During the hot months of summer a lot of water is required to keep a large garden looking good. Fortunately Dawn Gardens has an inexpensive source of water from a canal about a mile away.
The canal delivers water to an 8” pipe through stainless steel filtering screens to homeowners in Iron Mountain Estates and to Dawn Gardens.
Dawn Gardens gets 4 miner’s inches which is about 45 gallons per minute delivered 24 hours every day from April 15 through October 15. The other days of the year we have to use well water but irrigation water is seldom used at that time. The nice thing about canal water is that it requires no pumps since it is delivered to my property in a 2” pipe at 150 psi.
This is enough to operate the entire irrigation system, the waterfalls and 10 water features at no cost except for the yearly water use fee of about $1400. When I have to use the wells it cost $600 per month in electricity costs.
The largest irrigation heads at Dawn Gardens are these Hunter rotors which are watering the grass garden. These are turned on only once a month in the summer for 4 hours.
These rotor heads can use 4-10 gallons per minute depending on the size of the nozzle and are spaced 40-50’ apart.
The most common spray irrigation method is the pop-up spray head:
The spray head maximum diameter is 15’ and it usually has a precipitation rate of 1 1/2” per hour. In contrast, the rotors have a precipitation of about 1/2” per hour which means that you have to leave the rotors on 3 times as long to apply the same amount of water as spray heads.
Spray heads have a low trajectory so they usually have pop up nozzles so the spray can clear the foliage. But if the heads are too close to the foliage deflection will occur and plants in the back will not get enough water. Since the precipitation rate is so high there is a lot of runoff and waste.
So bring on drip irrigation.
80% of Dawn Gardens is irrigated by drip. It is 50% more efficient than spray or rotors because water gets to the plants and not the weeds.
Here are 2 drip emitters installed on a 1/2” PE drip line. They are dripping at the rate of 1 gallon per hour (1 GPH) and we usually install 2 emitters for each gallon size plant and water it for 1 hour 3 times per week.
If plants need more water we can install shrubblers or spectrums:
The shrubblers are adjustable and emit water from 0 to 10 GPM.