Why Rain Harvesting?
Collecting water is rain barrels and other storage units is actually a very old tradition. Historical records show that it was a practice that dates back over 2000 years to Thailand and other ancient countries. Even in the “Olden Days” pioneers gathered water for watering plants and animals and even for household duties such as washing clothes.
It is a common belief that there is an indefinite amount of water available. Rainwater is a renewable resource, however most municipal water plants draw their water from aquifers. Many aquifers are being used faster than nature can refill them.
Rain harvesting is a way of minimizing the effect on municipal water supplies.
To put it in prospective, our world has a limited supply of fresh water. 70% of the Earth’s surface is covered in water but only 2.5% is actually fresh water. The rest is salt water. Much of the fresh water is in the forms of ice glaciers and the ice caps. Leaving 3/10 of 1% in the form of lakes, streams, and rivers. Unfortunately this actual small amount of usable fresh water is in danger of constant contamination by runoff.
So this is where rain harvesting comes into play. We can do our part in the form of rain gardens, rain barrels, and rain harvesting storage systems. All of these are ways to contain the runoff of your property and can make rain water into a usable commodity instead of runoff that gathers pollutants along the way and emptying into the sewer systems, streams, and lakes.
Besides being environmentally friendly you also save money. Using this rainwater you can sufficiently decrease your water bill especially in the hot summer months. Rain water can be used to water your plants indoors and outdoors, water your lawn, wash cars, and much more. Rain water is naturally soft and does not contain minerals, chlorine, fluorides, and other chemicals.
Plants respond to rainwater because that is what they strive on in nature. Therefore rain water is much healthier for your plants and plants respond better to the rainwater.
Have you ever noticed how you can water your plants just barely keeping them alive and the first time it rains the plants perk up and flourish?
You just have to decide which is the best application for you to use and you too can do your part!
The Statistic of Rain Harvesting
One inch of rainfall on a 2000 sq ft roof generates 1250 gallons of reusable water. The average rainfall for the Kansas City, KS area is approximately 37″. Your annual runoff of this same 2000 sq ft roof would be 46,250 gallons per year.
To calculate your potential reusable water, measure the length x width (be sure and add for your eaves on each side of the house). So overall l x w gives you your total roof catchment area. Multiply this number by the average rainfall per year in your area and it will give you your annual runoff potential.
Most rain harvesting systems though are 70-90% efficient. With any system you can expect to lose some water by blowing wind and evaporation.
Tidbit: Did you know that running a sprinkler for 2 hours uses approximately 500 gallons?
Benefits of a Rain harvesting System
- Reduction in water bills and city storm sewer charges
- Ease up the demand on municipal water systems
- Not regulated by watering restrictions during the dry season
- Healthier for plants
- Reduces overall flooding and erosion problems
- A very effective use of water source
- Environmentally friendly
Listed below are the Two Main Options for Rain Harvesting
Option One: Rain Garden
There are several uses of rain gardens: one is a low lying area of your yard where you can use the plantings to help slow down and filter the runoff.
Another application is a pond side rain garden in which the runoff from your existing pond flows into this area when there are heavy rains that make your pond overflow.
A third application is running your down spout from your roof into a rain garden
Wherever you choose to place your rain garden keep in mind to use plants that like a lot of water but can withstand dry periods at the same time. The plants will absorb the excess water.
The only thing with rain gardens is that you can not personally use the rainwater to water other plants. Also as a precaution you would want to use Mosquito dunks since this water is usually not moving.
TOP TEN LIST OF FILTERING PLANTS
1. Water lilies- are not so much for filtering as aiding in clarity by shading the pond keeping the sun from getting to the algae and thus feeding it. (Great for ponds but will not work in rain gardens.)
2. Rushes and Reeds- these marginals create dense root mats. Absorb water-borne nutrients.
3. Taro- a tropical plant with elephant ear type leaves. Feed off the nitrates in the water.
4. Yellow and blue flag iris- prefer NOT being planted in pots thus maximizing their nutrient absorption.
5. Arrowhead-a tall vertical arrow -shaped leafed plant that loves nitrates. Great for bogs and islands.
6. Pickerels- great for stabilizing stream beds and pond banks. Has a dense root structure.
7. Water celery-great planted in gravel or islands. Mats of thick roots absorb nutrients.
8. Water hyacinth- large purplish long root masses absorb nutrients. (Great for Ponds but will not work in rain garden)
9. Oxygenators- These are the obvious of all filtering plants. Day gives off oxygen and night give off carbon dioxide. Help starve out algae.( Great for ponds but will not work in rain garden.)
10. Umbrella palms and papyrus- these tropicals are some of the best natural filtering plants.
Option Two: Rain Harvesting Storage System
Normally when you think of a storage system for storing rainwater you think of the old-fashioned cisterns. Cistern could be above ground at the side of the building or buried underground.
Some how the idea of a large cistern sitting on the side of your beautiful home does not sound that appealing.
But what if you could have a beautiful water feature and no one would even know it was a harvesting system? You could have a beautiful landscaped yard and store rainwater all at the same time.
Picture a pondless water feature complete with a waterfalls and stream. This system would keep the harvested water re-circulating and fresh all the time. It would prevent the water from becoming stagnant and stale.
By keeping the storage unit under the pondless water feature you can maintain the integrity and beauty of your yard. Then when you need to water your plants you just hook up to a spigot and the stored water is ready to use.
But what happens if you don’t want the water feature but still want the advantage of storing rain water. These storage units can be installed and covered with grass, planting areas, patios, and anything else you would like to have and no one will even know you have a rain harvesting storage units installed. Yard runoff and water from your roof down spouts can be diverted into this system.
Water from these units can be used to water your landscape plantings and even utilized for watering your grass.