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Chris Wagner
07-20-2004, 12:43 PM
Our irrigation system was installed last year. Now that we're getting deep into the dry summer months, infrequent, but deep waterings are growing important.

However, I'm not sure how long I should be setting each station. Installed were Hunter rotor heads and some Rainbird heads for some other areas. We have a pump as well and that runs on each station, but two.

I've heard about putting a coffee can out to measure water output in an hour. Is there a better way? If that is acceptable, can someone add some more details?

ProMo
07-20-2004, 05:39 PM
put out a few cans in each zone and run it for 15 minutes and measure the average depth of water multiply that by 4 and that will be how much your system puts out per hour. Then adjust the time so you are getting 1/2-3/4 in. per watering.

DGI
07-21-2004, 06:39 AM
Whatever you use, make sure it is cylindrical. I've seen some guys who use bowls and go from there. :D

Also, I'd go more than 15 minutes if for no other reason than the fact that you will be measuring a small amount of water and there is far more room for error.

aquamtic
07-21-2004, 02:26 PM
We use about 5 of these rain gauges to measure real world precipitation on our installs. We run a zone for 15 minutes and read measurment and determine how luch longer or less to run 1/4. That final determination is what we use for run times on an every other day schedule. This equals to the standard reqiement of 1" per week. On the hotter month we bump it up to equal 1.5" per week

http://www.edwardsironworkers.com/tru-chek/tandc.htm

Instant Rain
07-23-2004, 01:18 AM
When auditing the performance of a system I like to use graduated cylinders. They have a wide thought area and narrow base. If you use transparent ones you can greatly reduce time spent running stations and reading the results. Be very careful in securing them, they fall over easily.

Chris Wagner
08-09-2004, 05:15 PM
Thanks, aquamtic! I purchased one of those gauges and plopped it in the lawn. Interesting results so far.

On two of the rotor heads I tested, it would take about 2 hours to accomplish about 1 inch of water. These are larger zones, but still that seemed like a while.

Some of the Rainbirds were considerably less (obviously because the water is being poured on constantly). Basically 38-50 min to accomplish 1 inch of water.

Does this jive with some of your results? I've run the stations for about 20-30 min/week so far this season with fair results.

jerryrwm
08-09-2004, 09:09 PM
Once you have collected the data for the precipitation rate of the various zones, there is one more step that you can take to water the area properly and not waste water in the process.

Using 1" per week is a general rule of thumb thrown out by a county agent or garden center employee years ago when he was asked, "how much water should I apply?" Some weeks that may be enough, other weeks not nearly enough, and then other weeks way too much.

There are many other factors that need to be considered when setting the irrigation time for a particular yard, or even a particular section of the yard. Things like daily temperature, humidity, wind, hours of direct sun, soil type, grass type, etc, etc.

jerryrwm
08-09-2004, 09:35 PM
This is the rest of the post...got hung up on a phone call and didn't get a chance to complete the edit

Once you have collected the data for the precipitation rate of the various zones, there is one more step that you can take to water the area properly and not waste water in the process.

Using 1" per week is a general rule of thumb thrown out by a county agent or garden center employee years ago when he was asked, "how much water should I apply?" Some weeks that may be enough, other weeks not nearly enough, and then other weeks way too much.

There are many other factors that need to be considered when setting the irrigation time for a particular yard, or even a particular section of the yard. Things like daily temperature, humidity, wind, hours of direct sun, soil type, grass type, etc, etc.

Once you figure out the precipitation rate for each zone, you should find the E.T. rate for your area and water accordingly. Some areas publish E.T> rates in the paper - (Colorado used to). If they don't you can check with the National Weather Service in your area and they can give it to you.

With that data, you can determine how many days a week you want to water, then add up the E.T.s for that number of days, and set the time to water long enough for that amount.

Example.

Pr = 0.36 in/hr (rotor hds)

Water three days / week.

Weekly E.T. rate = 1.25" (over 7 days)

in/wk x 60 min
------------------------ = min/zone/day
Pr x # days


therefore:

1.25 x 60
------------- = 69 min/zone/day
.36 x 3


This way you are monitoring the system and replacing the water that has actually been used due to evapotranspiration by the turf or plants.

Just a little tidbit I thought I'd throw out.

Jerry

HBFOXJr
08-11-2004, 08:39 PM
Chris, I've written on this before. Search my old posts. There are formulas to calulate precipitation rates without measuring. We do it all the time and they are in Rian Bird and Hunter literature.

ET is important as stated before. This water schedule stuff is very easy whenyou know the precip rate and the ET for each month.

Here in southern NJ just east of Philadelphia our ET is close to 1.5" per week in June and July. The 1" per week always quoted in the AP garden articles of the paper are baseless in a global sense and irresponsible journalism.

Additionally I've found it works best to water once per day rather than the infrequent, deep stuff always being recommended. Don't knock it till you have tried it. I'm in my 4th season of this recommendation to clients who are not water restricted and practice it personally. The turf styays in superior condition and because it is never under any moisture stress.

To do so you must have a well designed and installed system with even and predictable precipitation rates and know your ET for each month.

We use nothing but Hunter controllers with the water budget feature. When we set up a new job the controller is programmed for June/July needs with the water budget at 100%. All the client does is go to their controller once per month and change the water budget to the appropriate percentage. All our irrigation months here require less water than June July so it is easy.

jerryrwm
08-11-2004, 09:47 PM
Harold,

I agree a lawn that gets watered everyday will never be under any moisture stress.

But, what happens when it misses a couple days or a week or more, and the temp is in the high 90's or over 100 for several days in a row (which is not uncommon here in South Texas and other parts of the country) and the wind is blowing about 12 - 15 mph and no cloud cover at night?

And missing a few days of watering can happen - Homeowners are out of town for a week or more, the power goes off, the transformer or controller craps out, and the watering does not happen, and they come home to a stressed yard that will take them a while to get back into shape. And who are they looking at? The irrigation guy who sold them this thing in the first place.

Personally I prefer to have them water less frequently, and deeper and then the lawn can withstand a few days with out water. In fact I encourage them to water twice on the watering days. Split the zone watering times in half, and run back to back cycles which give the water time to percolate and help eliminate or reduce puddling or run off.

I am also a solid proponent of water budgeting features and mixed programming. Completely different schedules for turf and beds. I encourage my customers to look at their system at least twice a month and look at the yard to see if it is looking the way that they want it.

For my money based on ease of use for the comsumer and reliability and features I use the Irritrol TC series controllers. All the functions are readily apparent, (no hidden key sequences) and simple to change. I have used and sold nearly every brand and model of controller on the market for the last 20 plus years and I keep coming back to this one. It costs more than many controllers out there, but with a 5 yr warranty and the Irritrol track record it's "Mi Gusto!"

Jerry

HBFOXJr
08-12-2004, 08:25 AM
Jerry,
What I didn't say is that the daily watering must be started with the soil fully hydrated and not in a deficit situation. The daily watering is meant to keep it topped off according to ET need.

So no matter whether daily or less often cycles, a fully hydrated root zone will only last but so many days no matter if the conditions are normal or extreme. The customer will see the same results no matter what goes wrong either way it is watered.

There are those that will talk about shallow roots with daily watering. Wrong! Roots will always grow down as far as possible with optimum moisture and fertility. If the theoretical root zone for a plant has moisture the roots will be there.

Trust me guys, this does work, it isn't theory.