 5-10 mm layer of gravel, then another 5-25 cm layer of gravel and boulders.
Storage: In terms of tank shape, height, construction material, and placement, there are several possibilities available for the building of these tanks: – Cylindrical, square, and rectangular shapes are available.
Construction material: RCC, Ferro cement, masonry, plastic (polyethylene), and metal (galvanized iron) sheets are often utilized.
Tank placement: These tanks might be built above ground, partially underground, or completely underground, depending on available space.
To guarantee the quality of the water contained in the container, several maintenance actions such as cleaning and disinfection are necessary.
Recharge constructions: Rainwater may be charged into groundwater aquifers through a variety of structures, including dug wells, borewells, recharge trenches, and pits.
Some recharge structures facilitate water percolation at lesser depths via soil layers (e.g. recharge trenches, permeable pavements), whereas others convey water to deeper depths where it reaches groundwater (e.g. recharging wells).
Existing buildings such as wells, pits, and tanks can be used as recharge structures at several locations, eliminating the need to update some.
Rainwater harvested quality
When it comes to rainwater gathering, water quality is a major consideration.
The water quality needs may vary depending on the application, but the water quality of the gathered water may also fluctuate across time and distance.
Many variables influence the water quality of rainfall collected.
Chemical, microbiological and physical pollutants are the three categories of contaminants.
Contaminants are taken up by the raindrops as particulate matter or as solutes as soon as they leave the clouds.
The roof is a second significant source of pollution.
The material on the rooftop and the deposits on the rooftop might have an impact on the water collected there.
Finally, the quality of the water may deteriorate during storage.
When measuring water quality, it’s important to distinguish between chemical and microbiological water quality.
The chemical water quality is generally acceptable and close to that of drinking water, although fecal contamination and bacterial regrowth may be seen in most cases.
An extra disinfection process, such as filtration and/or UV disinfection, may be necessary depending on the use of the collected water.
Reference
[1] Rainwater harvesting system technology, [online] Available at: https://www.britannica.com/technology/environmental-infrastructure
[2] Rainwater harvesting 101, [online] Available at: https://www.watercache.com/education/rainwater-harvesting-101
[3] Rainwater harvesting, a sustainable solution for urban climate adaptation? , [online] Available at: https://edepot.wur.nl/345625
[4] Top 7 Types of Rainwater Harvesting Systems You Should Be Knowing, 2019, [online] Available at: https://gosmartbricks.com/top-7-types-of-rainwater-harvesting-systems-you-should-be-knowing/
[5] Components of Rainwater Harvesting system, [online] Available at: https://www.cseindia.org/components-of-rainwater-harvesting-system-657
[6] Important Rainwater Harvesting Components With Their Uses, [online] Available at: https://procivilengineer.com/rainwater-harvesting-components/
