WaterSmart Yard - Watering Recommendations

Civic Plus ImageCurrent Irrigation Schedule Recommendations, last updated September 17th, 2020. The Watering Index this week* is 58%.

These free weekly watering recommendations for your yard are also available through a recording at 707-543-3466.

Irrigation Type Minutes
​per Week
# Watering
# Start
Grass (Pop-Up Spray)
18 1 - 2 1 - 2 A
Grass (Rotor / Impact)
48 1 - 2 1 - 2 A
Low Water Plants (Drip)
16 1 1 B
Moderate Water Plants (Drip)
33 1 1 B
Low Water Trees**
- - - C
Moderate Water Trees**
- - - C

*Watering recommendations are calculated to replenish soil moisture lost through evapotranspiration last week and do not take forecasted weather into account. Additionally, suggested run times are based on an irrigation efficiency of 100%. While drip irrigation is about 95%, sprinkler efficiency varies greatly. Please adjust as needed for your yard.
*For younger trees, follow the recommendations for the appropriate water use plants until roots are established. Typically, this is around 15 gallons 2 - 4 times per week. For mature trees, apply the recommended water once a week slowly to avoid runoff. For larger, well-established trees, apply twice the amount of recommended water every two weeks. Trees should be watered in multiple locations within the drip line (canopy) of the tree.
*Click on the How to Program Your Irrigation Controller 1 video below for detailed instruction on how to program your irrigation controller.

Example Water Schedule

30 minutes total per week, 3 watering days and 2 start times, set your timer as follows:
  • Program - 5 minutes run time with 2 start times (5 a.m. and 6 a.m.) set to water Tuesday, Thursday, and Saturday.
For help determining sprinkler type, precipitation rates, or information about using WaterSmart for your entire garden, call 707-543-3985.

Adjusting Controller Settings Based on Watering Index

If your timer has a "Seasonal Adjust" or "Water Budget %"option, you can use the Watering Index to adjust the schedule on your controller, without having to adjust each watering time entry.
  • First, set your controller's season or budget to 100%
  • Then enter a complete program for a warm summer month's schedule (what July would need)
  • Next adjust your controller's "% adjustment" with the watering index below to match the current weather. This should be adjusted weekly.
  • You may want to consider adjusting the number of watering days and start times for your peak (100%) schedule in both the early and later part of the irrigation season.
*Suggested run times are based on an irrigation efficiency of 100%. While drip irrigation is about 95% efficient, sprinkler efficiency varies greatly.
Irrigation Type
Minutes* (Peak Week)
Summer - Watering Days & Start Times
Spring & Fall - Watering Days & Start Times
Grass (Pop-Up Spray)
45 3 - 4 days / 3 start times
2 - 3 days / 1 - 2 start times
Grass (Rotor / Impact)
120 3 - 4 days / 3 start times
2 - 3 days / 1 - 2 start times
Moderate Water-Use Plants (Drip)
65 2 days / 2 start times
1 day / 1 start time
Low Water-Use Plants (Drip)
32 1 - 2 days / 1 start time
1 day / 1 start time

Weather Data Source

Santa Rosa Water has two weather stations linked to the State of California’s CIMIS program:
  • Station #83 on Llano Road on the West side of town
  • Station #158 at the Bennett Valley Golf Course on the East side of town
 Weather data from these two stations are averaged and then used to create the WaterSmart Yard irrigation scheduling recommendations.

Historical Data

Reference Evapotranspiration (ETo) Data (Inches)

Displays reference evapotranspiration rates for cool season turf 4 to 6 inches tall, well watered, and densely planted in large pastures.

Rainfall Data in Inches

Displays rainfall data collected at CIMIS stations in Santa Rosa.

ETo Minus Effective Rainfall (Inches)

Combines the data of the first two tables. Because not all rainfall received is useful to plants, rainfall data has been adjusted to account for this. That is why the title of this table refers to "effective rainfall."

The following documents contain evapotranspiration data and rainfall data for our weather stations on the East and West side of Santa Rosa. The document is separated into three sections: