Rainwater Harvesting Techniques
Rainwater harvesting techniques are employed as alternative source of water. In so many regions around the world, this is the major source of water.
This article will tell you everything you need to know about rainwater harvesting.
Rainwater Harvesting; What Does it Mean?
Rainwater harvesting is a technique used to gather, filter and store rainwater; which is later used for different purposes.
This rainwater is usually collected from natural and man-made structures.
For instance, rainwater can be collected as it drops from roof tops; rain water can be collected as it slides down hills or rocky surfaces; rain water held up in a compound can be packed.
Moreover, the rain water just needs to be collected before it goes as surface runoff.
Furthermore, rainwater is the main source for replenishing groundwater. However, due to some natural instability, groundwater undergoes depletion.
Rainwater harvesting is an artificial remedy for replenishing groundwater. It can also serve for consumption.
Lastly, rainwater harvesting systems are inexpensive and can be placed in any functioning building
Rainwater Harvesting Techniques
Collection of rainwater is done using two techniques. Harvesting surface runoff and harvesting rooftop rainwater.
1. Harvesting Surface Runoff
This technique is done by collecting water that flows on the ground during rainstorms. The water is collected and stored in a special storage space.
There are tanks and reservoirs designed for the sole purpose of storing surface runoff. Different techniques are employed to successfully save the water.
Also, certain steps have to be taken to make sure the water is clean.
2. Harvesting Rooftops Rainwater
This method is used mainly in individual and commercial buildings. Using the rooftop harvesting technique is collecting rainwater from roof catchments of buildings. The rainwater is diverted into a storage tank where it will be stored.
This water can either be used to satisfy the everyday needs of individuals or can be used in the artificial recharge system.
Why is Rainwater Harvesting Important?
- After filtration, the water can serve domestic purposes
- Rainwater harvesting is a way to boost groundwater recharge which will improve soil fertility.
- Rainwater harvesting ensures high quality water.
- Rainwater harvesting helps to reduce the need for groundwater.
- Rainwater harvesting increases the productivity of the aquifer; which in turn increases groundwater level.
- Rainwater harvesting is a method that helps to reduce the influx of salt water in coastal areas.
Rainwater Harvesting Advantages
- It is an affordable and accessible water resource.
- It helps to lessen the chances of urban flooding.
- It is a good way to prevent soil erosion.
- It doesn’t require intensive labor.
Rainwater Harvesting Disadvantages
- The water needs to be treated properly to serve for drinking purposes.
- It isn’t possible in areas where there is hardly any rain.
- Setting up rainwater harvesting systems is expensive. Just that initial payment.
- It takes time to maintain the storage spaces. Also, the area usually attracts bugs and insects.
- The water gotten from the system is based on the magnitude of the rain. It can vary during different seasons.
Rooftop Rainwater Harvesting Techniques
Rooftop rainwater harvesting has several techniques that can be employed. Here are some of those techniques.
1. Direct Use Storage Technique
This technique is done by directing the rainwater from the roof into a storage tank. Usually a gutter is attached to the roof, in order to direct the water.
Also, the storage tank differs because certain things have to be taken into consideration. For instance, the water consumption and the magnitude of the rain.
The pipes that lead the water to the storage tank should be equipped with filtering systems. Firstly, a flush device and then a mesh device which should be placed in the mouth.
Also, a method for water overflow should be present. This will transfer water to the recharge system while the storage tank remains filled. The water in the storage tanks can serve individual needs.
Lastly, this is the most economical method for collecting rainwater.
2. Groundwater Aquifer Recharge
There are different kinds of structures that can be used to replenish groundwater aquifers. These structures help to improve precipitation and reduce surface runoff.
Here are some of the techniques used to in this method:
- Filling up boreholes
- Recharging excavated wells
- Trenches for recharge
- Recharge pits
- Filtration tanks
- Shafts of recharge
Components of Rooftop Rainwater Harvesting
Here are some of the components of rooftop rainwater harvesting:
1. Catchment
In rainwater harvesting, the catchment is the surface where the rainwater drops. Obviously, for rooftop rainwater harvesting, the rooftop is the catchment.
2. Transportation
This is the component that moves the water from the catchment to the storage tank. There are some equipment that make transportation possible. Here they are:
3. Gutters
Gutters are attached to the roof. They provide a pathway that guides the water towards the storage tank.
4. First Flush Device
This device will ensure that debris in the gutter doesn’t follow the water into the tank.
5. Mesh Filter
This filter is placed at the mouth of the pipes to rid the water of debris.
6. Pipes
The pipes control the water into the tank
7. Storage Tank
The tank stores the rainwater inside it for later use.
