Mediterranean irrigation
- To: m*@ucdavis.edu
- Subject: Mediterranean irrigation
- From: s* f*
- Date: Tue, 20 Jun 2000 10:08:01 -0700
I agree that no irrigation during the summer months is the 'pure'
Mediterranean method. But some of us do water to create a more lush
environment. I've found a method of irrigation that is very water
efficient. I've had great success with what's currently called 'Subsurface
Irrigation'. At my home I use mulch over newspaper and snake 'dripperline'
under the mulch. Dripperline is 18mm drip tubing with emitters factory
installed within the tubing. The emitters don't easily clog - they're very
sophisticated turbulent flow emitters spaced either12", 18", 24" (pardon
the non-metric) apart. I use 12" spacing.
The best dripperline is pressure compensating, made by Netafim, an Israeli
company. It was developed for agriculture. I first heard of it maybe 10-15
years ago. It was used around here in landscaping in highway median strips
near Vacaville, which is between San Francisco and Sacramento, California.
The summer climate there is windy and hot. The tubing is buried 4" (there's
that non-metric again) in the soil and covered with mulch. If the tubing is
laid in parallel lines, it can irrigate as throughly as sprinklers while
losing no water to wind or evaporation. I heard of an auto dealership in
the area that used this method under turf. The sprinklers were leaving
mineral deposits on the new cars. The owner took a gamble and switched to
subsurface irrigation of his turf. It supposedly works very well, giving
him the beautiful green turf with no overhead watering. He can ever
irrigate while people walk on the grass! Also I've heard of a sports field
near Stockton in California's central valley that is also successfully
irrigated by subsurface irrigation. If the tubing is laid with correct
parallel spacing, one can calculate the precipitation rate of an area and
base irrigation on the current ET rate (evapotransporation).
I just 'snake' the tubing in my own garden. The emitters use 2 liters per
hour of water. That's 200 liters of water per hour per 100'. Excuse my
mixing metric and non. I run into this all the time and it's driving me
crazy. I call 2 liters per hour, 1/2 gallon per hour, so that's 50 gallons
per hour or .83 gallons per minute per 100'. One can successfully water a
large area of shrubs or perennials with a very low water flow. I have a
well, so this is essential for me. I keep all flows at 3 gallons per minute
or less. If you use automatic valves and a timer and water at night and use
mulch you can have a beautiful garden with very efficient and thrifty water
use.
All in all, though, I've found the most important water conserving method
is the mulch over newspaper. We just had a heat wave here. Last Wednesday
the temperature was 110 deg. F in my garden. I've never seen it so hot. I
didn't lose one plant.
Steve French
Steve French Landscape Architect
2616 Meier Rd. Sebastopol, CA 95472
Laguna de Santa RosaTributary
Russian River Watershed
North America
tel: 707-829-1200
fax: 707-829-3967
sfla@monitor.net
www.stevefrenchlandscapearchitect.com
