Save water in your landscape with a properly set irrigation controller. Here are some tips to make setting your irrigation controller easier.

ADJUSTING RUNTIMES

Use the Seasonal Adjust % feature on the dial of your controller to make runtime adjustments to all your stations with a single adjustment. This is the easiest way to make sure your runtimes match the increasing and decreasing water needs of your plants throughout the season.

In spring, set your runtimes for each station according to what your landscape requires in July, then change your seasonal adjust% once a month to make sure your landscape is receiving just enough water. This can save water and money, while maintaining a healthy landscape.

PRECIPITATION RATE (PR)

Several factors determine how long you need to run your sprinklers. Sprinkler type, plant type and time of year are all factors that influence how much water we need to provide in irrigation. The Precipitation Rate of our sprinklers is simply, "how quickly our sprinklers apply water" and are listed as inches of water applied per hour of runtime in/hr.   

For example:

• Rotor type sprinklers apply water slowly and typically have a PR of 0.30-0.50 in/hr. 
• Spray sprinklers apply water very quickly with a PR of <1.0 to >2.5 in/hr.
• High Efficiency sprinklers apply water slowly and efficiently  at 0.40-1.0 in/hr.
• Drip irrigation is the most efficient and slowest application of water with a range of PR dependent on the emitter style chosen.

Calculating your precipitation rate can be done at home with a free rain gauge from the City of Bend Water Department.

LANDSCAPE PLANT TYPES = WATER NEED

Lawns in Central Oregon require an inch and a half (1.5 in) of water per week during peak season. Shrub areas require approximately half that amount. Native plants will only need periodic irrigation once established.

CYCLE AND SOAK

Many irrigation sprinklers will apply water faster than your landscape can use it. Using cycle and soak techniques means that we split our runtimes in half and add a second start time to  "cycle" irrigation in to smaller more manageable amounts. This can increase the amount of water that makes it to our plant roots through the soil as well as reducing runoff.

Instead of running each lawn sprinkler zone for 10 – 15 minutes each, run each zone only the amount of time that the soil can absorb the water (which means it’s not running onto the sidewalk or street).

EXAMPLE RUNTIMES

The charts below show examples of runtimes for an average irrigation system during the peak season month (July) in Bend. Notice that the total minutes per week needed are calculated, then divided by the  number of irrigation days per week on an even/odd day schedule. The cycle and soak splits this daily runtime in half and adds a second start time in order to maximize water infiltration and reduce runoff. Runtimes can be calculated if you know your systems PR rate  by dividing the weekly water need by the PR rate and multiplying by 60. For  example (1.5/2.5)*60 =45 minutes per week.  Check page 12 of the Irrigation Guide to see more information on calculating runtimes.

Drip Irrigation Example

SMART IRRIGATION TECHNOLOGY

Smart irrigation controllers automatically adjust irrigation in response to environmental conditions.  They differ from the standard irrigation controller in that they only water when the landscape needs it. Link to more information about smart irrigation controllers.

Tip

Use a soil probe, screw driver or hand trowel to monitor soil moisture.